Document yGnN08rBL4w9rvdVj3G7zvG2

*7 /<r I - 4/- API TOXICOLOGICAL REVIEW BENZENE SECOND EDITION, 1960 i 6< / The information and recommendations contained in this publication have been compiled from source* believed to be reliable and to represent the best current opinion on the subject. No warranty, guarantee, or representation is made by the American Petroleum Institute to the absolute correctness or sufficiency of any representation contained In this and other Toxicological Reviews, and the Institute assumes no responsibility in connection therewith; nor can it be assumed that all acceptable safety measures are contained in this and other Toxicological Reviews, or that other or additional measures may not be required under particular or excep tional conditions or circumstances. The American Petroleum Institute, as sponsor of this review, takes no position as to whether or not any method contained herein is covered by an existing patent, nor as to the validity of any patent alleged to cover any such method. Furthermore, nothing contained in this review grants any right, by implication or otherwise, for the manufacture, sate, or use in connection with any method, apparatus, or product covered by letters patent. This review was prepared at the Harvard School of Public Health, Boston, Mass., under the direction of Professor Philip Drinker. Anyone desiring to submit addi tional information or proposed changes for consideration prior to reissuance of this review is requested to send them to the American Petroleum Institute. AMERICAN PETROLEUM INSTITUTE 1271 Avenue op the Americas New York 20, N. Y. Trice 25 Oni, 00 0B7RB4 CONFIOFNTTAI k. YZ0077431 API TOXICOLOGICAL REVIEW OF BENZENE I. Substance Benzene Formula: C#H* Structural formula: jf^j Molecular weight: 78.11 Synonyms: benzol phene II. Properties and Characteristics ** * Boiling point =80.1 C (176.2 F) at 760 mm. Melting point =5.4 C to 5.5 C (41.7 F to 41.9 F). Vapor pressure = 74.6 mm of mercury at 20 C (68 F). Liquid density = 0.899 g per milliliter at 0 C (32 F). Explosive limits = 1.4 to 8 per cent. Flash point = 12 F (closed cup). Refractive index*= 1.5016 at 20 C (68 F). Specific gravity = 0.8787 at 15 C (59 F). 1 mg per liter =313 ppm; 1 ppm=0.00319 mg per liter. Benzene is a clear, colorless liquid with a charac teristic pleasant odor at low concentrations and a dis agreeable odor at higher concentrations. It forms a highly flammable and explosive mixture with air at con centrations ranging from 1.4 to 8.0 per cent benzene by volume. Pure benzene burns with a yellow, luminous, smoky flame and is a fire hazard unless proper care is taken in handling and storage. Benzene is relatively insoluble in water (0.08 g in 100 ml of water at 22 C) but is readily miscible in all proportions with alcohol, ether, acetic acid, chloroform, carbon disulfide, carbon tetrachloride, and similar or ganic solvents. Commercial benzene is practically never pure and usually contains varying amounts of xylene, phenol, and toluene; commercial benzene also contains traces of carbon disulfide (0.2 to 1.0 per cent), thio phene (0.1 to 0.2 per cent), olefins, naphthalene, and similar substances. Chemically, benzene is the simplest of the aromatic hydrocarbons. It is relatively stable but is capable of a variety of substitution reactions such as chlorination, nitration, sulfonation, and alkylation. Benzene is an ex cellent solvent for most organic substances. " Figures refer to BIBLIOGRAPHY on p. 6. III. Manufacture, Uaca, and Possible Sources of Exposure Benzene is usually manufactured from catalytically reformed light naphthas from which it is isolated by distillation or solvent extraction. Benzene is used as a solvent in many applications. It is also used as a component of some motor fuels and as the raw material for the manufacture of a host of syn thetic chemicals. Examples are: styrene, phenol, aniline, DDT, chlorobenzene, cumene, nitrobenzene, diphenyl, cyclohexane, adipic acid, and detergents. Because of its volatility, benzene presents a vapor hazard. The vapor may arise from numerous handling operations, as well as from leaks and accidental spills. Skin contact is a possibility when handling or packaging. IV. Toxicology a. Acute Effect* Acute benzene poisoning generally results from the inhalation of relatively high concentrations of vapor. Exposure to air containing benzene in concentrations of 19,000 ppm to 20,000 ppm (61 to 65 mg per liter of air) may cause death within 5 to 10 min, whereas con centrations of 7,500 ppm (25 mg per liter) are dan gerous to life In one-half to one hour.4 Severe toxic effects may be caused by 1-hour exposure to concen trations of 1,500 ppm (4.8 mg per liter). Concentra tions of 500 ppm (1.6 mg per liter) may lead to symp toms of illness when exposure continues for more than a short time.4 Inhalation of 50 ppm to 150 ppm (0.10 to 0.48 mg per liter) of benzene for 5 hours caused slight headache, weariness, and lassitude. The red-blood count de creased, the white-blood count was unchanged except for mild lymphocytosis, cosinopcnia, and monocyto penia. The albumin-globulin ratio increased slightly at lower concentrations but decreased with higher con centrations. The urinary coproporphyrins were in creased, whereas the urinary stiifjUe ratio was de creased.* Skin contact will cause dehydration and defatting which may lead to dermatitis. Systemic intoxication by cutaneous absorption is unlikely. Drinking benzene causes acute symptoms with local evidence of acute irritation of the mouth, throat, and stomach. A tablespoonful or less of benzene when swal lowed has been known to cause serious collapse. Subse- C HO 067885 CONFIDENT TAl YZ0077432 benzene 3 quently, h may result in bronchitis or pneumonia which Unquestionably, small amounts of benzene can be ab is probably caused by benzene entering the air passages.' sorbed through the akin, but it is very doubtful that ( Acute exposure to benzene exerts a toxic action on enough would be absorbed by this route to cause sys the central nervous system. Benzene first behaves as a temic poisoning.' stimulant--in the early stages of acute poisoning, per sons show excitement, euphoria, hilarity; then quite sud b. Chranie Effects denly this changes to weariness, fatigue, and sleepiness, followed by coma and death.1 Acute exposure to benzene produces rapidly increas ing symptoms of dizziness, excitation, and pallor, fol lowed by flushing, weakness, headache, breathlessness, constriction in the chest, and fear of impending death. Visual disturbances, tremors, and muscular weakness are also encountered. The victim may lose consciousness and pass into coma or may develop acute mania and de lirium. Convulsions occur frequently. Death may supervene almost at once or several hours to several days following exposure.* Recovery from acute benzene poisoning requires from one to four weeks. Immediately after exposure there are temporary symptoms of chest and head pains, shortness of breath, giddiness, nausea, and loss of ap petite. Evidence of unsteady gait, nervous irritability, and breathlessness may persist for two or three weeks, Chronic benzene poisoning results from repeated or continuous exposure to relatively low concentrations of benzene vapor. The level and degree of exposure neces sary to produce poisoning vary widely. There are at least two well-authenticated cases of poisoning by re peated exposures to 75 ppm." The toxic action Is exerted mainly on the hematopoi etic system. It may take months or even years to show harmful effects. Symptoms may be present over long periods, i.e. headaches, dizziness, fatigue, anorexia, and dyspnea. They may be varied and vague and not ob viously connected with benzene poisoning. During the early stages of poisoning, Heinz bodies may be present in the red-blood cells and a neutropenia is often seen. At this stage the blood picture may re turn to normal aftei removal from contact with benzene. As chronic poisoning progresses, nausea and vomit ing, burning sensations of the eyes and throat, and whereas cardiac distress and a peculiar yellow pallor to hemorrhages from mucous membranes, tongue, and the skin may last for as long as a month. Recovery from gums become manifest. Purpuric spots and ecchy- acute poisoning is generally complete after this period, moses may follow the slightest Injury, and epistaxis may ( although evidences of chronic benzene poisoning may occur. Menorrhagia, metrorrhagia, and spontaneous be encountered later.* abortion may develop in otherwise healthy women. Benzene also sensitizes the heart muscle to the action Blood examination at this point may show leukopenia of epinephrine, so that instant death may occur as a (below 4,000 white cells), neutropenia, and a severe result of ventricular fibrillation.1 Muscular activity in anemia. Later the platelet count falls so that thrombo- creases the rate and severity of acute benzene poisoning. penia is marked. The blood condition, at this stage, may Persons dying of acute benzene poisoning generally show have become irreversible. The clinical picture of a absence of clotting of the blood and widespread pe worker with chronic benzene poisoning at this stage is techial hemorrhages in the brain, pleura, pericardium, urinary tract, intestinal tract, mucous membranes, and characteristic--he complains of headaches, giddiness, drowsiness, lassitude, loss of appetite, and nausea with skin. There are no specific lesions of diagnostic im occasional vomiting. He looks pale; is short of breath; portance.* has a rapid pulse, a low blood pressure, and a mildly ele Local effects from acute exposure are seldom severe. vated temperature. He may also have epistaxis, bleeding Continued skin contact with benzene results in defatting from the gums, a purpuric rash, or subconjunctival of the skin and leads to erythema, dry scaling, and, in hemorrhages. The condition progresses slowly to acute some cases, the formation of vesicular papules. Pro leukopenia ending in fatal aplastic anemia.* Repeated longed exposure may produce lesions resembling firstor second-degree burns. It may cause considerable ir ritation of the eyes or mucous membranes of the nose and throat on contact. small doses of benzene by mouth can produce the same type of chronic poisoning.' Repeated contact of benzene with the skin will cause dehydration and delipidization predisposing to derma titis. Benzene poisoning by skin absorption has received scant attention in the literature. The possibility of per Benzene is relatively insoluble in body fluids and tis sues. Therefore, only small amounts arc absorbed by cutaneous absorption of benzene has been studied in the body. Equilibrium between blood and air is ap three cases. Immersion of the hands and forearms from proached within a few minutes after exposure is begun, / 25 to 35 min showed no evidence of skin absorption.10 and practically complete elimination of benzene from the D 067886 CONFIDENT IA( YZ0077433 4 API TOXICOLOGICAL REVIEW blood occurs within a few minutes after exposure is ter minated. Higher concentrations of benzene are obtained in tissues with 8 greater fat content, and saturation and elimination are more gradual.1' Human subjects inhaled benzene in concentrations of 340 micrograms per liter of air for 5 hours. Between 33 and 65 per cent of the inhaled benzene was retained (385 mg). During the desaturation period 3.8 to 27.8 per cent of retained benzene was excreted through the lungs and 0.1 to 0.2 per cent in the urine and other body excreta. Of the absorbed benzene, 9.7 to 42 per cent was excreted in the urine as phenol, 0 to 5.4 per cent as pyrocatechol, and 0.1 to 3.3 per cent as hydroquinone. Excretion of phenol and pyrocatechol was highest during the first 24 hours and complete in 48 hours, whereas hydroquinone took more than 48 hours. Excretion of organic sulfates in urine of exposed subjects was in creased. The opinion was expressed that benzene affects the metabolism of proteins, the metabolites of which are excreted in urine as ethereal sulfates.1' Benzene is unique in its myelotoxicity. It has been shown that the introduction of an alkyl group into the aromatic ring results in a loss of its myelotoxic property. This difference may be a result of the difference in the metabolic pathway. Benzene is metabolized to phenols and quinones which inhibit cell production. The in vivo metabolites of alkyl benzenes arc alcohols and carboxylic acids resulting from side chain oxidations. These com pounds have a low-order toxicity and are devoid of spe cific cell destructive effects.14 A variety of reactions may be encountered as the re sult of the chronic effect of benzene poisoning. There is little correlation between the degree and duration of ex posure and the severity or nature of the findings in the blood on microscopic examination.1' They may consist of a reduction in red-cell, white-cell, or platelet levels-- in any two of these or in nil three. These changes may develop gradually or suddenly. The blood usually shows a moderate reduction in red cells (below 3.5 million), white celts (below 4,500), and platelets. Blood exami nations for evidence of benzene poisoning should con sist of a complete study of red, white, and platelet frac tions. Progressive changes are more significant than the absolute levels. In anemia caused by benzene, it has been shown that there is a constant increase in scrum iron (average in crease, 213 micrograms) which is associated with a re duction of transferrin (average reduction, 225 micro- grams). The iron saturation of transferrin is above normal and is matched by iron saturation of the tissue. The cause of the disturbance of iron metabolism in ben zene poisoning is the failure of the marrow to utilize iron as well as increased intake of iron supplied parenterally by transfusion.1' There is some evidence that chronic benzene poison- ing produces a blood-clotting defect which is caused by functional and morphological as well as a quantitative alteration of the platelets.17 The marrow cells exhibit a decrease in peroxidase in benzene poisoning. Because benzene inhibits granulocyte maturation, it may act on peroxidase metabolites, or the peroxidase may be used up in detoxifying benzene." The bone marrow may be hypoplastic, fairly normal, or hyperplastic in appearance. Abnormal forms r young cells may abound, and leukemia as a result of chronic benzene exposure has been reported. Various individuals differ in their bone marrow response to ben zene-cases with symptoms fairly soon after exposure usually have fewer cells in the marrow, whereas cases de veloping later are more apt to have an increased number of cells in the marrow. It is believed that this represents an early weeding out of those who develop hypoplastic changes, rather than a gradual shift from one type of re sponse to the other."-" In a long-term follow-up of chronic benzene poison ing 4,538 cases were studied from 2 to 12 years after cessation of work involving exposure. There has been only one fatal case, six cases involving bone marrow changes, and one case of lowered resistance to infec tion.*1 The others were practically well but show varying degrees of neutropenia. Benzene is eliminated from the body via the lungs and the kidneys. In one study C-14 labeled benzene was given orally to rabbits. In 2 days 45 per cent of the dose was eliminated in the expired air (43 per cent as unchanged benzene and 1.5 per cent as carbon dioxide), and 35 per cent was eliminated as metabolites in urine (23 per cent as phenol, 4.8 per cent as quinol, 2.2 per cent as catechol, 0.3 per cent as hydroxyquinol, 0.5 per cent as L-phenylmercapturic acid, and 1.3 per cent as trans-, fra/u-muconic acid). Five per cent of the administered radioactivity was found in the tissues occurring mainly as metabolites." Certain factors have been noted which influence in dividual variation in susceptibility to benzene. Over weight individuals are more commonly -affected," and a low-protein, high-fat, low-Vitamin C diet is said to promote the disease. The presence of heart or lung dis ease and liver or kidney damage arc believed to pre dispose to the condition.14 Pregnant women may be more susceptible to benzene poisoning.4 Pathologi cal changes in ovaries, testes, thyroid, and pituitary are attributed to benzene; and changes in women work ers leading to sterility are emphasized." ( DO 067887 CONFIDENTIAL YZ0077434 BENZENE 5 t, RtMmneitM Ltak of Atmospheric EifOMN CThc generally recognized maximum acceptable con centration for benzene vapor is 25 ppm by volume in air (0.08 mg per liter of air) for an 8-hour daily ex posure.' In Germany the maximum permissible con centration to which workers may be exposed is 31.3 ppm by volume in air (0.1 mg per liter of air).*4 The Massa chusetts laws have established 25 ppm as a maximum benzene concentration.4' V. Treatment Acute benzene poisoning should be considered an acute emergency. Remove the victim from further ex posure at once and call a physician immediately. The patient should be kept warm and quiet in the recumbent position. If breathing has stopped, artificial respira tion should be started at once. Oxygen should be administered by a qualified person as long as necessary to maintain the normal color of skin and mucous mem branes. This may prevent the development of severe pulmonary edema. Stimulants will rarely be necessary when adequate oxygenation is maintained.1 Care should be taken that rescuers are not also over come by vapors. Chronic benzene poisoning is extremely refractory to treatment. It is roost important that the condition be / diagnosed early and the individual withdrawn from fur^ ther contact with the hydrocarbon. Blood transfusions are temporarily useful in combating severe anemia. VI. Examination The pre-employment examination should include a detailed history, physical examination, chest X-ray, and complete blood count. Workers with organic disease of the heart, lungs, liver, or kidneys should be elimi nated, as should those with a history of previous ben zene intoxication or evidence of an abnormality of the blood or blood-clotting mechanisms.41144 Periodic re-examinations should be carried out regu larly, the frequency being determined on the basis of the probable degree of exposure. The examination should include a brief interval history and physical examination, together with a complete blood study. The presence of any of the blood changes described require re-examina tion at least twice at intervals of one week and a thorough study of the working conditions. Unless there is noticeable improvement on re-examination, the worker should be withdrawn from further exposure. The following changes call for re-examination: whiteblood count less than 4,000, red-blood count less than C 4,000,000, hemoglobin kss than 12 g per 100 ml (80 per cent), blood platelets less than 100,000 per cu mm, differential count less than 50 per cent poly morphonuclear leukocytes, and more than a very few immature blood cells. The urine sulfate test may be used, not as a diagnostic test, but as a measure of the degree of the current benzene exposure. It does not measure the degree of benzene poisoning nor the blood changes present.1 VII. Precautionary Measures The safety measures necessary for the prevention of benzene poisoning are primarily those designed to pre vent the inhalation of benzene vapor. Proper ventilation, local exhaust, and closed systems should be used to maintain a concentration below the maximum acceptable concentration of 25 ppm by volume In air. AU apparatus and piping should be inspected regularly and sys tematically for leakage. When excessive concentrations are unavoidably encountered in operations such as the cleaning of tank cars, vats, or storage tanks, air masks and protective clothing should be employed.44 Employ ees should be fully instructed regarding health hazards which may be present in the handling of benzene and should immediately report any unusual symptoms r illness. Clothing wet with benzene should be removed promptly. If the hands are likely to have contact with benzene, impervious gloves or protective creams should be used. Proper ventilation, routine plant inspection, control of benzene air concentration, and periodic medi cal examinations are all of the utmost importance.44 The concentration of benzene vapor in the air should be checked regularly in locations where the possibility of excessive exposure may be encountered. This may be done by a variety of procedures among which are the butanone method,4 the mdinitrobenzene reduction method,4 an absorptiometric method, and a photocolorimetric determination. The latter method in volves the nitration of benzene with Stepanov mix ture which forms mdinitrobenzene. This gives a color reaction with acetone in alkaline solutions. Under similar conditions toluene gives a faint violet color. Based on these photocolorimetric methods small quantities of benzene and toluene can be determined in air.-4 More recently a silica gel adsorption method has been reported.14 Accurate quantitative study of atmospheric benzene as low as 0.003 mg per ml (0.9 ppm) may be determined by adsorption on acti vated silica gel and elution with absolute alcohoL The benzene content is then determined spectrophotometrically according to ASTM Designation D 1017: Method - On n6?88a CONF TDFNTTAl YZ0077435 I 6 API TOXICOLOGICAL REVIEW of Test for Benzene and Toluene by Ultraviolet Spec trophotometry. The range of measurement is 0.003 mg to 1.28 mg per liter. The mean yield was approximately 98 per cent. There are a number of instruments on the market which measure hydrocarbon air contamination. The presence of more than one hydrocarbon vapor, however, produces erratic results. Mil. Bibliography I E. Browning, Toxicity of Industrial Organic Solvents, Industrial Health Research Board Report No. 80, London (1937). * M. G. Jacobs, The Analytical Chemistry of Industrial Poisons, Hazards, and Solvents, 399, Inter&cience Publish* ers, Inc., New York (1944). *C. D, Hodgman and H. N. Holmes, Handbook of Chemistry and Physics, 25th edn., Chemical Rubber Publishing Co., Cleveland (1941). * Y. Henderson and H. W, Haggard, Noxious Gases and the Principles of Respiration Influencing Their Action, 164, Chemical Catalog Co., New York (1943), * M. W. Goldblatt, "Research in Industrial Health in the Chemical Industry." Brit. J. Ind. Med. 12 1 (1955). Genichl Watanabe, Jun Yasbioka, Haruo Hondo, Masao Matouchi, and Takcro Sakaguchi, I. Sci. Labour (Japan) 19 70 (1953); from Chem. Abstr. 6051 (1954). ' 'Threshold Limit Values for 1959," American Con ference of Governmental Industrial Hygienists, AM.A. Arch. Ind. Health 20 266 (1959). ' J. B. Lurie, "Occupational Health Hazards in the Manu facture of Insecticides," S. Afr. Jour. Clin. Scis 3 212 (1952). * J, L. Svirbely, R. C- Dunn, and W. F. von Oettingcn, 'The Acute Toxicity of Vapors of Certain Solvents Contain ing Appreciable Amounts of Benzene and Toluene," J. Ind. Hyg. Toxicol. 25 366 (1943); and "The Chronic Toxicity of Moderate Concentrations of Benzene and Mixtures of Benzene and Its Homologues for Rats and Dogs," J, Ind. Hyg. Toxicol. 26 37 (1944). 10 G. L. Conca and A. Maltaglioti, "Study On Trans cutaneous Absorption of Benzene," Med. lavoro 46 194 (1955); from Chem. Abstr., 16232 (1955). II M. Bowditeh and H. B. Elkins, "Chronic Exposure to Benzene-I: The Industrial Aspects," I. Ind. Hyg. Toxicol. 21 321 (1939). " H. H. Schrenk, W. P. Yant, S. J. Pearce, F. A. Patty, and R, R, Sayers, "Absorption, Distribution, and Elimina tion of Benzene by Body Tissues and Fluids of Dogs Ex posed to Benzene Vapor," J. Ind. Hyg. Toxicol. 23 20 (1941). 11 J. Tcisinger, V. Bergerova-Fiierova, and J, Kudrna, "Metabolism of Benzene in Man," Charles Univ. (Prague), Pracovni Lekarstvl 4 175 (1952); from Chem. Abstr., 4181 (1955). 14 H. W. Gerarde, "Toxicological Studies on Hydrocarbon*," AMA. Arch. Ind. Health 13 468 (1956). "L, A. Erf and C. P. Rhoads, The Hematological Ef fects of Benzene Poisoning," J. Ind. Hyg. Toxicol. 21 421 (1939). UB. Pernis and L. Mareo, "Metabolism of Iron in Hemopatbies Due to Benzene," Med. lavoro 46 325 (1955); from Chem. Abstr., 14996 (1955). ,T G. Saita, E. Sartarclli, and F. Calaresu, The Blood Clotting Process in Chronic Benzene Poisoning," Med. lavoro 45 313 (1954); from Chem. Abstr., 11652 (1954). ** V. Prato and G. F. Rublno, "Bone Marrow Peroxidase in Benzene Poisoning," Univ. Turin (Italy) Minerva med. II, 357 (1954); from Chem. Abstr., 5662 (1955). * T. B. Mallory, E. A. Gall, and W. J. Briekley, "Chronic Exposure to Benzene-111: The Pathological Results," J. Ind. Hyg. Toxicol 21,356 (1945). * F. H. Hunter, "Chronic Exposure to Benzene-U; The Clinical Effects," J. Ind. Hyg. Toxicol. 21 331 (1939). 11 Karel Rejsek and Maria Rcjskova, "Long Term Ob servation of Chronic Benzene Poisoning," Acta Med. Scand. 152 71 (1955). '* D. V. Parke and R. T. Williams, "Studies in Detoxica tion 49, Metabolism of Benzene Containing C1* Ben zene," Biochem. J. 54 231 (1953). 11 A. Foil, "Le benzolisme professionel," Presse med. 41 6,129 (1933). c. E. A. Winslow, "Summary of the National Safety Council Study of Benzol Poisoning," J. Ind. Hyg. 9 61 (1927). J. L. Gutierret de Alies, "Sterility in Laborers Caused by Benzene and Other Solvents" Med y seguridad trabajo 31 4 (1954); from Chem. Abstr., 13556 (1955). **R. W. van Hoesen Korndorffer, `Toxicology of Sol vents," Piastica 4 11 (1951); from Chem. Abstr., 11178 (1955). " Mass. Div. of Occup. Hyg. Bull., Maximum Allowable Concentrations (1957). * Occupation and Health Encyclopedia of Hygiene, Pathology and Social Welfare, International Labor Office, Geneva 1, 228 (1930). * F. I. Berezovskaya, B. E. Reznik, and S. S. Gitis, "Photometric Determination of Benzene and Toluene," Nauch, Zaplskl, Dnepropetrovsk. Gosudarst. Univ, 43 45 (1953); from Chem. Abstr., 783 (1955). > "pcr Ovrum, Determination of Atmospheric Benzene Concentration by Displacement Following Adsorption on Silica Gel," Brit. J, Ind. Med. 13 210 (1456).. I960 DO 067889 OONFTOFNTTAl. I YZ0077436 ( API TOXICOLOGICAL REVIEWS SECOND EDITION Benzene (1960) .................................................................................................. $ .25 Butadiene (1959)................................................................................................ .25 Copper Naphthenate (1959)..................................................................................... 25 Naphthalene (1959).................................................................................................. 25 Naphthenic Acids (1959)......................................................................................... 25 Toluene (1960) .................................................................................................. .25 Xylene (1960) .......................................................................................................... 25 ( ( 00 Ob^ C,00F YZ0077437 C c- AT THE MARCH 3, 1981, PUBLIC HEARING TEXAS CHEMICAL COUNCIL TESTIMONY ON EPA'S PROPOSED NEW SOURCE PERFORMANCE STANDARDS FOR VOLATILE ORGANIC COMPOUND FUGITIVE EMISSION SOURCES My name is A. H. Nickolaus and I represent the Texas Chemical Council (TCC). The TCC is an association of 87 chemical compani s having more than 67,000 employees and representing approximately 90% of the chemical industry in Texas. Since over half of the nation's petrochemicals are produced by member companies operating in Texas, the proposed regulation is of vital concern to us. The Texas Chemical Council has joined with the Chemical Manufacturers Association (CMA) in the preparation of detailed comm nts on the proposed regulation, and our combined written comments will be submitted prior to April 6, 1981. Today, I would like to highlight some of our concerns about this standard. A. Definition Of Modification First, to start off on a positive note, at our request the EPA has added an annual allowance of up to 5 1/2% for "process improvements" so that small, routine changes made to an existing process unit will not in themselves subject it to the new source standards. We thank the EPA for this consideration. B. Performance Versus Equipment Standards, Etc. When dealing with facilities broader than a specific process or installation, the TCC believes the EPA should set both a performance standard and an equivalent equipment or work-practice standard. If a performance standard is not possible, then at least an equipment and an equivalent work-practice should be set. This would allow the Synthetic Organic Chemicals Manufacturing Industry (SOCMI) the flexibility necessary to design and implement the most efficient and cost effective compliance program. The EPA has failed to do this for pumps, compressors, and valves in the proposed standard; although the TCC believes it is feasible to do so. 1. Pumps & Compressors For both pumps and compressors, the EPA states in the pr ambl to this regulation (FR p. 1143 & 1144, Jan. 5, 1981) that a performance standard is not feasible because the application of measurement technology is technologically impractical. Yet in the January 1981 Preliminary Draft Control Technique Guideline for "Control of Volatil Organic Fugitive Emissions from Synthetic Organic Chemical, Polymer, and Resin Manufacturing Equipment", they specify measurement of emissions from these pieces as the means of determining compliance. Do 067891 CONFJOFNTTA! YZ0028967 cC 2 The TCC recommends and requests that a similar monitoring option for pumps and compressors be added to this standard. 2. Valves In Gas 6 Light-Liquid Service Contrary to the EPA's opinion, the TCC believes that a performance standard for valves in gas and light-liquid service is feasible. Snee and Kittleman of Du Pont have shown (Letter from T. A. Kittleman, Du Pont, to Glynda E. Willins, Radian Corporation, November 13, 1980) that a leak level of 2% is equivalent to the basis used by the EPA in the BID to estimate the leak reduction effectiv ness of the proposed regulation. The TCC recommends that the EPA specify 2% of valves leaking as a "good performance" level that is equivalent to the prescribed monitoring program. C. Emissions Abatement The proposed standard requires that emissions be transported through a "closed vent system" to an "enclosed combustion device" or vapor recovery system and then defines an "enclosed combustion device" so as to exclude flares. We take particular exception to this. The TCC in our June 30, 1980, comments to the EPA on the Draft BID provided data showing 99+% efficiencies for a properly designed flare system. The EPA has taken a position, without any data, that flares may be only 60% efficient and that the burden of proof of better is on the SOCMI. We disagree. We have provided necessary data which should not be rejected arbitrarily. Further, since flares are standard abatement devices of long standing in both the chemical and petroleum-refining industries, we believe the burden of proof, with data, is on the EPA. The SOCMI has a heavy investment in flares and will strongly resist EPA's position that they are not acceptable emission control devices. We recommend that the definition of "closed vent system" be modified as follows: "Closed Vent System means a system which is not open to the atmosphere and which is composed of piping, connections, and, if necessary, flow inducing devices that transport gas or vapor from fugitive emission sources to a device which provides 95% abatement or to an enclosed combustion device, vapor recovery system, properly designed flare system, or an equivalent control device as determined by paragraph 60.484." D. Monitoring Frequency The rational approach to how frequently monitoring for leaking valves should be performed (60.462f) would be based on a costeffective analysis of leak occurrence and recurrence data. The EPA DO 067892 CONFIDENTIAL YZ0028968 cc -3- has not done this. Instead, in the preamble (FR p. 1146, Jan. 5, 1981) they state clearly their basic commitment to a monthly monitoring schedule - apparently as an article of faith. In the BID the EPA has assumed an occurrence frequency biased to favor a monthly program (see attached Figure 1). In the absence of definitive data, the TCC finds it difficult to justify anything but the assumption of a lin ar leak occurrence with time. Using a linear relationship, a quart rly monitoring frequency gives the Bame results as the EPA claims for their monthly program (again see Figure 1). The TCC has and continues to recommend that the required data be obtained and that a rational analysis of monitoring requirements be made. Until that time, the TCC believes the data in the BID cannot justify anything more frequent than quarterly monitoring. The TCC recommends that monitoring requirements in the proposed standard be changed to a true quarterly frequency. E. Leak Definition As the EPA has correctly pointed out, most leakage comes from only a few valves, and the problem is to find and repair these. The EPA has proposed 10,000 ppmv as the definition of a leak. Recent EPA data show variations of nearly an order of magnitude in repeat measurements of leak rates on the same valve. For this and other reasons more fully developed in our written comments, the T.CC again r commends that a leak be defined as 20,000 ppmv or greater. The leakage reduction attained will be essentially the same as at the 10,000 ppmv cut-off; but maintenance will be reduced by up to 30% as less maintenance effort will be spent on valves with inconsequential leak rates. F. Alternative Standards We commend the EPA for providing in paragraph 60.483 provisions for alternative standards. But in terms of monitoring programs, what the EPA giveth with one hand it taketh away with two. The problem is that an allowable percentage of valves leaking must be determined after the plant is built. Quality control experience shows that quality must be built into a product; it cannot be inspected in. Thus, the time to assure a low-leakage plant is in the original design before the plant is built. But a plant providing the best leak "prevention options would have to meet a much lower allowable percentage valves than one not so well designed, and consequently, it would have much less opportunity for a reduc d monitoring program than a poorly designed plant. This doesn't make s nsej low-leak plants should require less inspection - high-leak plants more. D0 067893 CONFTOFNTTAl. YZ0028969 fc - 4, - What is needed is an incentive for owners to build low-leak plants. Some assurance of an opportunity for reduced monitoring requirements in such plants would provide this. In our written comments (60.463c Good Performance Incentive), we detail a statistical monitoring plan which resultB in reduced monitoring requirements for those who meet a "good performance" level equivalent to the BID basis. The TCC strongly advocates the adoption of this proposal. Th advantages of a quality control approach is (1) greater emission reductions will be realised industry-wide because there is an incentive to do so, (2) the monitoring burden will be lessened on low-leak plants and increased on high-leak ones, and (3) well d fined rules on what can and cannot be done will be available to the owner at the design stage. G. Determination Of Equivalence (60.484) Although the TCC believes guidelines for approval of equivalent or alternate means of emission limitation should be specific so that, having met them, approval by the EPA Regional Offices is more or 1 sb authomatic; the proposed paragraph 60.484 seems to be overly detailed without accomplishing this purpose. The procedure in Subpart Ka, paragraph 60.114a for Standards of Performance for Storage Vessels for Petroleum Liquids Constructed After May 18, 1978, is simpler, more straight forward, and we prefer it to the present proposal. H. Reporting, Recordkeeping, Etc. The TCC believes that the proposed tagging, recordkeeping, and reporting is excessive and goes beyond that necessary to implem nt the required program and also beyond that required for compliance. In our written comments, we make detailed recommendations to corr ct this. I. Need & Costs In closing, whether it is legally appropriate or not, we cannot resist again stating our belief that this regulation is unnecessary and that the costs have been under-estimated. We re-affirm the comments we made to the EPA on June 30, 1980, and we recommend them to your attention. Finally, on costs the EPA is still basing monitoring costs on two man-minutes per source despite their own data in Table C4 of th bid showing it took highly motivated contract workers an average of 3.4 minutes to perform this task. AHN/rtg 2-20-81 D0 ofeyem CONFIDENT! Al- YZ0028970  BEFORE THE ENVIRONMENTAL PROTECTION AGENCY COMMENTS OF THE CHEMICAL MANUFACTURERS ASSOCIATION A "t> TV*A4 CHtmlC+C COl/HCU. ON EPA'S PROPOSED RULEMAKING OF NEW SOURCE PERFORMANCE STANDARDS FOR VOLATILE ORGANIC COMPOUND FUGITIVE EMISSION SOURCES. UNDER THE CLEAN AIR ACT Proposed Standards of Performance ) for New Stationary Sourcee; VOC ) Fugitive Emission Sources} Synthetic ) Organic Chemicals Manufacturing ) Industry, 46 Federal Reqister ) 1136 (January"? / "I57l) ) ______________________________ ') DOCKET NO. A-79-32 Geraldine V. Cox, Ph. D. Vice President and Technical Director Janet S. Matey Manager, Air Programs Edmund B. Frost Vice President and General Counsel David W. Carroll Assistant General Counsel April 6, 1981 \m - Chemical Manufacturers Association, Inc. 2501 M Street, N.W. Washington, D.C. 20037 (202) 887-1100 DO 067895 CONFTDFNTTAL YZ0028463 60.460(c) In earlier drafts to subject proposed regulations, a problem was surfaced with the definition of modification as set forth in 40 C 560.14 as it might apply to fugitive emissions. A concern was ex pressed that continuing small changes routinely made to a process unit made for a variety of reasons might subject the entire existing unit to the NSPS fugitive emissions requirements. The Agency's- pgfl 4an{/*)--satisfactorily resolveo thio earlier concern. w understand the Agencies' proposal in 60.480(c) to mean that process improvements, as defined in 60.481, costing up to 5 1/21 annually of the original investment in the affected SOCMI facility shall not by itself be considered a modification. This would satisfactorily resolve , our earlier concern. $60.481 -- "Closed Vent System". In discussions with EPA's OAQPS staff we were led to believe that the regulations would not prelude safety valve emergency releases to flaring systems or the atmosphere. In this regard, the preamble at page 1140 attempted to clarify that closed vent systems can be used to transport relief valve discharges and fugitive emissions to a controi device, such as a flare. The proposed regulations, however. OO 067896 CONF T OF NT I Al. YZ0028464 Iltll 1 oc These comments are also submitted on behalf of the Texas Chemical Council (TCC) whose offices are located at 1000 Brazos street, Austin, Texas 78701. The TCC is an association of 87 chemical companies having more than 67,000 employees and representing approximately 901 of the chemical industry in Texas, like the CMA, the TCC has also worked with the EPA over the past several years in i the furtherance of responsible environmental regulation. The TCC also ^ requests that the comments made by them which are referenced in Appendix A of the EPA's "VOC Fugitive Emissions in Synthetic Organic Chemicals Manufacturing Industry - Background Information for Proposed Standards" be incorporated as part of the administrative record in this matter. The comments we are submitting today make certain recommendations that attempt to clarify, and/or modify the Agency's proposed regulatory program to make technically more sound several substantive provisions, and to simplify procedures, recordkeeping, and reporting where the proposed requirements are either redundant, unnecessary, to demon strate compliance with applicable control requirements, and/or would reduce the paper workload. Nevertheless, we believe that the Agency has made significant . progress in addressing many of the concerns raised by CMA in our erlier submittals to the Agency on earlier drafts of the subject pro posal, and on various other Clean Air Act fugitive emissions programs. We believe, however, that additional modifications are still necessary in order to achieve a viable and reasonable technical fugitive emissions * .program.. n^7B97 is YZ0028465 3. -- < $60.481 -- "Fucitiv Saisaion Source." The definition of "fugitive emission source" includes compressors end pumps. Unfortunately the Agency has not included a definition as to the types of pumps and compressors not subject to the fugitive emissions NSPS requirements. As a result of this apparent oversight reciprocating pumps and compressors are included in the regulatory program. The potential problem we have with the inclusion of recip rocating pumps and compressors are their inability to accommodate double seals or any type of seel that EPA may utlimately raquire. Accordingly, we recommend that in order for EPA to avoid sealing problems associated with reciprocating pumps and compressors that such pumps and compressors be expressly excluded from the definition of "fugitive emission source." $60.482 (a) (1) - "dual mechanical seals" As we have commented on several times in the past, it is in. appropriate to require use of dual mechanical seals for pumps. We- r commend that EPA cease using the term "mechanical" and merely define the seals to be used in piuqps as dual seals. Such a modifi cation would provide industry with some flexibility for a source to us any properly designed dual saal. This modification would allow ' for the use of either pressure or level control devices. We compliment the Agency on adopting an equivalency regulation in $60,484 lb) that will allow companies to demonstrate the equivalence cf single seals whsre adequate and permanent monitoring will result in equivalent degree of controls. im 0 067898 C^FTDFNTTA( YZ0028466 -3 limit closed vent systems to transporting mergency r leas s to an enclosed combustion device or vapor recovery system. We are concerned that the clear language of the proposed regu lations contradicts statements made by EPA's OAQFS, the preamble, and various support documents that emergency releases can be transported by a closed vent system to not only an enclosed combustion device end vapor recovery system, as well as, a properly designed flare system, and other equivalent control devices. Failure to correct this inconsistency and revise the regulatory language could result in unanticipated enforcement initiatives based on the language of th proposed regulations. In addition, failure to revise the definition of closed vent system would arbitrarily exclude other control devices and properly designed flare systems which in many instances can achieve or approach the same degree of hydrocarbon reduction as en closed combustion devices or vapor recovery system at significantly lower costs. In order to clarify this matter we would recommend that the de finition of "closed vent system" be modified, as follows: "Closed Vent System" means a system which is not open to the atmosphere and which is composed of piping, connections, and, if necessary, flow in ducing devices that transport gas or vapor from a fugitive emission source to an inclosed combustion device, vapor recovery system, e properly designed flare system, or an equivalent control device as determined by $60,484. DO 067899 CONFTDFNT TAI In this regard we wish to reaffirm the position taken and made in the Texas Chemical Council's latter of 30 June 1980 to the EPA (comments on the Draft BID and Recommended SOCHI Standard) regarding flares and their use. YZ0028467 V -5in rder to remedy this in onsistency. As ve discuss d above, we believe that a closed vent system should to defined generally enough so that VOC fugitive emissions can be transported to appropriately designed enclosed combustion devices, vapor recovery systems, as well as, properly designed flare systems, or an equivalent control device* As presently drafted, fugitive missions from pumps would be initially precluded from being controlled toy catalytic combustion units unless a time consuming and costly equivalency demonstration can be made. Several of our member companies indicate that such control devices achieve equal or better control than the two systems presently recognized in $60.482(a)(3}(ii). To preclude catalytic combustion units without an adequate justification by EPA for requiring equivalency demonstration would have to be characterized as an arbritrary action. The comments set forth above are equally applicable to pumps fugitive emissions regulated under $60.462(a)7). We would hope that appropriate modifications consistent with a revised definition of closed vent system would be incorporated by EPA in the final version of S$60.482Ca) (3) (ii) and Ca) C7). $60.482 (a) (.6) - delayed compliance The proposed regulation requires that a leak. be repaired as s on as practicable, but not later than 15 days after its detected,'except as provided in $60*482 (h). The exception allows extensions only where the repair is technically infeasible without a complete or partial process unit shutdown. The extension, however, cannot exceed the process unit shutdown. The instant delay of conpliance provision significantly improves n earlier drafts which imposed arbitrary deadlines and meaningless reporting requirements. We, nev rth 1 ss, have s veral recommendations DO 067900 CONFIDENTIAL YZ0028468 It**' 60.462(a)(4) Liquid Leake This paragraph defines liquid dripping from a pump seal as a leak. However, the barrier fluid could be water so there would be no reason to repair a seal operated per 60.4B2(a) (3)(i) where the barrier fluid pressure is higher than the pump pressure so long as this higher pressure is maintained, we recommend that this paragraph be reworded to sayj "Each pump shall be checked by visual inspection each* calendar week for indications of liquids dripping from the pump seal. If indications of liquids dripping from the pump are seen, the vapor emissions shall be monitored .by the methods specified in 60.486. A vapor concentration greater than 200 ppm above background shall constitute a leak." 560.4B2 (a) (.3) Cii} and Qa) C?) ~ "residence time." In our review of this section we noticed an inconsistency between the proposed residence time and the technical data on residence time set forth at page 4-18 of the technical support document. See VOC Fugitive Emissions in Synthetic Organic Chemicals Manufacturing Industry - Background Information for Proposed Standards, EPA-450/3-80-033a, at 4-18 (November I960). An appropriate modifi cation of this requirement in the final regulations is necessary HHl on 067901 CONFTDFNTTA1 YZ0028469 1- special order end take up to one year f r delivery), and/or unforaeen manufacturers and/or delivery delays (e.g., strikes, fires, raw material delays in delivery). Any one or a combination of the above scenarios would result in the necessary replacement part(s) not b available until after the next scheduled shutdown. Since the proposed regulations would make continued operation after such a shutdown a violation of the Clean Air Act, we strongly recommend that a limited extension provision be incorporated by EPA into the regulations. We envision.placing the burden of requesting such a request upon industry by requiring a formal submittal to EPA in which the source would have to justify the need for the furth r delay in repair and the projected time frame for achieving complianc . We recommend that 560.482 (h) be amended to include the following regu latory language; "Delay of repair will be allowed beyond a process unit shutdown only where and for the period of time a source demonstrates to the satisfaction of the Regional Administrator or delegatee that repair of a leak by replacing physical equipment by replacing physical equipment exceeded the normal stock of spare parts and cannot be delivered until after the next shutdown, a special order of a part is required and cannot be delivered until after the next shutdown, and/or because of unforseen manu facturers and/or delivery delays, the replacement parts cannot be delivered until after the next shutdown." The consequences of not including such a provision in the final r gu- lations could r suit in unanticipated and costly c ntinuances f a shutdown until the repair parts are obtained, or in the exp sure ---------------------------- DO 06790? CONFIDENT TAI YZ0028470 -6- which would further clarify the regulati ns and more accurately re- fleet real world operations. First# we would recommend a definition of what situations qualify as technically infeasible in order to be accorded an extension after the initial 15 day compliance period. Such a clarification would minimize uncertainties and would reduce any unwarranted enforcement proceedings resulting where such an ambiguity in the regulations. Accordingly# we recommend that 560.482(h) be revised to include a definition of technical infeasibility# as followsi "For purposes of 560.482(h)# technically infeasible shall mean where a repair within 15 days of leak detection would constitute an unsafe practice, could result in premature total process failure, or could cause an unscheduled complete or partial process until shutdown." The second part of our recommendation on delayed compliance concerns th agency requirement that all repairs may not be delayed under any circumstances beyond a process unit shutdown. We concur that many* of the remaining delayed repair actions will be remedied during a shutdown where repair actions can not be technically of safety be conducted while the process unit is in operation. As the Agency is aware, most schedule shutdowns are on an annual basis or based upon operating performance of the process unit. As a result, there may be some limited instances where replacement of leaking equipment may not be available until after the shutdown is oompleted. Such instances include (but axe not all inclusive) abnormal near tens demands for replacement parts that exceed the quantity of replacement parts that ar normally maintained in stock and can not be replaced on short notice, the replacement parts/equipment are not off th shelf items and r quir long 1 ad time for deliv ry (i. some pumps require HO 067903 ________ CONFTDFNTTAl YZ0028471 -9~ the process unit would be greater than th missi ns from the fugitiv emission source(a)." we believe such a revision would remedy an unnecessarily narrow and environmentally counterproductive requirement. 560.482(b) - Compressor Standards. As a general comment, the comments, issues, and recommendations we raised on pump standards are generally equally applicable to com pressors. We do want to point out one inconsistency in the compressor standards which we believe should be clarified. In 560.482(b)(1) and (3) we are happy to note that the Agency only requires a seal system with certain characteristics be used for all compressors. This requirement would be consistent with our comment on 5560.482 Ca) (1) and (3) dealing with pumps, in which we objected to the Agency's requiring dual mechanical seals and not providing the necessary flexibility with a * dual seal system requirement. The inconsistency exists because the Agency at 560.482(b)(4) then reverts to referring to dual mechanical s al systems. Our substantive comments on 5560.482(b)(3)(ii) and (b) are reflected in our comments on SS60.482 (a)(3) (ii) and Ca) (2) above. Our substantive comments on 560.482 (b)05} and its interrelationship with 560.482(h) are reflected in our comments on 560.482(a)(6) above. Finally, our substantive comments on 560..482 (b)(8) are refl cted in our comments on 560.482 (a)(9) above. 560.482 (c)(5) - safety/relief valves in gas/vapor service. As proposed, the section requires each, safety/relief valve t r turn to emitting less than 200ppm above background after an amerg ncy pressure release no later than five calendar days after each epis de of pressure release. As proposed the regulation leaves a tremendous loophole which had to be an oversight. If a process unit is down five days after the release, it by definition will be in compliance. DO 067904 _ __________ _______________________________________ CONFIDENTIAL YZ0028472 8 to significant criminal and civil psnaltias for resuming peration without r pairing all leaks. We w uld consider it an arbitrary and capricious action of the Administrator to not provide such a remedy where the source has acted in good faith to repair all re maining leaks at the next scheduled shutdown# but solely because of uncontrollable events the necessary repair parts are not available. 560.482 (a) (9) - "Operation of Control Systems." This provision essentially requires that all existing proposed fugitive emission control systems be operated at all times VOC emissions may occur, we are concerned that a conservative and narrow reading of this provision will essentially preclude a process units operation where expected or.unexpected maintenance of the control system is required# or an emergency requires the control system to go down for repairs. It makes little sense to require the entire pro- c ss unit to shutdown where the control system has to go out of service for a short period of time to conduct maintenance and/or correct an emergency condition. In fact the start-up and shutdown of the process unit in most instances will probably result in greater emissions of VOC than if the process unit continued operation for the short period of time until the emission control system is back on line. We recommend that this provision be modified to essentially allow a by-pass of VOC emissions where the control systems must be taken out of service for maintenance or an emergency only where the net VOC emissions that will be bypassed would not exceed the excess emissions that would result from a shutdown and start-up of the process unit, we recommend that $60,482 (a) (9) be revised to added a second sentence# as follows: "A source# howev r# may bypass the applicable c ntrol device set f rth in $$60,482 (a) (3) UD and (iii) wher missions from an associated shutdown and startup of 1 HO 067905 C0NFIDFN1 IAI YZ0028473 ' $60.482(d)(2) be r v: id, as follow*! "(2) Each clos d purge system at required by 560.482(d)(1) shall return the purged proc tt fluid directly to the pr cess line, r shall collect the purged process fluid for recycle or disposal by means of a closed vent system." The technical support document does not support the proposed regu lations. Unless a modification is made, the Administrators actions must be characterised as arbitrary and capricious. S60.4B2(f)(2) - "definition of valve leak" The EPA has proposed 10,000 ppmv as the definition of a leak. In addition to being the same action level as set forth in the refinery CTG, we understand from a July 17, 1980, EPA meeting with the TCC that this particular level was also chosen because it is the top of the scale on the Century Volatile Organic Analyser. Apparently EPA felt 10,000 ppmv would make compliance easier for the chemical industry. We have some significant disagreements with these underlying assump tions. We believe a higher trigger level would achieve essentially the same control with much improved maintenance efficiency. The scale on the Century GC is a minor consideration, headings higher than 10,000 can be obtained readily with a dilution apparatus. In addition, we are confident that equipment manufacturers will be able to supply instruments with direct reading scales to whatever level we require. As the EPA has correctly pointed out, most of the leakage comes from only a few valves and the problem is to locate and repair thes . Based on the refinery data, about 981 of the emissions from valves in gas/vapor service will be from those having leak concentrations gr ater than 10,000 ppmv. Similarly, about 97% of the emissions will come from valves with screening values above 20,000 ppmv (Fig. 4-7A, EPA 600/2-79-044, "Emission Factors and Frequency of Leak Occurrence For Fittings in Befinery Process Units"), in s pr vious letter t % * ----------------- -------------------------------- - DO 067906 CONFIDENTTAL ------------------------ YZ0028474 We attune EPA means five calendar days from resumpti n f normal op ra tions after each episode of pressure release. We want to commend the Agency for establishing a performance standard for safety/relief valves in gas/vapor service rather than specifying inflexible design standards. We would encourage the Agency t rethink the proposed pump and compressor standards to establish a performance standard for pumps and compressors (i.e., 10,000ppm). It is our view that a performance standard is more a simplistic regulatory program to implement and provides necessary flexibility for sources to install the most cost-efficient and effective emission controls and pr cess systems. 560.462(d)(2) - sampling systems. As proposed the regulation limits the means of disposing of pr cess emissions. The proposal provides the option of returning the fluid directly to the process line/ or in the alternative, collecting the purged process fluid for recycle or disposal without VOC emissions to the atmosphere. This requirement amounts to a zero emissions require ment. As a fundamental concept the closed loop sampling system may be inappropriate or technically infeasible (i.e., low pressure process or tankage, safety requirements). Accordingly, this would require a collection system be used with no emission allowed. We note that no support for this premise is provided in the Agency's technical support document (see 4-22 to 23). In fact, the support document mentions that such fluids could be directed to a control device such as a properly d signed flare. In light of the lack of technical support for the proposed regulation, we recommend that the Agency include the uee of closed vent systems to minimize emissions from sampling systems. We recommend that j i j I ' i ; DO 067907 CONFIOFNTTAI I YZ0028475 "13560.482(f)(3) - "monitoring frequency* The pr posal ssentially requires that a monitoring program for^X * valves be on a monthly basis for leakers and quarterly basis for non- j leakers. We strongly endorse this proposal and caution against s retreating to mandating monthly monitoring. One rationale the Agency might consider for requiring monthly \ monitoring is a reliance on refinery fugitive emissions data where the \ Agency ultimately required monthly monitoring. The leak frequency data developed by EPA for the chemical industry are WOT similar to the refining data as EPA indicates on page 1141 of the proposal. The differences are summarised, as follows: Source Type Difference in leak frequency between SOCMI and refining _________________________________________________ data. ____ Valves "Gas service "Light liquid service "Heavy liquid service Similar SOCMI 50% of refining Similar Pumps "Light liquid "Beavy liquid SOCMI 33% pf refining Similar Compressors SOCMX>21% of refining Relief Valves SOCMI?45% of refining Process Drains Similar Flanges Bigher (Sf^Attachment B fc C for greater detail and discussion on this issue.) The above differences do not account for the fact that the chemical industry studies were conducted using a Century OVA-108 instrument calibrated on methane while the refining studies were con ducted using a Bacharach TLV instrument calibrated on hexane. Studies by Exxon Chemical (see Attachment D) on both instruments using both calibration gases show tha.t 29 percent more leaks are found using the 00 06790R CONTI OFNT T Al YZ0028476 -12the Agency, (s Attachment A) the TCC has shown that using a 20,000 ppmv action level versus 10,000 results in only 1% more emissions but r duces maintenance costs by 301. This factor is of major significance since Section 111 requires the Administrator to take into consideration the c st of achieving continuous emission reductions. In 560.48^(a) (4) (il) methane at 10,000 ppmv is specified as the calibration gas. This requirement differs from the refinery data on which most of the technical support is based where hexane was us d for this purpose. A study of the relative response of various gases with respect to methane and hexane indicates that a methane ealibrati n will, in effect, lower the trigger point to about B,000 ppm with the Century GC and even lower with the Bacharach TLV meter. This means more maintenance effort will be spent on valves with inconsequential leak rates. Recent data (Problem-Oriented Report, "frequency of Leak Occurrence for fittings in Synthetic Organic Chemical Plant Process Units", EPA, Sept. 1980, DCN 80-231-372-05-35, Data Listing Tor EPA Project #68-03-2776, Radian Corporation, December 19, 1980) from EPA's studies on leak occurence and recurrence in the SOGMI show a wide variability in repeat screening values for the same source. For example in Figure 4-3 of the Problem-Oriented Report^on the second day^values of approximately 2000, 6000 and 15000 were obtained from repeat measurements on the same valve. It is important that maintenance efforts be spent on the large leakers and not on the small ones since some data indicate that attempts to repair these only made matters worse. Thus the trigger point should be set high enough to insure isolating only the bad leak rs. For these reasons - maintenance efficiency, the effect of Methane calibration, and measurement variability, we again r commend that a leak b defin d at 560.482(f) (2) as 20,000 ppmv or greater. DO 067909 CONFIDENTIAL YZ0028477 -15TCC recommends using a lin ar le k recurrence rate with time in the , absence of data. Second the assumption that all the source types will * have a uniform recurrence rate (20% per year) is not a logical assump tion nor is it supported by the record. In the absence of data, a more logical assumption is that recurrence will vary in proportion to occurence. EPA, given the lack of data on valve leak recurrence and occurence with time, has structured a monitoring program for valves as gas/vapor and light liquid service which calls for monthly monitoring for leakers and quarterly monitoring for non-leakers. EPA states that straight monthly monitoring for all valves may be required if recurrence is found to be important. We submit that the existing chemical industry data shows initial occurence to be less (by 50% in the case of light liquid valves) than the the refinery data. Because of this differ nee, we recommend that EPA require the monthly monitoring scheme only f r those owner operators desiring to show equivalence demonstration. Since EPA has acknowledged that limited data are available on occurence/recurrence, we submit that EPA can only reserve the right to require more frequent monitoring whan the data are available from those owner operators desiring equivalence. 550.482(f)(4) - delayed compliance. Our substantive comments on this section and its interrelation ship with 560.482Ch] are reflected in our comments on 560.482(a)(6) above. 560.482 (f) (7) - Accessibility Exclusion. As we-reviewedeh.O'-pgepeaed megulatiena, wm-Moaeldled -an area dealing primaryJy with modified seusees that will be subject ee the new source performance .standards, tbit EPA apparently has eveel-eeked -tn-the-prepeaad regulations As'the-Agency is well award, at"cider | -facilities-many valves are not routinely accessible--because of safety _____________ _CONFIDENTIAL DO 067910 YZ0028478 -14Century calibrated on methane a* compared to the Bacharach calibrated on hexari . Thu* the 50CMI Data i* probably ev n let* than the re fining data a* thown above. Since the above data show initial leak occurence frequency within the chemical industry to be lets than the refining sector* we feel that EPA should require only true quarterly monitoring. We are of the pinion that the lower leak occurence frequency within SOCM1 w^ll more than offset the, admittedly, unknown effects of leak recurrence. EPA has offerred as a reason for possibly requiring monthly monitoring to be the potential importance of leak recurrence between valve monitoring intervals. This analysis was performed without the benefit of review of EPA's chemical industry valve maintenance study which may provide further information on the importance of valve leak recurrence. The above conclusions are discussed in further detail below and in the attachments. The EPA continues to base occurence and recurrence leak rate assumptions on Table 4-2 from the final technical support document (copy attached as Attachment E) which is the same as taken from the draft technical support document. The Texas Chemical Council (TCC) commented on the issue of occurence/recurrence in comments submitted to EPA in June of 1980. These comments have not been addressed by EPA and cannot be ignored. We wish to emphasize the points rais d in TCC1 s comments on this issue are still valid. In addition to TCC's earlier comments, we offer the following additional comments. First, EPA's assumption of non linear leak recurrence with time is not based on any data but rather an "engineering judgment". The assumption that twice as many leaks will be found annually as c npared to quarterly and twice as. many leaks will be found quarterly as compared to monthly is sinply not 1 gical and is n t supported by the record. ___ _____________ _______ DO 0679] 1 conftofntiai ` YZ0028479 TZ~g As the Agency is well aware, in existing facilities many valves are not routinely accessible because of elevation cr because access to the valve bonnet is restricted, etc. Most, if not all of these, can be eliminated in an entirely new plant. But they become a problem in an older plant that becomes subject to this regulation because of modification. To correct these problems, we propose valves that are inaccessible for safety reasons and that valves that are inaccessible for other r asons in modified sources be excluded from the requirement of 60.482(f)(1)--(6) but subject to the new 60.482(f)(7)-(8)- Accordingly, we recommend that the new 60.482(f)(7) and 60.482(f)(8) be added as follows: "(7)(i) An owner or operator of a new or modified source subject to the requirements of 60.482(f)(1)--(6) may for valves that are routinely inaccessible for safety reasons monitor each inaccessible valve for lealcs after a process unit overhaul prior to startup by pressuring with nitrogen to the system process pressure or 100 psig, whichever is less, and checking with a soap solution for bubbles, or other equivalent test method pursuant to 60.484." "(ii) When a leak is detected, it shall be repaired as soon as practicable, but no later than the next scheduled shutdown, or consistent with 60.482(h)." "(iii) For purposes of 483 or 484, inaccessible valves shall not be included." D0 06791? CONFTOFNTTAl I l YZ0028480 -16- cor.s-ideracions. 7" V / We propose that valves, at modified facilities subject to these ` *. / requirementsthat are inaccessible for safety reasons be excluded from the requirements of $560,482 tf) (1)-(6) but subject to a new 560.482(f) (7). This--new provision would only apply to modified `V / sources and not apply to new facilities. Accordingly, We recommend that a new $60,482 (f) (7) be'added, as follows; / "(i) An owner or operator of a modified source subject to the requirements of 5$60.482.,() (l)-(6), may for valves, that are routinely inacessible for safety reasons, monitor each inaccessible vale for leaks after a process unit/overhaul prior to start-up by pressuring with nitrogen the system process pressure, or 100 psi, whichever is less, and checking with a soap solution for bubbles, or other equivalent test methods pursuant to $60,484." "UD When a leak is detected, it shall be repaired as soon as practical^; but no later than the next scheduled shutdowr^or consistent with 560.482 (h). "(iii) Forjpefposes of $$483 or 484, inaccessible v valves^airfil not be included." As we reviewed the proposed regulations, we identified an area which the EPA has apparently overlooked in the proposed regulations. This area is inaccessible valves. These fall into two general categories, valves inaccessible for safety reasons and valves inaccessible because of elevation and/or configuration. Certain chemical processes are carried out at such extreme conditions of temperature or pressure, or the chemicals themselves are so unstable or hazardous that the operation is done behind barricades and the like, and, for safety reasons, personnel are not allowed in these areas while the unit is in operation. DO 067913 OONFTDFNTT Al i m YZ0028481 17- emissions. If properly implement d we believe this concept will provide a source the necessary flexibility t adopt a control program ' that is the most cost-effective for a specific site. In many in stances a company will now be able to either Implement the valve standards contained in $60.482(f) or adopt a alternative percentage valve approach that more appropriately can be implemented at a site. We recommend that the Agency retain this concept and needed flexibility in the final regulations. Although we wholeheartedly support this concept, we have a few comments and questions, that need clarification by EPA, in order to improve upon the proposed alternative standard. One matter we believe needs clarification is the criteria the Administrator will use in either approving or disapproving the re quest for an alternative standard as set forth in $60,483 (a)(5). We are unclear if the criteria are set forth in only $$60.483(a) (1) and (2), or in $$60.483(a)(l^(4). Or in the alternative, are there other conditions and criteria not set forth in the proposal that the Administrator might consider/use in approving or disapproving the use of the alternative standard. We believe the Agency has a duty to clearly set out all the criteria it proposes to consider, the basis for each criteria, and limit approval/disapproval activiti s to this list of criteria. i In our discussion above concerning accessibility of valv s, w Arru' A* indicated that for certain^modified facilities subject to thes requirements, it was infeasible for safety reasons to subject 11 the valves to the provisions of $60.482CX). Should a facility s ek an alternative standard pursuant to $60.483Cal, the accessibility of certain valves would create a problem in calculatin a meaningful allowable pare ntage f leaking valves. We recommend that these | valves not be included as part f th alternative program and be DO 067914 CONFIDFNT TAI YZ0028482 " (8)(i) An owner or operator of a modified source subject to th requirements of 60.482(f)(l)-(6) may for valves that are routinely inaccessible because of elevation or configuration monitor each inaccessible valve annually using test methods pursuant to 60.485 or a soap solution for bubbles." "(ii) When a leak is detected, it shall be repaired as soon as practicable, but no later than the next scheduled shutdown, or consistent with 60.482(h)." "(iii) For purposes of 483 or 484, inaccessible valves shall not L be included." 560.482 (g) (2) - delayed compliance. Our substantive comments on this section and its interrela tionship with 60.482 Chi are reflected in our comments on 60.432 (a) (6) above. 60.482(h) - delay of repair Our substantive corrnents on this section ere set forth in de tail in our comments on 60.482Ca)(61 above. 60,483 - alternative standards - percentage of valves leading **) The proposed alternative standard for valves in gas/vapor and valves in light liquid service establishes ar. allowable percentage of valves leaking approach fcr ascertaining compliance. As we have recommended in earlier submissions to the Agency, the chemical industry wholeheartedly supports the concept of using allowable per centages cf valves leaking as a vehicle fcr regulating fugitive DO 067915 CONFTDFNTTAl YZ0028483 -19 New 5560.483(a)(7) end (b)(5) should be added, es follows* "An owner or op rator may terminate complying with an alternate standard, by writing the Administrat r informing of this decision and immediately complying with the requirements of $60.482(f)." 460.483-<M-*g'' Alternate Worh-Praotloes- wi el hi wc it 11 be e is le b Pi mi fe ll mi PI C< Pt UI is ar Ii ui i 00 067916 conftdfntiai YZ0028484 -18. * regulat d pursuant to our proposed 560.482(f)(7). This s lution would require a modified source applying for an alternative standard to clearly identify in the $60.483(a)(2)(iii) data those valves that will remain subject to $60.482(f)(7). In determining compliance with the proposed $60,482 requir merits, EFA clearly sets out a $60,482 (i) the standard to be used in deter mining compliance. No similar provision exists for either $$60,483 (a) or (b). We are uncertain what, if anything, triggers a violation of the clean Air Act. Or does the Agency mean, if you fail the test - set forth in $60.483(a) (4), the provisions of proposed $60,482 are reinstituted? In order to make $60,483 enforceable, we recommend that a provision similar to $60.482ti) be added that sets forth the vehicle for the regulatory agencies measuring compliance with $60.483,as follows: "(c) Compliance with $60,483 (a) in this sub part shall be determined by the performance test set forth in 560.483(a)(4). Compliance with $60.483(b) in this`subpart shall be determined by review of records and in spection ." Another area of uncertainty concerns a sources ability to formally switch from an approved alternative standard back to the requirements set forth in $60.482(f). For a variety of reasons, at a point in time it may no longer be cost-effective for a source to comply with a $60,483 alternative standard, we recommend that EPA accord these sources the flexibility and ability to switch back to the $60.482(f) valve standards, after notifying the Administrator in writing that they no longer wish to be subject to an approved alternative standard, and will comply with the 560.482(f) standards. S L DO 067917 CONFTDFNTTAl YZ0028485 21 percentabe^of valve* leaking under $60,483 fal C31 * The advanfcfrg^* of the quality control approachadyoctf^ed here is that: (1) greater emisfci^n reduction* wil^he^fealized industry-wide because there is an incentive^Q;;^tf'*o7 C21 the monitoring burden will be lessened oniow^Ieak plant*fendsincreased on high leak ones, and (3) w<*H**tSefined rule* on what can and cannot be done will be to the owner at the design stage. 60.483(c) - Good Performance Incentive Although we believe 60.483(b) is intended to provide industry with the flexibility they need to carry out this program most efficiently, the present wording of some provisions will greatly inhibit it* use. In 60.483(b)(3) optional work practice programs must show a percentage of valves leaking that is equal to or less than that under the 60.482(f) program. Taken literally this would rule out any statistical or probability bated inspection system in new plants if they provide the best leak prevention options in their original design. The time to assure a low-leakage plant is when it is being designed and built. Quality control experience shows that quality must be designed into a product; it cannot be inspected in. But the owner needs some incentive to put in more expensive high performance equipment. In establishing a fixed-period, 100* monitoring program the EPA has provided no incentive to reduce emissions by quipment design since the better a plant is controlled and engineered initially, the less chance there is to reduce monitoring through an alternate work practice. In fact, the required monitoring program does not directly address the real problem of preventing leakage which can be drastically affected by valve and packing selection. This is unfortunate. The regulation should encourage the owner to put in the best leak prevention options available. oo 0*791* c,o^ 1 YZ0028486 -20 iftlity control experi nee shows that quality must be designee into a product; it cannot be inspected in. Thus the tine to asamre a low leakage plant is when it is being designed and built. Buj: the owner needs\some incentive to put in more expensive high performance quipment. I\establishing a fixed-period, 100 percent gfonitoring program, the EPikhas provided no incentive to reduce qibissions by equipment design s^nce the better a plant is controp/ied and engin red initially, the less bhance there is to reduce mojjftoring through an alternate work practice. In fact, the required^monitoring program does not directly address the\eal problem of preventing leakage which can be drastically affected by b^lve and packing selection. What is needed is some "good performance lav&l" which, designed to and met, would result in reduced monitoring requirements. Snee and Xittleman of E. I. dW Pont de Nemours & Company pr sented a paper describing statistical inspection plans for monitoring fugitiv emissions from leaking valves on^(pril\e-17, 1980, to the National Air Pollution Control Technique^ AdvisorACommittee and then followed this up with a second paper (fetter front T.\A. Xittleman (Du Pont) to Glynda E. Willins (Radian Corporation), November 13, 1980) on choosing a good performance level. / These papers provide^ sound technical base for both statistical inspection plans and performance levels. They show that the required^inspection program results iihessentially a two percent of valves le/king based on the technical support document model plant examples. It seems reasonable then to allows, operators to adopt inspection/plans that will assure a two percent leakage rate within a plus/or minus ten percent variation. We reotHnmend that 960.483(b)(3) have added to it a second\ paragraphsstating - "(ii) Owners or operators may commit to an rnspection program that will' ssure a two percent of valv s leaking within a ten percent plus or minus variation without determining thaV YZ0028487 We reconun nd that the EPA include a third alternative as follows: 4 "60.483(c) Valves in gas/vapor and valves in light liquid service good performance incentive. (1) Owners or operators may commit to an insepction plan which allows annual inspection after not more than 2% leaks are detected in five successive quarters. (2) Inpsection requirements under 60.482(f)(1) and (3) are reinstated whenever the 21 good performance level is exceeded. (3) All leaks found will be repaired and inspected monthly until repair effectiveness is demonstrated in two successive months. (4) Any other inspection plan will be allowed by the Administrator if it can be shown to be equivalent to 60.483 (c)(1).(2), and (3)." The advantages of the quality control approach advocated here is that: (1) greater emission reductions will be realized industry-wide because there is an incentive to do so, (2) the monitoring burden will be lessened on low-leak plants and increased on high-leak ones, and (3) well defined rules on what can and cannot be done will be available to the owner at the design stage. DO 067970 CONFTDFNT T Al.. YZ0028488 */a. A manor incentive would be less inspection for low-leak plants. This makes sense; low-leak plants should require less inspection, highleak plants more. Quality control inspection plans provide this option while at the same time including a check for deterioration in performance which, when detected, results in the requirement to return to more frequent inspection. But before these plans can be used some means of rewarding, rather than penalising, those who build low-leak plants must be provided, what is needed is some "good performance level" which, if designed to and met, would result in reduced monitoring requirements. Snee and Kittleman of Du Pont presented a paper describing statistical inspection plans for monitoring fugitive emissions from leaking valves on April 16-17, 1980 to the National Air Pollution Control Technique Advisory committee and then followed this, up with a second paper (Letter from T. A. Kittleman, Du Pont, to Glynda E. willins, Radian Corporation, November 13, 1980) on choosing a good performance level. These papers provide a sound technical base for both statictical inspection plans and performance levels. They show that a good performance level of 21 leaks is equivalent to EPA's BID basis used to estimate the leak reduction effectiveness of EPA's proposed regulation. It seems reasonable then to allow operators to adopt inspection plans that will assure a 21 leakage rate will not be exceeded. , In their papers Snee and Kittleman illustrated the use of a skip-period monitoring concept with a plan which would be widely used for monitoring fugitive emissions. Skip-period inspection plans have been used to inspect the quality of manufactured products for more than 25 years. These plans are widely used throughout industry and have a solid mathematical and statistical basis. Their proposed plan calls for five successive quarters of good performance to be followed by yearly inspection as long as good performance is continued to be demonstrated. If the specified level of good performance is exceeded, then the plant must return to quarterly inspection. Any leaks found must be repaired and monitored until the repair effectiveness has been demonstrated for two consecutive months. The proposed regulation should be amended to provide for the use of this, r any equivalent, alternative. 00 0^7971 CONFTDFNTTAl YZ0028489 -22a m ana of btaining an equivalency deteminati n of alternative teat method a and procedur a. We recommend that a new $60,485 (c) be added 4 that authorizes seeking equivalency determinations of test methods and procedures and seta forth the criteria the Agency will use in evaluating an equivalency application. (The procedure would mirror that set forth in $60,484 for equivalence of alternative means of emission limitation. S60.486 (c) - Recordkeeping Requirements This subsection requires that various technical data dealing with detailed schematics, structural designs, and design specifications shall be kept in a log, that is r-adily accessible, ostensibly at the site. We have no reservations about making this data/information available upon a reasonable request of EPA. We do, however, have reservations about being required to collect all this data and hous it in one location. As a matter of corporate operations much of this information/data are not always kept together, nor are they needed to be kept together for purposes of assuring and/or demonstrating compli ance with the fugitive emission standards. . As the Agency is well aware, the Agency under Section 114 has the authority to require a source to "establish and maintain such re cords" in order to determine whether .a person is complying with any standard under Section 111, or carrying out any provision of the Act. The Agency has not demonstrated how the required reports are necessary to ascertain and/or carry out Section 111 of the Clean Air Act. Further, th Agency has not demonstrated why all the proposed information must be kept in a readily accessible location when industry indicates it will make such data available upon request by EPA. We believe the pro visions in $60.486Cc) as proposed exceed the authority vested und r Section 114 to the Administrator, and imposes an arbitrary capricious requirement unless modify to reflect industry's willingn ss DO 0679?? CONFTDFNTTAl YZ0028490 3J C *> 560.484(b)(1) - Equivalence Determination As proposed 560,484Cb) Cl), limits applying for an equivalence determination for an alternative means of emission limitations to th wner or operator of a facility. We are concerned that this artifical limitation may limit the incentive for or ability to use innovative technology. We believe that the manufacturers and/or vendors of new and/or innovative technology should also be authorized to apply for an equivalence determination. In a real world-context few companies are going to purchase such a system unless the manufacturer and/or vendor will state that EPA has essentially approved the system. Accordingly, if EPA truly desires to encourage the use of innovativ technology, it should authorize the manufacturers and/or vendors to also request equivalency determinations. We recommend that the first line of $60,484 Cb) Cl) be modified, as follows: "Cl) Each facility owner or operator, a manufacturer, or a vendor applying ..." 560.485 - Test Methods and Procedures The test methods and procedures set forth in the proposed regu lations are essentially based on the state of technology as of this date. We are concerned that the regulations do not 'rovidt the necessary flexibility to approve in the future the use of new instru. ments that may use different calibration systems which provide equiva lent or more accurate results. We believe the regulations must provide DO 06?9?3 CONFIDENT TAl z YZ0028491 -24- data for EPA should EPA want this data, they can ithax request it in writing directly from the source or review it at the facility. As 4 the Agency is well aware, ease of enforcement is not a legitimate grounds for requesting the reporting of data/information unless it is also necessary for purposes of determining compliance. As will be noted below, this data/information also duplicates data/information that must be reported under $60.487(b). The duplication of data/information should be avoided by EPA as much as possible. We recommend that $60.487{a) be deleted. As to the specific information required under $60.467(b) we hav the following comments. As a general point, we are only commenting on the specific information requested on in $60.487(b) since the Agency has indicated that the forms and data requested therein are not requirements of the proposed standards. If, however, the Agency changes its mind on this issue, we reserve our right to subsequently submit comments on the example forms on pages 1158 and 1159. The leakless valve data requested in $60.487(b)(2) is irrelevant for purposes of determining compliance with $60*482 (f)(6). It is irrelevant the number of leakless seals that exist at a specific pro cess unit. Accordingly, $60.487(b)(2) should be deleted* The data requested in S60.4B7 (b) (4) is irrelevant for purposes of determining compliance with $60.482(f). Compliance can be deter mined adequately by evaluating the data submitted as required by $560.487(B)(3)(5) and (6). Accordingly, $60,487 (b)(4) should be deleted. In both $60.487(b) (7) and (8) the Agency has not requested the critical point of whether or not the pump/compressor leak was repaired similar to $$60.487(b)(5) and (6). If the Agency wants truly meaning ful data it should consider adding a new provision that would requir | this data. s no CONFTOFNTTAl YZ0028492 -23 to make'the applicabl ,d ta vailable upon request. In this regard, we recommend that $60.4B6(c) be revised as follows: "(c) The following informstion pertaining to the design requirements for closed vent systems, enclosed combution devices, and vapor recovery systems required in $$60.482(a) and (b) shall be recorded and made available upon request by the Regional Administrator or delegate: (1) Detailed schematics, design specifications, and piping and instrumentation diagrams. (2) The dates and descriptions of any changes in the design specifications. (3) Periods when the enclosed combustion devices and vapor recovery systems required in $$60.462(a)and (b) are not functioning as designed and dates of start ups and shutdowns. $60.487 - Reporting Requirements The requirements proposed in $60,487 set forth the detailed r - porting requirements a source must make to the Administrator on ' quarterly basis. As we commented above, the Administrator may require an owner or operator of an emission source, persuant to Section 114 to make reports where the information to be reported is relevant to ne of the purposes set forth in Section 114(a). In this regard, the r porting requirements set out in $60,487 must be relevant to deter mining whether a person is in violation of one of the standards, or for carrying out any provision of the Act. The Agency sets forth that the subject reporting is solely for the purpose of determining compliance with the NSPS. Accordingly, where the data/information requested is not relevant to ascertain a services compliance, the Agency will have exceeded ite authority under Section 114 to require the reporting of such data/information. Under S6Q.487(a), it is unclear what a "summary" of the recorded data/information in $60.486 0b) would entail. Since this data must be r adily accessible by the source, it seems unreasonable merely for ease of enforc ment purposes to r quir a source to summaris this 00 067925 CONFTDFNTTA tlttl 26 (8) R asons for n n-repair of pumps and/or cotnpraasors within 15 daya aa r quired in SS60.482 (a) (6) and/or (b)(5). (9) Number of pumps, compressors, and/or valves not repaired pursuant to the de layed compliance tine achedule of $60.482(h). (10) Statement signed by the owner or operator stating whether all provisions of 40 CFR 60 Subpart W had been fulfilled during the reporting quarter. (b) The provisions of $60.8(d) do not apply to affected facilities subject to the provisions of this subpart. (c) In the first report submitted as required in $$60.487(a), the report shall include a reporting schedule stating the months that quarterly reports shall be submitted. Subsequent reports shall be submitted according to that schedule unless a revised schedule has been submitted in a previous quarterly report. C nclusion Although the Agency has made substantial progress in addressing the numerous issues the chemical industry has raised on earlier drafts of the proposed fugitive emissions NSPS, we still have several reservations with the subject proposal. We still have reservations as to the inflexibility of several of the proposed requirements and it still is procedurally more burdensome than necessary for sourc s to expeditiously and cost-effectively identify and repair fugitive emissions. In this regard, CMA has presented several recommendations in these comments which we believe would further clarify and make more flexible the fugitive emissions NSPS program. We urge EFA to giv serious consideration to the CMA proposals and modify the proposed regulations to reflect the concerns expressed herein. DO 067926 CONFTOFIMT TAI YZ0028494 -25- As we discussed earlier, delay d compliance may in some instances occur after the fifteen day period after leak detection (i.a., next scheduled shutdown) or in a few limited instances by necessity after the next scheduled shutdown (i.e., CMA recommended regulatory language for discretionary extensions after the next scheduled shutdown). In order for SPA to have meaningful data to accurately appraise a sources compliance status new provisions should be added to ascertain the number of pumps, compressors, and valves not repaired by the next scheduled shutdown, and the number of valves, pumps, and compress rs not repaired consistent with a time schedule approved by the Regional Administrator after the next scheduled shutdown.* We recommend that 560.487(a) be revised, as follows! 560.487 Reporting requirements. Each Owner or operator subject to the provisions of this subpart shall comply with the following reporting requirements. (a) Quarterly reports shall include the following information: (1) Process unit identification. (2) Number of valves for which leaks were detected by the monitoring method specified in 560.485(a) during each month of the reporting quarter. (3) Number of valves not repaired within 15 days as required in 560.482(f)(4). (4) Reasons for non-repair of valves within 15 days as required in 560.482 (f)(4). (5) Number of pumps for which leaks were detected during the reporting quarters as specified in 5560.482(a)(4) and (a) (5). (6) Number of compressors for which leaks were detected during the reporting quarter as specified in 560.482 (b)(4). (7) Number of pumps and/or compressors not repaired within 15 days as required in 5560.482(a)(6J and/or (b)(5). DO 067927 CONFIDENTIAL YZ0028495 I April 6, 1981 CCi (TO BE ADDED LATER] --27 Respectfully submitted, Edmund B. Frost General Counsel and Vice President Geraldine V. Cox, Ph. D. David W. Carroll, Esquire Janet S. Matey Chemical Manufacturers Association 2501 M Street, N.W. Washington, D.C. 20037 (202) 887-1100 DO 0679?8 c onf s s YZ0028496 V|. SI? No. 16 CORRESPONDENCE 1027 loop-terra mrvival among patients with Stage III disease n 25 perceal (two of tight). Among patient* with Stage IV di*ca*t, 6 of 34 (IS percent) have turvived overall; oT the 23 patient* with bone metMUii* and bone marrow involvement at diagnosis -- a group generally coniidered to have a particularly poor prognoaia, S (22 percent) have aurvived. The aurvival of theae five patient* indicate* that marrow 'purging" may not a(way* be needed. There ha* been a price (or turvival -- considerable treatmentrelated chronic toxicity. Six of the eight children have auditory injury affecting their hearing range' and wear hearing aidi. Five patient* have reduced glomerular filtration rate*,* two of whom have chronic renal failure; one of them require* antihypertenaive therapy. Apart from theae handicap*, the eight children (now 6.3 to 12.4 year* old; median, 8.2) are leading full and active live*, includ ing normal tchool attendance. Tbit aerie* i* relatively mall, but a comparable rate (71 percent) of response to (hit chemotherapeutic regimen ptui surgery hat been observed in a larger etudy by the European Neuroblastoma Study Group.5 Previous reports state or imply that no progress ha* been made over the past.10 yean in treating advanced neurohlaitoma and that the number of survivor* who are more than one year old ar diagnosis is negligible.*-' We challenge these assertions. Our experi ence >uggett* that the median nnvival of patient* in Siege III and IV ha* been extended. High-dose mdphalan is probably an impor tant component or this improved prognosis1; therefore, the long term result* at center* using more intensive "consolidation" regimen**'15 will be awaited with great interest. Rather than adopt a negative attitude, thoie treating children with neurohlaitoma should energetically search for better induction and contolidatlon regimen* *0 that reaponte rate* can be improved. London, WC IN 3JH, United Kingdom J, ParrcHAsm, E. Kiclv, D.W. Rooaaa, L. Srrrr, E.A. Sttanono, R. Bmmton, C. Mull**, and V.M. Wasoter Hospital lor Skit Children 1. Bvms AE, D'AagioGl. Randolph I. A proposed tt*|iig far dUttca with mwHtrtma*. Omrar 1471; I7J74-I. 2. Shsfford EA, Roytn DW, Pnachaid I. Adrsocad Marobiamxs*: toftovsd rasponrr net nsiag * nxiltisgeot nfiaen (OPEC) imtading sequential citnluta and VM-26. J CUa Oncol 1444:2:742-7. 3. McHuey VA, TMbadoux O, Haysl FA. Oms* AA. Htariag lost in diUd* receiving cisptsdn chemothnapy. J Mins 1943:102:314-7. 4. Werner RB. PiiKbtrdJ, Banco TM.Reaal toxicity of clspktio in ehlldkm. IPoAttr tm 106*39-63. 3. Midurdl,GtnDoodS.JoocsD.<leltnkerJ.U>*eS.bhi|hdoieMelptiabo (HUM) oT value ia neanmw of odvaoetd reuroWamnns (AN)? Preatiosiy mulls of rrodmiatf Mat by the Earapcan NtuNbltMomt Study Ora? (ENSO). hoc Am toe Clin Oncol 1946; 3:203. abstract. 6. Ormfsldl. NeurehlHoaia-Hiy* DM, od. In: Podbnicautgicil oncology. Ortsodo, Hi.: Oruoc A gurnet). 1(46; 43-43. 7. Vows PA, ds Kraker I. botysn iMV. Tumors <4 the lympaiUtk aerraus lynetn: ocaroUaMma, ga^lkneoreraa and phmctuxxnoeywm*. la: VoW* PA. Burnt A. Blown RIO, Lcmtxk J. Hrirthmi MK, od*. Caorer to ddMrae: clinks] awoogenkM. 2nd od. Berlin: Spnogw-Vniu, 1916: 234-31. I. AaguOC3.3sroWFT. Koch PA. a si. Tirkmmtof odvaacod miAlto- an wiM supnlnhal chemotherapy- wdbdoo. md sllofcoclc or mMlo|ou* MWiow mmutimtioa. J Clla Oacol 1914; 2*09-14. 9. Hwtnaao O, Kalifi C, Bc*c)e** F. Style C. Senhisnen E. Lewie J. Throws* of odvaooad ncuraMtuom* wldi two coawculivo hlgh-doee durottanpi icgiim and autotogous bon* mumw tzafishuion. to; Evans AE. D'Aagio OJ, Scepcr RC, edt. Advances in imuohlanoma neesrch New Yost Aba R Lbt. 1943*63-4. 10. fhUlp T, Eton P. PhtiUp I, M tl. AWotofou* bone murew tnaaptaautioe tor very bod riTO noumbhalons. In; Evans AE. D'Asgio Cl, Socgn RC, tdt. Advances in newobbiloma seteweh New YoA: Alan R. List. 1943:469-16. AIDS AND RENAL FAILURE 7b Mr Eritsr: Rao et *1. observed accelerated wasting and early death tn patients with the acquired immunodeficiency syndrome (AIDS) who requited maintenance hemodialysis tor therapy of endstage renal disease (April 23 issue).1 The course appears to be more rapid than ha* been observed in patients with AIDS who do not have renal failure. This observation may indicate that patients with renal involvement have more extensive human immunodeficiency virus-related disease and therefore die sooner. However, h is also passible that hemodialysis accelerates the progression of AIDfi. Normal immune stimulation of T helper cells may trigger replica tion of the AIDS virus.' Furthermore, patient* receiving mainte nance hemodialysis have an increased proportion of activated T cell* in peripheral blood, as defined by expression of Interleutin-2 receptors.1 Whether such activation of T cells reflect* long term exposure to blood transfusions, infectious agents, nr dialysis membrane* or tubing, or la a manifestation of the uremic state itself, it unknown. Intravenous drag use, present in a high proportion of the patients studied by Rao et al., would also be associated with chronic immune stimulation. It might be interesting to see whether patients on long-term ambulatory peritoneal dialysis have increases m immune activation of T lymphocytes comparable to the Increase* observed in patients on maintenance hemodialysis. If increased Teell activation is more marked in maintenance hemodialysis than in other forms of therapy of end-stage renal disease, survival of pa tients with this disorder and AIDS could be ctihanced byan alterna tive therapy (such as long-term ambulatory dialysis, if feasible). Philadelphia, FA 19104 Atax Waxscmtum, M.D. Cabolyn Killy, M.D. Univenity of Pennsylvania School of Medicine I. Rao TICS, Friodaun EA, Nicaroi AD. The types of ratal djststs la 4w acquired Imawnmlifiasncy syndrome. N Engl J Med 1917; 316:1062-4. 1. NsbalO, EahlraoreD. AndacMebsntcripdo* factorscivNrasiyfcra of luroan bnnmtodelcicncy vfora In T nib. Nome 1947; 326:711-3. 3. raroianull rniraf Tti--'art flrl P~....... r~s_nt"SlrlTTTnTt- bnaodtslyrad patitaii: Weir possible ids in skend immunity, free Natl Acad Id USA 1(46; 43:7437-41. _ .. .. BENZENE AND LEUKEMIA . 7k Mr Atvr. In the study on bensene and leukenda by Riusky et al. (April 23 issue),* there were but nine cites of leukemia and four enact of myeloma. Theae are very small number* on which to base conclusions, especially when the overall mortality has been as expected and the mortality due to malignant neoplasms has also been ns expected. . Of special interest is the authors* Table 4, which Ustt the cases. Some had minuscule exposure, and one wonders what other malig nant disease-causing agents Ibeyjnay have been exposed to during their live*. Of special interest is the foci that no employee fitat exposed after 1954 had leukemia or myeloma, even though hiring continued for II yean and even though 7 of the 13 case* had the onset of disease within 20 yean of first exposure, (Case* were fol lowed through 1981, so there should have been some cases.) In the study, two subjects died within 316 years of exposure. Looking at the year of knitia) exposure of the 13 cases, one can see that 9 bad first exposures before the end of World War II. One wonders about tbe'meaauring instruments in that situation. Having spent same time Studying childhood malignant disease more than 23 years ago, I am very sensitive to the tendency to observe dusters of cates sometimes living within short distances of each other. Statisticians have generally attributed theae to chance, and there is no reason why that may not be true in the cases in this tody. Seatde, WA 98113 Max Baoca, M.D., M.P.H. 6536 29th Ave. NE *Rlesky RA. laiiW AB, Honumc R. si si. Bchcm rod letiksnds: sa spMWiiiokffc risk sssesfraeaL N ErfIJ X4s4 1967; 116:1044-50. 7k 4b EdUtr: The paper by Rintky et al. on workers in rubber hydrochloride plants exjxned to benacne repons a cohort study, a ease control study, and n risk assessment for leukemia in relation to benzene. Table 1, which uses data foom that paper, indicates a discrepancy between the cohort and case-control studies. The case- 00 0679? 9 CONFJopNj TAI YZ0027906 1028 THE NEW ENGLAND JOURNAL OF MEDICINE *t Oct. IS, 1987 Table 1. Death* from Leukemia, the Standardized Modality Ratio (SMR). and the Predicted Odds Ratio, According to Cumgtutvu Exposure to Benzene. Cvhoutivi Enemas Bum non Ltuuw* Omdveo a nuertia OhsRaiw* <M0 40-200 200-400 >400 2 l.t 1.3 2 3.2 4.3 2 11.9 43.1 9 66 423 ftan Sit Ibt Mill--I IBM *f aiUy tt at., uis) ec ntau or Kt e^MUM CWftiy MM un-yam fer N|S*u anally). control risk luctrmcnt ptedieu, in the highcr-exp04ure categories, odd* ratio* much larger than the itandardiaed mortality ratio* ob served in the cohort. A possible explanation for the discrepancy is that the exposure of the contrail wai much lower than that of all cohort members without disease. In support of this, it can be in ferred from the paper that the mean cumulative levels'of benzene exposure of the 1156 autgecta without diseaic and the 90 ccntrpl* were about 67 and SO parts per million (ppm)-yean, respectively. It il reasonable to a*k why the case-control study wa* done. A case-control study within a cohort is usually done to reduce the cost of determining the exposure of all cohort members without diseaseHowevtr, this reason is not applicable here, since the exposure to ist.benzene of all cohort members was known. Rinsky et offer sever al rtaaona for doing the case-cootral study, but all the objectives could have been met effectively by a cohort analysis of all the data. The disparity between the mean exposure level of all cohort members without disease (67 ppm-yeata) and that of the 90 oootrals (50 ppnt-yeart) requires explanation. It is probably not the result of selection due to matching, since this should have raised the level in the comparison series. The investigators may have reviewed the information on the benzene exposures of cases and controls, with foe result that the average level of the contrail, but not that of the cases, was lowered. If such u review explain* why the control expolure levels were lowered by 26 percent, then the validity of the cohort study i* questionable. Finally, IT chance explain* the differ ence between the cohort data and the case control risk aiscument, a risk siictiment based on the entire cohort would be superior. Irrespective of the explanation, it would be appropriate to evaluate the data further. Although (hit might involve reevaluation of the benzene exposures of all cohort members, tbc remits should clarify the relation between benzene and leukemia. The Occupational Safety and Health Administration (OSHA) proposes to reduce the benzene standard of a 10 ppm time-weighted average to I ppm. A principal basis for this is the results of the rubber hydrochloride study. However, the magnitude of the doseresponie relation in this cohort is uncertain. We, fat a review supported in part fay Texaco, Inc., and others hive done risk assess ments based on this study and estimate that exposure to 300 ppmyears of benzene would cause 50 to 80 excess leukemia deaths per 1000 workers so exposed.* Tfae risk aueumem of Rinsky et at. ptedieu 250. Birmingham, AL 35294 Hablamd Auurtx, D.Sc. Euxamtm Dclzzli., D.Sc. Pmur Cole, M.D., Da.P.H. University of Alabama at Birmingham School of Public Health *AuM H. Detaell E, Cole P. Bourse sad tcukcmii: a itview of die Outsort md a riak awttintnt Ami Epidemiol (in preu|. 7s Ih EAJar.- In his editorial on new scientific evidence and public health imperatives (April 23 issue),1 Dr. Ashford stated that `an other example is the reanalyds of the National Cancer Institute data on human exposure to formaldehyde,* which now indicate* dear risk of cancer to humane.* The authors of the study of humans exposed to formaldehyde* concluded that "these data pro vide little evidence that mortality horn cancer is associated with formaldehyde exposure at the levels experienced by workers in this study.* Since substantial number* of health worker* are expeaed to formaldehyde, it would be of considerable interest if Dr. Ashford could provide the evidence that indicates "a clear risk of cancer to humans.* St. John's, NF AIB SV6, Canada M. Henky Gault, M.D. Memorial University of Newfoundland I. Ashford NA. New scisnlUic evidence sad public Ssalth impeisdves. NEngl J Med I9B7; 116:10*4-1. Z. Blair A, foreran P. O'Berg M. et a!. Mortality imong Musaisl M*>n exposed to fonusldriiydc. JNCt 1M6:76:107144. 7 for EJlIrr: The editorial by Ashford sounds a false alarm about the slate of public health regulation today. Far from "waiting for the bodies to fol," federal agencies long ago adopted the "preventive public health policies* that Professor Ashford now pleads for. The Supreme Court's decision in the benzene care accepts this approach by authorising OSHA to "risk error on the side of overprotection rather than undetpratcction.*1 The essence of the court's ruling is that this principle must he applied within realistic limits, so that instead of seeking "to eliminate completely and with abso lute certainty any risk of serious harm," regulators must (airly evaluate aH the available scientific data and "make a rational judgment about the relative significance of the risks" involved.1 Federal agencies have recognized that prudence, rather than an illcoaccived ruth tojudgment, it crucial to sound public health regu lation and have had no difficulty implementing the vital risk assessment and policy-making disciplines contemplated |a the ben zene decision.*'4 In fact, OSHA has already regulated asbestos* and ethylene oxide* a* carcinogen* and will shortly prescribe stricter limits for formaldehyde.1 The report by Rinsky et al. on a much-studied cohort of benzene workers, which Profeuor Ashfold cites a* "better scicnoc" requiring an immediate "governmental response," actually illuatratea the pitfalls of reacting uncritically to a aiaglc publication. Indeed, itfoils to meet the standard of scientific excellence to which he subscribes, During OSHA'* public hearings on benxene last rammer,* major shortcomings in the paper by Rinsky et al. were aneovered, includ ing selective use of the available data on industrial hygiene; sub stantial underestimation of exposures, particularly during the 1940*, at the work stations where the excess cases of leukemia oc curred and where workers were known to have died from the acute blood-poisoning effects of benzene*; and failure to account for the prolonged, heavy exposure* to benxene that many of the work ers in this cohort experienced at work stations excluded from the analysi*.*'10 There is nothing to be gained and much to be lost by fomenting a crisis atmosphere based on n Unwed analysis that greatly exagger ates the level of risk, especially since average benzene exposures in the petroleum industry and elsewhere hive for some time been re duced lo levels comfortably below the 1-ppm limit OSHA hat pro posed." Instead, Professor Ashford should recognize, x* the Ameri can Petroleum Institute does, that the best way to improve health protection against the hazards we face today -- occupational and otherwise -- is to insist on a thorough scientific review of all the available data, focusing on the question of what exposures pose significant risks. Washington, DC 20005 WtUiAM F. O'Kura American Petroleum Institute 1. AFL-CtO v. Amtfkaa npolcuM Italian*. MiuUid t/slas Depsitmuu. 441 U.C., 19B0407,696. `' 2. Riwiri M, Orabcr M. Risk oesuatsl in anviranauatai pdicy-MaUag. SefoUM 1*67; 23641640. 3. Law LB. Hakb and safety risk analyte*: Momatioa for better decision*. Sdmec 1987; 236491-3. 4. Otarat D. Tk* safety goals ef the U J Nuckar Regulatory Coomuaio*. fofoaet I9Z7:236496400. J. DapmuMt *| [jm- Oxquiral tspouns to aslratus, asatib. aafoophyUiu. sad aetMha. Fad Rtght. Jaa* 20. 1916; 31:2241290. 6. Departmentcf Labor. Occspetiowlcsceuietoedithut oxifo.Fedltozfat. hue 22,1964; 49.2913*-*^ DO 067930 CONFIDENTIAL YZ0027907 a. Vol. 317 No. 16 CORRESPONDENCE 1039 7. DapwtzrerK of Labor. Semt-snaml ayeoda. Fed Resist. April 17, 1917; 52:14541. I. FOsMtexrini cooirmei of die American Fetroleors Invmar OSHA Docket NO. IVOttC. Ex. 260. lime W. 1916:9.14. 3IS-44*. ri9U 0. Davis PA. Tank substances O the rubber iwXisiry: benzol. Robber Aye L929-J67.*. 71.10. tiftlsre RH. Bcium poison*! in Industry. I Lib Clin Med 1047,27:1517- 11. RurtiOfi HE. SccC LM. Benzene etpast/Tx in the United Stxtzs 1071-1911: in overview. Am J Ind Med I9M; 7:1154], The obove letters were referred to the oulhore of the articles in question. who offer the fallowing replies: T lit Eiiitt: br. Rader in concerned that our onilvib rests on only nine deathi from leukemia and faur from multiple myeloma and may therefore represent merely a description or a random "can ter clutter." That conclusion ii highly unlikely, because of the close aeeoeiaiion of the Caere wllh an experimentally proved carcino gen1'3 and the demonatrated itrong, internally coniiitcnt doseraponie relation. Similar features are characteriatk of lerire of cate* of otfigr chemically induced cancer*, auch a* mesothelioma in aibcilon worker*' and hepatic angiotarcoma in vinyl chloride workera.3 Dr. Bader it correct in noting that no ease* of leukemia devel oped in our aerire amonfc worker* Ant exposed to benzene after 1954. The moat likely explanation far thb finding b a reduction in cumulative exposure; relatively few worken were hired after 1954, and among those worken, total lifetime exposure was kept low by decreases in productibn and progressive diminution in exposure alaadxrdt. Austin ei al. are concerned by what they perceive as "discrepan cies" between the risk estimates derived from our caae-control and standardised mortality ratio analyse*. Given the different nature of these two analyses, auch concern b misplaced. The standardised mortality ratiostudy it intended simply to delineate overall patterns of mortality. It provides a poor basb far ascertainment of an expo sure-response relation, because each dose category within the co hort is a distinct subset with s different duration of fallow-up, a different proportion of deaths, and diffetent age distributions. In addition, the standardised mortality ratio uses an external popula tion for comparison -- namely, the entire population of the United State*. By contrast, the case-control study provides an elegant means lor modeling cumulative dose while controlling lor age, dura tion of (btlow-up, and Other potential confounders and effect modifi ers. furthermore, h employ* an internal comparison group. All that said, however, the apparent discrepancy noted by Austin et *1. u largely an artifact of their manner of representing our data. They arbitrarily chose to derive risk estimates by using the midpoint of each of our exposure categories. A more appropriate procedure, given the stated highly skewed distribution of the cumulative expo sures. would have been to use the person-years weighted average exposure far each category. With that approach, more highly con cordant rbk estimates would have been obtained. Austin et al. are also concerned by a "disparity" between the mean level of exposure to bcniene of all cohort members with out disease (67 ppm-years) and that of the 90 controls (50 ppmyears). This apparent discrepancy is easily explained. The appro priate procedure for tabulatiag doses in a case-control incidence study requires that cumulation of the controls' exposure be trun1 rated at the time of death of each corresponding case.* For all other member* of the cohort, dote eootinuct to accumulate until cessation of exposure. Austin et al. have overlooked this methodofogk point, and thus the two average drees cited by them are trot comparable. Wc are reassured that a separate risk assessment undertaken recently by Austin el al. produced overall findings quite similar to ours.3 Both studies demonstrate an elevated rbk of leukemia with cumulative exposure to benzene, both derive similar dose-response curves, and both indicate that there it a substantial rbk of leukemia at exposure levels below 10 ppm. Mr. O'Keefe atxtre that during public hearings on bensenc held by the U.S. Department of Labor in 1906, "major shortcomings" were uncovered in oue research. O'Keefe fails to note that with our cooperation, he and his staff senninired each datum in our analysis. They found only minor discrepancies among thousands of coded work histories and exposure measurements. We subsequently cor recteri each of these errors, and the Corrections arc included in our published report. Correction of those error* actually increased our estimates of leukemia risk slightly. Furthermore, the environmental measurements were reviewed by the company in whose plants the study was undertaken. The company took no exception to our char acterization of exposures, and they rejected the notion that we had substantially underestimated exposure.' Wc are pleased to note that on September I, 1967, OSHA an nounced a reduction in the standard far permissible occupational exposure to bsnxene from 10 to I ppm. Cincinnati, OH 45226 Ramxt A. Rimsky, Asxxamdsr Bi Smith, Hichams Horurtmo, AndrXa H. Okum, and ProurJ. Lambxmam National Institute far Occupational Safety and Health 1. Snyder CA, Ooldfaeb BD. Sdbkumar AR, Bromberg I. Larkb i. Albert RE. The Wialadoo toxicology ofhrnxtiw: tectdaoce of luinsxipntitir axo plasms and kenMSoaicity In AKR/1 and CJ7BL/6J mice. Tnaka! Affl Phncol I9W, 54:12511. 2. Mnhnnir fibril! Trrtti fl Itratmr s imdipTTVrilisI rsrrbngrn1 nnlli trf kxM-senn Moassnys performed at the Bologna Institute of Omofagy. Am J kid Vied 19J; 4:599430. 1. NTPladuiical ixpoti re do toxicology and carcinogenesis stadias sf teturec In FI44/N Mta and BSC3F1 mica (pvagt Mudies). Reman* Tiirngk Bark. N.C.: National Toxicology Program, 19*6. (Publiemka no. 16-2545 ) 4. tcNkqff U. Hmxsoad EC. Cborg I. Carcinogenicity sf aasotisa atimaos Arch Bnvim Health 1972:25:165-6. 5. Omsk IL Jr, Jtdtmm MN. Angiosarcoma of Ever In 6m maatfaewa of potyvfayl chloride. J Ocesp Mad 1974:14:150-1. 6. Biaaloar NB, labia JH. Mack P. LadghaU B. Multiplicative mode* sad enhol SMlytis. J Am gnt Aaare 1963:71:1-12. 7. Aasda H. Deist!) E. Col* P. Bcnaree aad kskimu: a review of tha funu i and a risk awannunt, Am I Epidemiol (In prats). S. Lake from Goodyear Tbs aad Rubber to NK3SH. October 5, Ml. fa: Oareplonnl tatty and Health Admasbtmtion. Baaataa: Dock* H459. Waahtasoa. DC.: Oocupapotssi Safe? aad Hmhh Atairsukatiou, Techni cal Du Centre. 1916. 7# Mr Ediltr; Despite assertions to the eontrnty by Mr. O'Keefe, federal (regulatory) agenciei have nsf adopted preventive health policies. OSHA waited 15 yean (until 1986) to regulate Mbcstos as a carcinogen -- and then suspended the new standard far non asbestiform fiber*. This could hardly be called a pcavtntivc ap proach, since thousands of asbestos worken died because ef the delay. OSHA also failed to establish a short-term exposure level. Ethylene oxide was only recently regulated because OSHA was sued; OSHA has still refused to define a short-term exprenre level far ethylene oxide that would be required far adequate protection. What Mr. O'Keefe srould probably tall ap ill-conceived rush to judgment is what three concerned with public health would recom mend as a prudent measure. Sufficient evidence tojustify a standard b. like beauty, ia the eye of the beholder. Decision! about whether to regulate can be in error bemuse of uncertainties about the nature and extent of the risk or about tbe economic and technological feasibility of regulatory controls. One type of error b committed when, , because of Insufficient evidence, society fails to regulate an activity that turns out to be harmful. Another type of error ii committed when society regulatet an activ ity that turns out not to be harmful and resources are needlessly expended. Aversion to making these two type* of error* reflects differing value* regarding the nature of the mistakes made and the extent, prevalence, or magnitude of the mistake*. In my opinion, reliance on scientific conventions of causality for public health purposes b limply too ooatly in terms of human life. To dignify a decision not to regulate or a decision to wait lor more evidence, under tbe mantle of Us being scientific, fa to do a disserv ice to both science and public policy. Furthermore, it obscures the value judgment* made. With regard to the regulation of chemicals over the past 17 yean, I cannot think of a stogie regulated substance br which the evi dence baa not grown more convincing with time nr far which a reversal in regulatory policy occurred. Sooner or later, the tip of the DO 067931 CONFTDFNTT Al YZ0027908 1030 THE NEW ENGLAND JOURNAL OF MEDICINE Oct. 15, 1967 iceberg reveals (he iceberg. We ere very for from ill-conceived rushes to judgment. On the contrary, the regulatory agencies have sometimes been dragged kicking and (creaming into action necet*ary Car fulfilling their itatutory mandatci, In the meanwhile, work er* and citifem ire harmed. An example ii the evolution of science regarding the carcinoge nicity of formaldehyde. The National Cancer Institute (NCI) itudy in 1986 asserted that there wat "little evidence that mortality from cancer is associated with formaldehyde exposure at levels experi enced by worker* in this study." In a later publication' the tame author* concluded that Despite small numben, the doae-dependent association of naso pharyngeal cancer with exposure to formaldehyde and particu lates deserves further investigation through case-control studies, where the influence cf formaldehyde and particulates may be evaluated with more statistical power than by standard cohort studies. Further analysis of the NCI data by Sterling and Weinkam* reveals a dearly increased risk of lung cancer. At congressional hearings in 1986, the Director of the NCI, In commenting on the earlier work, testified that "in association with particulates, (here is an aiaodsrioo between formaldehyde and nasopharyngeal cancer, which dearly ha* to be followed up."1'2 3 The irony concerning the critidtm* of the adequacy of the sci ence is that the scientific evidence is essentially there. OSHA ha* just decided to reduce the permissible rxposuie level for benzene to I ppm. It waited far too long. Let there be a better governmental response to the new realities. Cambridge, MA 02139 Nicholas A. Asmrose Maasachuietti Institute of Technology 1. Blair A, Stewart PA. Hoover RN, Fratmteni JF Jr. cl al. Oman at Me |9I-1.nssophaiyaz and orophuyn* and fcmstdchydc cs|nmc. JNCI 19*7; 71: 3. turfing TD. Wehtkam Jl. Sidelined for die record at Du OSHA Heari**i on Formaldehyde SubmUsioe II2B. November 1986. 3. Fmaalttahyds Study. Hsariag brine the Zvbcorankir an Ovsniyis and tavestigatians of tits Commitm on Energy sad Common, Hons cf lUpteseitlhvti, July 21. 1916:106. THE EC-IC BYPASS STUDY 7> At Editor The recent discussion (March 96 issue)1'* of the extracranial-intracranial (EC-IC) arterial bypass study is very timely. I would like to speak to ostc statement in the editorial; "The conclusions of the EC-IC trial are valid for the population of pa tients studied."* The population that underwent surgery included patients who had only ooe episode of the transient ischemic attack- Moat neuro surgeons who are experienced with the bypass procedure would not accept for surgical consideration any patient with a single transient ischemic attack. There is no discussion in the Original report of the randomised study* about bow many of the patients who underwent surgery were in this ordinarily nonoperative group. Subsequent re ports fay the authors of the randomized study have never clarified this luue. Regardless of whether the randomisation of the patients was proper or net, the mere fact that patient! with one transieat ische mic stuck were included in the study negates the concept that the corelusions of the EC-IC trial are valid for the population of the patients studied, Los Angeles, CA 90048 Milton D. Hcinra, M.D. Ccdars-Sinai Medical Center 1. Balmaa AS. 7he cauacnsrial-aiiaeimial antrk) bypass study; Wbai ham ws Nansit N Eagl J Med 19*7: Ji&KK IO. 2. Sandl TM Jr. Wes tin nuematioMl nademiasd rial of cstracsmial lawscnaiil arterial bypass ttfmamMhie ef foe pouvtMioa at risk7 N Eagl J Med 19(7:31t;ll4-6. 3. OoMiiat I. 2nvas N, Langfats T. The Estractmwl Intrsosnkl Bypms Study: reyert it the etmuniuw sgposMtd by die American Association of .Neumtogfcsl Sutgcom to eundne die study. N Enft J Med |(7; 316.117- 20 4. Banisa HJM. Sseken D. Taytor DW. *t al. At* dw letullt of dw wMaiS- IXMaisMsmcemiil hymn trial (cneisliubls? N Eagl J Mad 1917: SIC: 3. The BC/IC Bypau Study Group Failure of cslrscsaaial-ttitncrsital Srtarisl bypass m reduce the risk of isckenic stroke: resolts of an toamstlwal nndomfoed nisJ. N Ea|l J Mad 1913: 313:1191-300. 7r Mr Editor; The Special Reports in the Jkuroaf of March 36 on the validity of the international randomized trial of nttricraniaiintracranial arterial bypau, first published in die Janmi in 1985,* induce some thoughts about the findings. Specifically, the implica tion of the findings for a better understanding of the pathogenesis of ischemic stroke is of interest. The result* are folly consistent with the hypothesis that ischemic strokes are largely embolic in origin. The relations among transient ischemic attacks, completed strokes, and atherosclerotic plaques of the internal carotid artery were well established before the study was done. Emboli from ulcerated plaques or occlusive lesions cf die internal carotid artery or middle cerebral artery would presumably lodge in a brain vessel distal to the anaslooaosis, whose only effect could then be to improve marginal or collateral circulation to the periphery of the territory where the inform occurred. Is it too timpiiitic to assume that in the case of the carotid lesions, a natural bypau already cxiiti -- the drde of Willii? One of the postulates of the study wat that lesions of-the middle cerebral artery would be especially suitable for bypass surgery. In fact, the existence of such lesions generally indicates more severe, widespread atheroadcrotic disease, with the attendant risk ef stroke from embolism originating in the internal carotid artery or oorta or death from coronary heart disease. Montreal, PQ H3A 2B4, Canada Siam Mooac, M.D. McGill University The BC/IC frypwa Study Group. FsButc of catratisadd Innorraaial ansriaf bypass stmduco He risk ef Isehmde wrote: sesuhs of snlnuraatlnoal inutuoi bed trial. N Bag! J Med I9U: 313:1191-200. 7> Mr Editor: The JnMm/ ii to be congratulated for its com plete handling of the controversy surrounding the EC-IC oper ation.1'* However, we strongly disagree with the conclusions of both the neurosurgeons* and the Editor,1 who seems to have been impressed by the neurosurgeons' arguments and to cast a shadow on the proper interpretation of such trial*. We agree that generalizability is strengthened when moat eligible patients are ran domised. but we insist that the results should aland unleu or until an even better study repudiates them. In die meantime, those who insist on using this now-discredited operation should not expect third-party reimbursement until they provide Credible (i-e., wcU-exmtrollcd experimental) evidence that contradicts the BC-tC study. The ralled-for retrospective review of the outcome in the svoorandomised patients would be as worthless as any uncontrolled histori cal survey. It would be impossible to sort out selection factors from treatment effect*. Same patients selected for operation rather than randomisation might do worse than those randomised, because the more threatened patients were treated surgically, and acme might live longer because their good condition made them attractive surgi cal candidates. Whichever predominated, the mult would be nninicrpretable, as demonstrated by several published comparisons of survival of randomised and nonnndomiaed patient* who seemed to have the same prognosis.1** If surgeons have reservations about Use validity of randomized controlled trials because their patients were not entered, the problem is cosily solved by mdudirig all eligible patients in future studies that have the prior approval of those surgeons. In our experience, patients readily accept randomisation when their physicians are convinced of it* validity. When told of the results of the trial and the lack of any evidence (favoring surgery, they would prefer randomization to an operation based on surgical judgment alone. A* suggested by one of us,* the study could be paid for with the money saved by operating on only half as many pa tients. In the meantime, there is no acoeotable evident* shat the --------- DO 067932 CONFIDENTIAL YZ0027909