Document BvRkNKd9GwqErDB6pRQKk5q0w

BENZENE IN FLORIDA GROUNDWATER AN ASSESSMENT OF THE SIGNIFICANCE TO HUMAN HEALTH ) FLORIDA PETROLEUM COUNCIL A DIVISION OF THE AMERICAN PETROLEUM INSTITUTE OCTOBER 1986 t MCD 000006163 Florida Petroleum Council V 325 John Knox Road - Building F / Suite 210 Tallahassee, Florida 32303 American Petroleum Institute 1220 L Street, Northwest Washington, D.C. 20005 *!* EXECUTIVE SUMMARY William D. Preston, Esq., Partner Hopping Boyd Green & Sams. P.A., Tallahassee, Florida Introduction "Si ) "Ni The purpose of the Benzene in Florida Groundwater Study (Study) is to produce, compile, and analyze all available information and thereby comprehensively characterize the probability of potential adverse health effects from human exposure to benzene via groundwater sources. The ultimate goal is to offer the private and public sectors in Florida a meaningful and well informed selection of potential actions to take regarding benzene in groundwater. Benzene is a known human carcinogen which has pro duced an increased incidence of leukemia in highly exposed industrial workers. Carcinogenic effects also have been demonstrated to occur in experimental animals after lifetime exposure to high levels of atmospheric ben zene or to large doses given daily by the oral route. On the other hand, benzene is also a natural substance occurring in low concentrations (parts per million) in many plants and as normal metabolite in certain animal*. It is present in higher concentrations in crude petroleum and is a component of motor fuels. Benzene is produced by the combustion ofmost organic materials and is found in the exhaust of both gasoline and diesel powered vehi cles. As a pure raw material, benzene is used in the manu facture ofdetergents, pesticides, and many other chemical products. At lower concentrations (parts per billion), benzene is ubiquitous in the environment. All humans have a body content, derived primarily from air and food, which exists in equilibrium with the environment. The regulation of benzene in groundwater at such low levels inevitably requires a consideration of its relationship to drinking water and, in turn, the potential impact of that drinking water on the population health risk from benzene from all environmental sources. The salient findings of the Study are as follows: Existing Regulations The Florida "maximum contaminant level"("MCL") for benzene in both public drinking water systems and the most common class of groundwater (Class G-II) is one Mg/1 (one part per billion). This health based standard, which is five times lower than the proposed U. S. Envi ronmental Protection Agency (EPA) MCL, is based, in part, upon risk analysis considerations and is expressly left subject to alteration in light of further Agency under standing of what potential risks exist. Current Florida regulations allow for at least some case-by-case flexibility in the application of this stringent one jug/1 standard in groundwater through the use of "exemptions" and "zones of discharge". Invoking these relief mechanisms essen tially requires a further assessment of potential health risks and other factors on a site specific basis. The State of Florida is expected soon to engage in further rulemaking that will determine what concentra tions of benzene may be left in groundwater pursuant to the "State Underground Petroleum Environmental Re sponse Act of 1986" ("SUPER Act"). Special care should be taken to insure that the regulations reflect the best scientific information available. Hazard Assessment Available literature on benzene toxicity to humans pri marily refers to instances involving high dose levels by inhalation. These observational cohort and epidemiolog ical studies demonstrate that acute and chronic toxicolog ical effects can occur as a result of high exposure to benzene in occupational settings. However, there are no reports of significant toxicological effects as a result of benzene ingestion via drinking water or food. Avenues of human exposure to benzene include food (beef, eggs, etc.) and ambient and indoor air (vehicular sources, cigarette smoke, etc.). Indoor air sources consti tute the most significant contributor ofhuman body con tent of benzene. Drinking water contributes less than 0.2 percent of the average human exposure to benzene. In summary, available scientific evidence and theory indicates that exposure to benzene through drinking water is unlikely to cause any significant adverse health effect in humans. Fate and Transport / Containment of Benzene in Groundwater Gasoline, which typically contains a small amount of benzene, may leak from underground tanks or pipes and thereby release this petroleum product to unsaturated soils above the water table or directly into groundwater. Gasoline is less dense than water, and the primary response to such releases should be to remove as rapidly as possible (by pumping) all of the "free product" that accumulates on top of the water table. This controls further lateral spreading of contamination and greatly reduces the source of gasoline components leaching as a soluble phase into the groundwater. Mathematical and computer models are available to predict and simulate the transportation and fate of ben zene in subsurface systems vulnerable to contamination in Florida. The models developed in this study demon strate that natural mitigation by volatilization and bio degradation are important factors in the total mitigation process. Field observations have confirmed predictions by the model for the time to reach low concentrations (i.c., 10-100 Mg/1 (ppb)] of benzene. The model indicates continuing reductions in benzene due to volatilization and biodegradation. However, Held data indicate that a "leveling off" occurs within the 10-100 pg/l range. Con centrations of benzene below this amount are outside the verifiable range of the model due to the geohydrologicai MCD 0006I64 irregularities, sampling, analytical, and other uncertainties. Analytical uncertainty in the measurement of benzene below 10 Mg/ 1 is high, suggesting that practical demon stration of compliance at low concentrations would be severely complicated by analytical error. Risk Assessment The purpose of estimating exposure-related human health risk is to assist in the establishment of regulations that best balance benefits and risks. In assessing risks associated with the presence of ben zene in underground sources of water, several factors weigh in favor of increased flexibility in the Florida ben zene groundwater standard because: Drinking waterexposure to benzene constitutes such a small percentage of total exposure, the relative risk associated with the presence of benzene at concentra tions higher than the current Florida MCL is slight; Physiological pharmacokinetic considerations show that benzene exposure via water at 20 Mg/ day (perhaps even higher) would not contribute measurably to the normal body content of benzene; and, Quantitative extrapolation of risk is overly conservative. All previous health risk studies have focused upon the concept of "dose". For an analysis to be truly meaningful, 'however, it must account for biological processes (phar macokinetics): i.e., identification of how and at what rates benzene enters the body, is distributed within the body, changes within the body, and is excreted from the body. The primary factor regulating body content of benzene is average concentration of this constituent in the atmos phere. The body content is usually at an equilibrium with concentrations of benzene in the air due to a relatively quick exchange of benzene across the membranes of the lung. Increments of benzene absorbed from the intestine are largely metabolized in the body with the remainder being excreted by exhalation. Benzene absorbed fromthe intestine produces only a transitory increase in body con tent that quickly reverts to a level of equilibrium with the atmosphere. The variability in an individual's total daily intake of benzene makes it difficult to observe any practical differ ences caused by changing the benzene intake from drink ing water by 20 Mg/day (25 m|/1 at 0.8 I/day). Even in the statistical analysis of risk associated with benzene at 25 Mg/1 in drinking water, the upper bound estimate of increased carcinogenic response at that level among indi viduals in the exposedpopulation would be less than 10s or, with equal likelihood, it might be essentially zero. Conclusions Once detected on the groundwater, free phase petro leum hydrocarbons should be removed as quickly as possible to minimize the spread of the contaminant plume. Plume intercept technology is effective in cleaning up gasoline spill sites to low concentrations of benzene. sw Once benzene has reached about 100 Mg/I in the groundwater, continued use of this cleanup action will not yield a substantial improvement over natural pro cesses. Trace residual hydrocarbons left in the subsur face at these concentrations will degrade in time through natural processes. Geohydrological models which predict the relation ship between sources of contamination and aquifers are useful tools as planning guides in projecting the extent of contamination and in evaluating cleanup strategies. The present Florida benzene water quality standard of one Mg/1 benzene is unnecessarily restrictive, both from a perspective of feasible site remedial action and from the standpoint of risk to public health and safety. In the 10-100 Mg/1 concentration range, the risk asso ciated with benzene in groundwater is exceedingly small. A drinking water standard which limits intake of ben zene from this source to 20 pgfd&y (25 Mg/1 at 0.8 i/day) is more than adequate to avoid any detectable risk of leukemia. Such standard should be applied only under circumstances where the groundwater will be used directly for human consumption. Should groundwater with traces of benzene be needed as a drinking water source, it may be more economical to treat the water at the well outlet rather than in the aquifer. HCD 000006165 NOTE TO READER: Authors have been free to select data for their work. The American Petroleum Institute has not imposed a re quirement to use a given data set. This flexibility does not alter the overall conclusions but should be considered in comparing work by different authors. - Although specific models have been used in this study, other models may be equally valid. 2 PART TWO: HAZARD ASSESSMENT Forrest B. Thomas, Ph. D. Shell Development Company Houston. Texas 2-1 TOXICOLOGICAL EFFECTS OF BENZENE 2-1.1 Introduction Several excellent reviews of the toxicological properties of benzene have been published recently: Fishbein (Ref. 2-1.9 [14]), Synder( Ref. 2-1.9 [32]), Aksoy (Ref. 2-1.9(1]) and Mehlman (Ref. 2-1.9 [22]). This section will therefore address only selected aspects of the extremely large toxi cological data base available for this compound in order to provide a perspective from which to evaluate other parts of this document. 2-1.2 Major Sources of Human Benzene Exposure It must be appreciated that benzene is ubiquitous. According to estimates from the National Research Council (Ref. 2-1.9 [24]), the dietary intake of benzene may be as high as 250 Mg daily, perhaps explaining ben zene concentrations of 8-20 ppb in the breath of individu als with no known exposure to this compound. The ben zene content of specific foods is reported to range from 2 ppb for canned beef to 2100 ppb for a boiled egg (Ref. 2-1.9 [23]). Recent results from the National Toxicology Program (Ref. 2-1.9 [25]) indicate that virtually 100% of i benzene administered orally is absorbed into the body. --> Benzene concentrations in ambient air(urban and rural) have been estimated to range from 1-100 ppb (Ref. 2-1.9 [17]). Urban air is reported to contain higher levels than rural air, presumably due to the contribution of automo tive emissions of benzene (Ref. 2-1.9 [5]). After reviewing these data, the National Research Council (1980) calcu lated that an individual living in an urban environment containing a mean atmospheric benzene concentration of 16 ppb (50 Mg/ mJ) who breathes an average of 24 m3of air per day and absorbs approximately 50% of the dose(i.e., equilibrium state) will absorb approximately 600 Mg of benzene daily. [16 ppb = 50 Mg/m3 x 24 m3/day x 50% absorption = 600 Mg/day] Benzene is present in cigarette smoke at levels of 47-64 ppm, leading to estimates of the amount of benzene inhaled from a single cigarettes ranging from 10-31 MgUsing the upper estimate, a person smoking two packs (i.e., 40 cigarettes) per day will absorb up to 992 Mg of benzene (assumes 80% of dose is absorbed; non-equili brium state). (Note: This discussion will not consider the contribution of secondary inhalation of cigarette smoke to the overall benzene exposure of a non-smoker.] [40 cigarettes/day x 31 Mg benzene/cigarette x 80% absorption = 992 Mg/day] The solubility of benzene in water is reported to be 1780 mg/1 at 25 C (Ref. 2-1.9 [2]). In a report issued by the EPA Office of Drinking Water (Ref. 2-1.9 [11]), it was estimated that 97.7% of the population served by public water systems is receiving water either free of benzene contamination or having levels less than 0.5 Mg/1- Esti mates of daily human water consumption range from 0.8 to 2 I /day. Assuming that the average adult consumes 2 liters of water daily, it can be calculated that drinking water with a benzene content of 0.5 Mg/1 would contrib ute 1 Mg of benzene to the average daily dose (100% absorption assumed). [0.5 Mg/1 *2 1 /day = 1.0 Mg/day] Summarizing the above calculations for what are consid ered major sources of human benzene exposure: Non-Smoker Smoker Food Air Cigarettes Water 250 Mg/ day 250 Mg/ day 600 Mg/day 600Mg/day -- 992 Mg/ day 1 Mg/day____________________ 1jug/day TOTAL 1 1. 851 Mg/day 1843 Mg/day 2-1.3 The Pharmacokinetics of Benzene The primary routes of benzene exposure are considered to be oral and inhalation. While there are data that benzene applied as a liquid or in solution to human skin can be absorbed fairly rapidly (Ref. 2-1.9 [4]), this route is gener ally discounted as being significant because of the rapid evaporation of benzene which effectively reduces the time of skin contact. Recent data from the National Toxicology Program (Ref. 2-1.9 [26]) indicates that virtually all of an oral dose of benzene dissolved in vegetable oil is absorbed in rats and mice. It is reasonable to assume that dietary fiber content may reduce both the rate and efficiency of ben zene absorption somewhat by complexing the hydrocar bon, but experimental evidence for this is unavailable. To be conservative, 100% absorption of benzene from food and water was assumed in the above calculations. The respiratory absorption of a hydrocarbon vapor such as benzene is a complex process which has only partially been characterized. Initially, when an animal (or man) is placed into an atmosphere containing benzene vapor, .virtually all of the hydrocarbon is absorbed into the blood stream and then distributed to the various tissues of the body. Each tissue will absorb some of the benzene from the blood with some tissues (e.g., those having a high 7 MCD 000006166 content of fat) absorbing relatively greater proportions of benzene compared to other tissues. The benzene absorbed by each tissue may be sequestered, released back to the blood unchanged, or processed by the specific metabolic enzymes which characterize the cells of that tissue. In time, a state of dynamic equilibrium (often called "steady state") is established between the air, blood, and other body compartments. As more benzene is absorbed from the air, some of the previously absorbed benzene is exhaled unchanged from the body, some is metabolized to specific derivatives which may be further metabolized even in other distant tissues, and some is removed by the kidneys and excreted in the urine. As the animal approaches steady state, the apparent (i.e., net) absorp tion of the compound into the body can be seen to decrease substantially. As noted in Section 2-1.2 above, conservative estimates of 50-80% absorption have been assumed in calculating the contribution of ambient air and cigarette smoking to the total burden of benzene. Recent data from the NTP (1986) indicate that from a 6 hour exposure to 11 ppm of benzene vapor, the apparent absorption of benzene in mice is 50%, whereas at 1000 ppm, the apparent absorption is 9.7%. Values for sim ilarly exposed rats are 33% absorption at 13 ppm and 15% absorption at 870 ppm. Significant differences in the respiratory characteristics of commonly used laboratory animals exist and greatly influence the amount and rate at which a hydrocarbon vapor is absorbed into the body. Small animals, with their . high metabolic rate, must have a relatively large supply of oxygen to the body (Ref. 2-1.9 [34]). While this could have been accomplished evoiutionarily by development of larger lungs relative to their body size, small animals such as mice and rats instead breathe more rapidly. It might be expected therefore that rodents should reach steady state more quickly than a man exposed to the same vapor concentration, but definitive experimental data in this regard have not been identified. The Lovelace Inhalation Toxicology Research Institute (ITRI), under contract with NTP, have characterized the respiratory parameters of the B6C3F1 mouse and the F344 rat, (unpublished information from the butadiene research program). According to ITRI data, the average B6C3F1 mouse weighed 27.5 g and breathed 35 ml of air per minute (i.e., minute volume); the average F344 rat weighed 392 g and had a minute volume of 289.7 ml. Expressed on a kilogram body weight basis, the minute volume of the mouse is 127^ ml/kg and of the rat is 737 ml/kg. From this perspective, it is understandable why Sabourin et al. (1986) concluded that at similar exposure levels of benzene vapor, mice received 150-200% of the dose received by rats per kilogram body weight. Such differences in respiratory characteristics between species are especially important to exposures where the steady state condition has either not been reached or has been perturbed. Consideration of species differences must be incorporated in the quantitative modeling of animal inha lation data for estimation of human health risks. In par ticular, if one assumes a 70-kg man who breathes 7500 ml of air per minute, it can be calculated that the human minute volume/ kg body weight is about one-seventh that of the rat and about one-twelfth that of the mouse. A similar picture of steady-state equilibrium can be developed for benzene absorbed from the gastrointestinal tract. As noted above, recent data from NTP (Sabourin et al., 1986) suggest that essentially ail of a dose of benzene (dissolved in corn oil) administered by gavage is absorbed by rats and mice. Two points should be emphasized with regard to oral exposures. First, the concentration of ben zene in the blood as a result of the administration of an oral bolus is seen to be a transient peak or spike. Dissolv ing benzene in a vehicle such as corn oil essentially results in a retardation in the absorption of benzene into the blood stream, suchthat all ofthe benzene is eventually absorbed, but it requires a longer period of time. Benzene is metabolized via a number of possible path ways, summarized in Figure 2-1.8 [1]. Available informa tion indicates that benzene must be metabolized in order to exert its toxic effects. However, it is not clear at the present time which of the various metabolic pathways activates benzene to more toxic derivatives and which pathways result in detoxification. Various investigators have suggested that toxicity may be the result of covalent binding of benzene metabolites to cellular macromole cules such as DNA and protein, and a reactive benzene epoxide was postulated to be formed during the metabo lism of benzene by the cytochrome P-450 enzyme system (Ref. 2-1.9 [19]). Recent data, however, call into question whether benzene oxide is in fact formed to a significant degree during the metabolism of benzene (Ref. 2-1.9 [20]). Investigators at the Chemical Industry Institute of Toxi cology (Ref. 2-1.9 [16], [18]) suggest that polyphenol derivatives (e.g., hydroquinone and 1,2,4 -benzenetriol) may be responsible for the toxic effects of benzene, per haps via the autooxidative formation of highly reactive radicals which could bind to macromolecular targets. Goldstein et al. (Ref. 2-1.9 [ 15]) suggest that the benzene ring is cleaved metabolically forming muconaldehyde which is also capable of reacting with essential macro molecules. The role of various isomers of diphenol formed by cellular peroxidases, such as myeloperoxidase in the bone marrow in benzene toxicity remains to be evaluated (Ref. 2-1.9 [28]). See Figure 2-1.8 [1]. While it is not yet possible to identify which metabo lite^) of benzene is responsible for the profound cellular toxicity associated with this compound, quantitative risk modeling must recognize that significant qualitative and quantitative differences in the specific metabolic path ways for benzene are seen between species. The phenolic metabolites in the urine of benzene-treated mice, for example, have been found to comprise 50-65%glucuronide conjugates, 26-38% sulfate conjugates, and approximately 5% unconjugated phenol (Ref. 2-1.9 [33]). In contrast, Cornish and Ryan (Ref. 2-1.9 [6]) observed that approx imately 70% of the phenolic metabolites found in the urine of benzene-treated rats were sulfate conjugates. In man, virtually all of the phenolic compounds in the urine following benzene exposure exist as sulfate conjugates __ until the concentration of phenol in the urine reaches . approximately 400 mg/1 when the sulfate pathway has ' apparently been saturated and products of glucuronide conjugation begin to appear (Ref. 2-1.9 [30]). Such data * -O'*06181 8 2-1.9 REFERENCES: TOXICOLOGICAL EFFECTS OF BENZENE Aksov. M. "Benzene as a Leukemogenic and Car cinogenic Agent**. Amer. J. Indus. Med. 8:9-20. I985T Andelman, J. B.. Suess, M. J. "Polynuclear Aro matic Hydrocarbons in the Water Environment", Bull. WHO 43:479-508, 1970. Battifora. H. A.. McCreary. P. A., Hahneman.B. M., Laing, C. H.. Hass. G. M. "Chronic Magne sium Deficiency in the Rat. Studies of Chronic Myelogenous Leukemia" Arch. Pathol. 86:610 ff., 1968. Blank. 1. H.. McAuliffe, D. J. "Penetration of Benzene through Human Skin". Invest. Dermatol. 85:522-526, 1985. Brief, R. S., Lynch, J.. Bernath, T., Scala, R. A., "Benzene in the Workplace", Amer. Ind. Hyg. Assn. J. 41:616-623, 1980. Cornish, H,. Ryan, R. "Metabolism of Benzene in Nonfasted, Fasted, and Aryl-hydroxylase Inhibited Rats." Toxicol. Appl. Pharmacol. 7:767-771,1965. Dameshek, W. "Some Speculations on the Myelo proliferative Syndrome", (editorial) Blood 6:372 ff., 1951. Dameshek, W. "Certain Forms of Leukemia as Immunoproliferative Disorders." In Carcinogene sis: A Broad Critique, Williams and Wilkins Com pany, Baltimore, Maryland, pp 141 ff., 1970. Delore, P., Bergamano, J. "Leucemie Aique en Cours d'Intoxication Bezcnique", J. Med. Lyon 9:227-233, 1928. Environmental Protection Agency, Ambient Water Quality Criteriafor Benzene, (PB8I-117293), 1980. Environmental Protection Agency, Benzene: Occur rence in Drinking Water. Food, and Air, (Prepared by JRB Associates), 1983. Environmental Protection Agency, Carcinogen Assessment Group's Final Report on Population Risk to Ambient Benzene Exposures. (P83-0134), 1978. Environmental Protection Agency, "Notice of Water Quality Criteria Documents", Federal Regis ter 45:79326, November 28, 1980. Fishbein, L. "An Overview of Environmental and Toxicological Aspects of Aromatic Hydrocarbons. I. Benzene." Science Total Environ. 40:189-218, 1984. Goldstein, B. D., Witz, G., Javid, J., Amuroso, M. A., Rossman, T., Wolder, B. "Muconaidehyde, a Potential Toxic Intermediate of Benzene Metabo lism." Adv. Exp. Biol. Med. I36A:331, 1981. Greenlee, W. F., Sun, J. D., Bus, J. S. "A Proposed Mechanism of Benzene Toxicity: Formation of Reactive Intermediates from Polyphenol Metabo lites." Toxicol. Appl. Pharmacol. 59:187-195, 1981. International Agency for Research on Cancer (IARC), /ARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Humans. Lyon, France, 29:93-148. May, 1982. [18] - Irons, R. D. "Quinones as Toxic Metabolites of Benzene". J. Toxicol. Environ. Health 16:673-678, 1985. [19] Jernina. D., Daly, J., Whitkop, B,, Zaltzman- Nirenberg, P., Udenfriend, S. "Role of Arene Oxide-Oxepin System in the Metabolism of Aro matic Substrates. I. In Vitro Conversion of Benzene Oxide to a Premercapturic Acid and a Dihydrodiol" Arch. Biochem. Biophys. 128:176-183, 1968. [20] Johansson, I., Ingelman-Sundberg, M. "Hydroxyl Radical-Mediated, Cytochrome P-450-dependent Metabolic Activation of Benzene in Microsomes and Reconstituted Enzyme Systems from Rabbit Liver." J. Biol. Chem. 258:7311-7316, 1983. [21] Maltoni, C., Conti, B., Cotti, G., Belpoggi, F. "Experimental Studies on Benzene Carcinogenicity at the Bologna Institute of Oncology: Current Results and Ongoing Research." Amer. J. Indus. Med. 7:415-446, 1985. [22] Mehlman, M. A., ed. Benzene: Scientific Debate. Proceedings of the International Conference on Benzene Sponsored by the Collegium Ramazzini, New York City, November 3-4, 1983, Alan R. Liss, New York, 1985. [23] National Research Council. Drinking Water and Health, Vol. 3, National Academy of Sciences, Washington, D.C., 1980. [24] National Research Council. Health Effects ofBei zene: A Review, National Academy of Sciences, Washington, D.C., 1976. [25] National Toxicology Program. Toxicology and Carcinogenesis Studies of Benzene (CAS No. 71- 43-2) in F344(N Rats and B6C3FJ Mice (Gavage Studies), Technical Report No. 289 (galley draft), National Toxicology Program, Washington, D.C., Februap', 1986. [26] Sabourin. P. J., Chen T-H, Lucier, G., Bimbaum, L. S., Fisher.E., Henderson, R. F. "Effect of Dose on the Absorption and Excretion of 14C-Benzene Administered Orally or by Inhalation in Rats and Mice." ToxicoL Appl. Pharmacol. (Submitted for publication), 1986. [27] Santesson, C. G. "Uber Chronische Vergiftung mit Steinkohlentheerbenzin; vier Todefalle." Arch. Hyg. Berl. 31:336-376, 1897. [28] Sawahata, T., Rickert, D.E., Greenlee, W. F. "Metabolism of Benzene and its Metabolites in Bone Marrow." In Toxicology of the Blood and Bone Marrow, Irons R. D., ed.. Raven Press, New York, pp, 141-148, 1985. [29] Selling, L. "Benzol as a Leucotoxin. Studies on the Degeneration and Regeneration of the Blood and Haematopoietic Organs." Johns Hopkins Hosp. Reports 17:83-148, 1916. [30] Sherwood, R. J. "The Interpretation of Monitoring Results", Ann. Occup. Hyg. 15:409-421, 1972. [31] Sinkovics, J. G., Trujillo, J. M., Pienta, R. J.. Ahearn, M. J. "Leukemogenesis Stemming from Autoimmune Disease", In Genetic Concepts and 14 MCD 000006168 2-4 NONDRINK.ING-WATER EXPOSURE David H. Powell. Ph.D. William A. Tucker. Ph.D. Environmental Science and Engineering, Inc. Gainesville. Florida 2-4.1 Occurrence 2-4.1(1) Food Data on the occurrence of benzene in food are limited. Mara and Lee (Ref. 2-4.4 [11]) reported that benzene occurs naturally in fruits, fish, vegetables, nuts, dairy products, beverages, and eggs. These authors report con centrations ranging from 2 micrograms per kilogram (Mg/kg) for canned beef to 2,100 Mg/kg for eggs. Cooked meats are reported to have higher benzene levels than raw meats, and it is postulated that the increased benzene levels observed after cooking meats is due to the break down of aromatic amino acids such and tyrosine (Ref. ,2-4.4 [5]). Low levels (< 10 Mg/ kg) of benzene in food could bedue / to a partitioning from the ambient levels of atmospheric benzene. The high levels observed in eggs indicate an ' ( intrinsic mechanism for the biochemical formation of benzene. Table 2-4.3 [1] summarizes the reported occur rence of benzene in foods. 2-4.1(2) Air The materials balance for benzene indicates that 95 per cent of environmental releases of benzene are to the atmosphere, and three-quarters of this release is asso ciated with fuelcombustion(Ref. 2-4.4[5]). As a result of these emissions, it is not surprising that ambient air levels of benzene have been correlated with traffic volumes (Ref. 2-4.4 [2]). Atmospheric benzene is ubiquitous; remote regions have measured concentrations usually ranging from 1 to 3.5 micrograms per cubic meter (Mg/m3). Higher levels are observed in urban and industrial environments. Table 2-4.3 [2] summarizes benzene concentration ranges and averages for various atmospheric environments. Indoor benzene levels have been studied in industrial settings. Inside chemical plants, reported concentrations range from 2,000 to 10,000 Mg/ m^. The current Occupational Safety and Health Administration (OSHA) regula tion on workplace exposure is 32,000 pgj m3 (10 parts per million, ppm) for the time-weighted average (TWA) con centration for an 8 hour exposure with a peak maximum concentration of 160,000 pgjm3 (50 ppm) for any 15 T~ minute period during an 8 hour day (Ref.2-4.4 [I]). Indoor benzene levels in residences have been reported by Sample and Gilbert (Ref. 2-4.4 [14]) to have a median .value of 15.0 Mg/m3 and an arithmetic mean of 25.8 - - Mg/ m3 foe 353 nighttime observations of benzene. There .-is a minimal correlation between indoor concentrations -and outside ambient levels. The impact of smoking on indoor benzene concentrations appears to be important 60 in households containing one or more smokers. These households exhibit at least 50 percent greater concentra tions than households of nonsmokers. One cigarette can generate approximately 90 micrograms (Mg) of benzene (Ref. 2-4.4 [5]). The portion of the benzene in the main stream smoke is predominantly absorbed by the smoker and not exhaled. Mainstream smoke is that which the smoker inhales; however, the sidestream smoke which is released to the room often contains twice the quantity of some chemicals as the mainstream smoke (Ref.2-4.4 [6]). Therefore, of the 90 Mg of benzene released from each cigarette, possibly 60 Mg is released to the smoker's envi ronment through the sidestream smoke. 2-4.2 Exposure Reported benzene concentrations in foods do not involve all food groups. It is not known how representative these concentrations are of the concentrations in foods in general. Dietary intake of benzene has been estimated to be as high as 250 micrograms per day (Mg/ day) from beef, eggs, and rum alone (Ref. 2-4.4 [13]). Assuming that the average adult male weighs 70 kg, an intake of 250 Mg/day would be equivalent to 3.6 micrograms per kilogram per day (Mg/ kg/ day). In the absence of further data, Letkiewicz et al. (Ref. 2-4.4 [8]) assumed the dietary intake of benzene was at that level. Gilbert et al. (Ref. 2-4.4 [5]) estimated the ingestion due to only those foods with reported benzene concentrations (i.e., butter, cooked beef, eggs, and haddock), resulting in a daily ingestion intake of 31 to 108 Mg/ day. Exposure to benzene in the atmosphere is highly varia ble; reported levels range between low parts-per-billion values in outside air to low parts-per-million in certain industrial settings. Median air concentrations of benzene have been calculated by Brodzinsky and Singh (Ref. 2-4.4 [3]) for rural/remote areas (4.5 Mg/m3), urban/suburban areas (8.9 Mg/m3), and source-dominated areas (9.6 Mg/m3). Thus, in urban/ suburban areas, people inhale approximately 180 Mg of benzene each day (at 20 cubic meters, m3, of air inhaled each day). As a comparison, a one-pack-per-day smoker inhales approximately 600 Mg/ day of benzene from mainstream smoke. Exposure by these routes is substantial, but highly variable in the general population. Average annual atmospheric benzene concentrations and the size of exposed populations have been calculated by Mara and Lee (Ref. 2-2.4 [11]) based on air dispersion models. Approximately half of the population of the United States was estimated to be exposed to average atmospheric benzene concentrations between 3.5 and 13 Mg/ m3. A newborn, formula-fed infant's respiratory intake of benzene can be expected to range from 1.0 to 2.2 Mg/~kg/day, whereas the intake of a nonsmoking, 70kilogram (kg) adult male may vary between 1.5 to 360 Mg/ kg/day, depending on ambient benzene concentra tions (Ref. 2-4.4 [8]). MCD 000006169 TABLE 2-4.3 [1] Foods Reported to Contain Benzene Fruits1 Apple Citrus Fruit Cranberry and Bilberry Currants Guava Pineapple Strawberry Tomato Nuts1 Filbert, roasted Peanut, roasted Macademia Nut Vegetables1 Bean Leek Mushroom Onion, roasted Parsley Potato Soya Bean Trassi, cooked Dairy Products Butter (0.5 Mg/ kg)b Blue Cheese1 Cheddar Cheese1 Other Cheese1 Meat, Fish, and Poultry Cooked beef (2 to 19 Mg/kg)e Chicken (<10 Mg/kg)d Egg. hard boiled (500 to 1,900 Mg/kg)* Egg, uncooked (2100 Mg/kg)h /aoaO Haddock (100 to 200 Mg/ kg)f / ' Lamb, heated (<10 Mg/kg)* Mutton, heated (<10 Mg/kg)d Veal, heated (<10 Mg/kg)* Beverages Cocoa1 Coffee* Jamaican Rum (120 Mg/ kg)` Tea* Whiskey* ' Ref. 2-4.4 [16] " Ref. 2-4-4 [15] * Ref. 2-4.4 [13] d Ref. 2-4.4(12] * Refs. 2-4.4 [9], [10] ' Irradiated and non-irradiated haddock, respectively. Ref. 2-4.4 [7] "Ref. 2-4.4(11] Source: Ref. 2-4.4 [5] ) % t\ I./} J /OOapfo TABLE 2-4.3 [2] Summary of Benzene Occurrence in Air Environment Benzene Concentration (^g/m3) Remote (Range) * Urban (Range) Residential -- Remote from Traffic (Average) Near Chemical Plant (Average) Near Refineries (Average) Gas Stations (Range) Sources: Refs. 2-4.4 [5], [8] l to 3.5 4 to 160 4.5 14 9 <1 to 32 MCD 000006170 61 t 2-4.4 REFERENCES: NONDRINKING-WATER EXPOSURE [1] American Conference of Governmental Industrial Hygienists (ACGIH), Threshold Limit Values for Chemical Substances and Physical Agents in the Work Room Environment. Cincinnati. Ohio, 1985. [2] Battelle, Environmental Monitoring -- Benzene, Battelle Columbus Laboratories, Columbus, Ohio, 1979. [3] Brodzinsky, R., Singh, H. B. Volatile Organic Chemicals in the Atmosphere: An Assessment of Available Data, prepared by SRI International, Menlo Park, California for Environmental Scien ces Research Laboratory, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, No. Carolina, EPA-440/4-79-029b, 1982. [4] Drill, S., Thomas R. Environmental Sources of Benzene Exposure: Source Contribution Factors, Prepared by Mitre Corporation for the U. S. Envi ronmental Protection Agency, EPA-570/9-79-004, 1979. [5] Gilbert, D., Byrne, M., Harris, J., Steber, W., Woodruff, C. An Exposure and Risk Assessment for Benzene, Final Draft Report, Prepared by Arthur D. Little, Inc. for U. S. Environmental Pro tection Agency Office of Water and Waste Man agement, Washington, D. C. EPA Contract No. 68-01-5949, 1982. [6] 'Johnson, W. R., Hale, R. W., Nedlock, J. W., Grubbs, H. J., and Powell, D. H. "The Distribution of Products between Mainstream and Sidestream Smoke", Tobacco Science 17:141-144, 1973. [7] Leibich, H. M., Koenig, W. A., Bayer, E. "Analysis of the Flavor of Rum by Gas-Liquid Chromato graphy and MassSpectrometry" /. Chromato. Sci. 8:527-533, 1970. [8] Letkiewicz, F., Johnston, P., Macaiuso, C., Elder, R.t Yu,W., Bason, C. Occurrence of Benzene in Drinking Water. Food, and Air, Prepared by JRB Associates for U. S. Environmental Protection Agency Office of Drinking Water, Contract No. 68-01-6388, 1983. [9] MacLeod, A. J., Personal Communication to H. I. Chinn, (Cited in Drill, S., Thomas, R., Environ mental Sources ofBenzene Exposure: Source Con tribution Factors. 1979), 1977. [10] MacLeod, A. J., Cave, S. J. "Variations in the Volatile Flavour Components of Eggs", J. Sci. FoodAgric. 27:799-806, 1976. [11] Mara, S. J., Lee, S. S. Assessment ofHuman Expo sure to Atmospheric Benzene, U. S. Environmental Protection Agency, Research Triangle Park, No. Carolina, EPA^50/3-78-031, 1978. [12] Merritt, C. "Qualitative and Quantitative Aspects of Trace Volatile Components in Irradiated Foods and Food Substances", Radiation Res. Rev. 3:353368, 1972. [+3] National Cancer Institute (NCI). On Occurrence, *_ Metabolism, and Toxicity Including Reported Car cinogenicity of Benzene. Summary Report, Wash ington, D. C., 1977. [14] Sample, C. J., Gilbert, D. Indoor Ambient Benzene Concentrations: An Assessment ofFactors Related to Indoor Air Quality. American Petroleum Insti tute, Washington, D. C., 1985. [15] Siek, T. J., Lindsey, R. C. "Semiquantitative Anal ysis of Fresh Sweet Cream Butter Volatiles", Jour nal of Dairy Sciences 53(6):700-703, 1970. [16] Van Stratten, S., Editor. Volatile Compounds in Food. 4th Edition, Supplement 1, Central Institute for Nutrition and Food Research TNO, Zeist, The Netherlands, 1977. tics Oq 62 *J) iy OJ.rs} ^ V/ul*7 t?77 fct o$j> e^Z^t '^r-~^ },b*~fk -* 0,/ '*tr?% ( r&t^ - - V Nov, 1L r. -7** v C'Ccrfit / lL ^X *r-, \ ! .. Jo&Z, X^T/ O ^ f~{ s( ^ /?77 A-- (JLjttSr <X yi^n. ^tVvJ> ajt j ' OlluZr '" JcsZ -Z-J ^^/4"vv'- it-^t^r A-'p/ /4T, *- ,w~ j^ V (S> kZl: swi~ Zr C^-tC^Lt 5- " ............... - /ya^-^-c^-^7~"<-r* y *? j--^ *'-*=-'S\ p~**~fr--V'-` OL via- ^- LjU? 7y <b-5 ^, ...' -%*/-*? i?77 fct J^5 0,f yrtrP% , '^., y.^^.P . P -&t /A -S2t 5 j?- / -W / %,~'.y *UL 'OUs nJLyJterri v/^J-- /tZ->J*& ri ' o' ^ '//7'7 ^/r>? V,- <>---<- t,^ ^;/ f/' . , C --CC7fc /" "7 MOD 000006173 k&ttf**** -..<.< .t,,; 7t/<v ./ *& &. MU-*k~m+ .j.'cT^ ^ ^-'-4 *&*/ ^ Jj4f*y (Lf. c' f .jLT-c^`CcA r / ';*.*' j'i * * t . ^-- - ' ' '"' i -/--ZT~3C l V ^?/o 0-r r v G f$ /'> f"/ - l r--t> f~f .t--*{ ^ G. , :'-- $ -f~ Q cri-- )0l6 nr JU*TUu <tr' r i c^t (j ^/^p A7X^ k} /) & f $!<)li[j~ - prt-iw* a-* r / 4 + $# *1. ? ? K" il Gt-yy^r*/ o b 'Ta'iccf f'f ^ ytq ;/* *,-$ 4 \y<i C MCD 000006174 j& 'h** V ^ > a^ /Lc-y- i O' j^^.kZfLT A. : 4. t / ~iCt-> J / c 16 (Ftf A4 H CFR ISn.if Tr /> (' V'^4,+ -r.e-f' rj jf ^rf <*fR ff/ojoze ~CT~R--fTtcrr&fr ?Tly_ ^/?~ry ' / O S /?<$ VLr- y^/^r (' Srd-t id gjjtt. MCD 000006175 f 1500.14 ucntoui (i-i-*i ummI) UM.14 PMwcta retrial tpccimi lWK fc* nte rtiw Kb) ofOtket. (a) Human experience, me reported in the scientific Uterature end to the Poison Control Center* end the He* ttOnel Gearing House for Poison Con* Ml Centers, end opinions of informed medical experts establish that the fol lowing substance* ere hscardous: (1) Diethylene glycol end mixtures 10 percent or more by weight of diethylene glycol. (3) Ethylene glyool end mixtures containing 10 percent or more by weight of ethylene glyool. (1) Products 6 percent or more by weight of benzene (also known es benzol) end products con* 10 percent or more by weight of toluene (also known as toluol), xylene (also known es xylol), or petro* Wum distillates such as keroainc, min eral seal oQ. naphtha, gasoline, miner al spirits. Stoddard solvent, and related ptfrnUnm distillates (4) Methyl alcohol (methanol) and mixtures containing 4 percent or more by weight of methyl alcohol (metha nol). (9) Turpentine (including gum tur pentine. gum spirits of turpentine. --wood turpentine, sul fate wood turpentine, and destructive ly distilled wood turpentine) and mix tures containing 10 percent or more by weight of such turpentine. <b) The Commission finds that the following substances present speeds) hazards and that, for these substances, the labeling required by section kpKl) of the act Is not adequate for the protection of the public health, tinder section 3(b) of the act, the fol lowing specific label statements are deemed necessary to supplement the ^Vllnr required by section 2<pXl> of the act! (1) Diethylene glycol Because dieth- jlx>e glycol and mixtures containing 10 percent or more by weight of dleth- jlcat glycol are commonly marketed, stored, and used in a manner increas ing the possibility of accidental Inges tion. such products shall be labeled with the signal word "warning" and the statement "Harmful If swallowed." (3) thyi*n* glweol Because ethylene glycol mixtures containing 10 per cent or more by weight of ethylene glycol are commonly marketed, stored, and used in a manner increasing the possibility of such products shall be labeled with the signal word "warning" and the statement "Harmful or lowed." if swal* * (3) Bentne. toluene, xylene; petrol*. ** sm distillates. (1) Because Inhalation of the vapors of products eantateteg 5 percent or more by weight of benzene may canoe Mood dyscrasias. such products be libeled with the signal word "danger." the statement of hazard "Vapor harmful.** the word "poison." and the skull and crossbone* symbol. If the product contains 10 percent or more by weight of benzene, it shall bear the additions! statement of hazard "Harmful or fatal if swal lowed** end the additional statement "Call physician Immediately." <il> Became products containing 10 percent or more by weight of toluene, xylene, or esy of the other substances listed In paragraph <aX3) of this sec tion may be aspirated into the lungs, with resulting chemical pneumonitis, pneumonia, and pulmonary sitna, such products shall be labeled with the signal word "danger." the state ment or hazard ''Harmful or fata) If swallowed," and the statement "Call phyddan Immediately." (Ill) Became Inhalation of the vapor of products containing 10 percent or more by weight of toluene or xylene may cause systemic injury, such prod ucts shall bear the statement of hazard "Vapor harmful" in addition to the statements prescribed in para graph <bX3Xll> of this section. (4) Methyl alcohol (methanol). Be cause death and blindness can result from the ingestion of methyl alcohol, the label for this substance and for mixtures fr^g 4 percent or more by weight of this substance shall in clude the signs) word "danger." the word "poison." and the skull and uuwbtmn symbol. The of hazard include "Vapor harmful" and "May be fatal or cause blindness if swallowed.*' The label shall also bear the statement "Cannot be made nonpoisonous." (6) Turpentine. Because turpentine (Including gum turpentine, gum spirits mCD 000006176 ** 3-26-92 A check of the ,'CFR/Fed -keg. updating information has found no amendments nor proposed amendments to the above 16 CFR Sec. 1500.14(b)(3) since that language was published 1-1-91. --EKB LABORATORY NO.: 10/6/83 Page 4 J-23-33 TABLE II (Continued) TYPICAL BASE GASOLINE STREAMS LAKE CHARLES REFINERY - SUMMER 1983 Ponca City Sample No.: Lake Charles Sample No.: S tock Gravity, "API Distillation, D-86, F, 760 mm IBP 5% Evaporated 10% Evaporated 20% Evaporated 30% Evaporated 50% Evaporated 70% Evaporated 90% Evaporated 95% Evaporated End Point Recovery, Vol.% Reid Vapor Pressure, psi Sulfur, Wt.% Aromatics, Vol.% Olefins, Vol.% Existent ASTM Gum, mg./lOO mis. Benzene, Vol.% Research Octanes Clear 0.25 gms./gal. TEL 0.5 gms./gal. TEL 1.5 gms./gal. TEL Motor Octanes Clear 0.25 gms./gal. TEL 0.5 gms./gal. TEL 1.5 gms./gal. TEL Approved: 1611 727 No. 2 Reformer Charge 57.5 129 181 208 225 234 259 283 312 321 339 97 8.2 <0.01 11 1 <1 1.0 53.8 56.4 59.4 68.7 53.4 56.3 60.8 71.4 1609 725 No. 2 Reformate 49.1 115 148 163 184 201 240 278 321 338 388 98 5-5 <0.01 49 1 2 3.8 94.7 96.3 97.7 100.0 35.2 86.6 88.0 90.5 1781 853 No. 3 Reformate 44.4 101 125 146 178 203 246 281 325 344 404 98 7.9 <0.01 63 1 1 6.0 100.9 102.0 102.8 104.3 89.0 89.6 90.2 92.2 Senior Technologist bp C' Associate (technologist Men 000006177 CONTINENTAL OIL COMPANY PONCA CITY, OKLAHOMA REFINING TECHNICAL SERVICES LABORATORY Pit.: PC File: 662.1 *924 Date: 6-8-77 LABORATORY NO.: CHARGE: SUBJECT: F-25-77 PC 49 Summary of Benzene Content of Gasoline and Blending Streams - Ponca City Refinery ANALYTICAL DATA: Vol..% Benzene of Finished Gasolines Sample Number Sampl e Sample Date Benzene, Vol. TK 114 Unleaded TK 151 TK 101 Regular Premium TK 150 Regular TK 148 Premium TK 156 Regular TK 156 Regular TK 150 Reaular TK 161 Unleaded TK 148 Premium TK 155 Regular TK 102 Premium TK 167 Regular TK 114 Unleaded TK 156 Regular TK 170 Regular TlC 155 : ! Regular TK 167 Conotane TK 116 Unleaded TK 102 Premium TK"T5"3 Um. Bros. TK 151 Um. Bros. TK 156 Regular TK 150 Regular TK 155 Regular TK 167 Regular TK 150 TK 148 R-92 Premium TK 149 R-92 TK 155 TK 156 . R-93 TK 102 TK 170 TK 150 TK 155 Regular TK 153 Premium J cc: IFW-JLD-(ML-BDB)-KCH-F Premium Regular March 1977 March 1977 March 1977 5-9-77 5-9-?* 5-9-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-10-77 5-12-77 5-12-77 5-12-77 5-13-77 5-14-77 5-15-77 5-17-77 5-18-77 5-18-77 5-20-77 5-21-77 5-22-77 5-24-77 5-24-77 5-25-77 5-25-77 5-29-77 5-29-77 0.6 1.0 0.6 0.8 0.2 0.8 1.1 0.9 0.6 0.2 0.8 0.6 1.1 0.6 0.8 1.1 0.8 1.1 0.6 0.6 0.3 0.9 0.8 0.8 0.7 1.1 0.9 0.2 1.1 0.7 1.0 0.3 1.1 0.9 0.8 0.4 MCD 000006179.1 LABORATORY NO.: June 8, 1977 Page 2 P-25-77 Sample Number TK 150 TK 641 McConnell Sample Regular Q Grade PC JP-4 Vol.% Benzene of Finished Gasolines Sample Date Benzene, Vol.% 5-29-77 5-23-77 6-2-77 0.9 <0.1 0.1 Sample Number PC 5952 PC 5962 PC 5963 PC 5965 PC 5966 PC 5954 PC 5958 PC 5957 . i l f />rTti,w Vol.% Benzene of Refinery Streams Sample Sample Date Benzene, Vol.% Straight Run Gasoline No. 3 Reformer Charge No. 3 Reformate No. 4 FCC Lt. Gasoline No. 4 FCC Heavy Gasoline Coker Gasoline No. 5 FCC Heavy Gasoline No. 5 FCC Liqht Gasoline No. 5 FCC Gasoline Cat Poly Gasoline Straight Run Gasoline No. 2 Reformate No. 1 CTU Raw Crude No. 2 CTU Raw Crude No. 4 CTU Raw Crude No. 5 CTU Raw Crude - . 4-4-77 4-4-77 4-4-77 4-4-77 4-4-77 4-4-77 4-4-77 4-4-77 5-13-77 5-17-77 5-12-77 5-26-77 6-7-77 6-7-77 6-7-77 6-7-77 1.4 0.2 1.3 0.3 <0.1 0.1 0.6 0.5 0.5 <0.1 1.0 1.2 6.1 <0.1 0.1 0.1 Approved: Senior Technologist bp y;rA-,T--y Associate Chemist MCD 000006179.2 Oran D. S. .ey To Ken Hunt (c loco) Date 7-19-77 For your information O.D.S. CKH RSJ '3 ^ai***^ & i . */. h* <=, U o-J ? WCD 000006182 ' 204 Require employees to remove and leave protective clothing at the point 0/ use. and to require employees to con fine the use of the clothing to specific operations. Prohibit the storage and consumption of food, beverages, or tobacco in regulated areas. Provide for pressure-negative air flow while the MOCA is being transferred from drums to melting facility. Provide for reasonable cleaning procedures for surfaces, of equipment taken or removed from regulated areas. Post at each entrance to regulated areas a sign reading "Restricted Area, Authorized Personnel Only, MOCA." Provide to each employee, prior to his being authorized to enter regulated areas, a training and indoctrination program appropriate to comply with the settlement agree ment. Provide and require the use of approved and properly maintained dust respirators for employees while they are engaged in transferring MOCA from drums to melting facili ty whenever direct contact with MOCA dust may occur. No OOl Response Sather told OSHR that he had not discussed with the Labor Department solicitor's office his assertion that the terms of the agreement form a legal precedent. However, he main tained, "it would be hard for them to say something else should be done" to control MOCA exposure in a similar situation after having reached agreement with Roadway. A spokesman for the solicitor's office declined immediate comment on Sather's assertion. Hearings on a new MOCA standard were held in 1975, but no standard was ever issued. Former Assistant Labor Secretary Morton Corn in November 1976 declined a National Institute for Occupational Safety and Health re quest to issue an emergency MOCA standard, maintaining that such an action would involve "thorny legal problems" for DOL (Current Report, December 9, p. 858). GAO WARNS OF POTENTIAL HAZARD IN USE OF RESIDUAL OIL FUEL-URGES OSHA ACTION The Occupational Safety and Health Administration should give "prompt attention" to a potential benzene hazard among workers in power generation and steam-heating plants, the General Accounting Office urged on July 5. In a letter to Labor Secretary Ray Marshall, Gregory J. Ahart. director of the GAO human resources division, reported that a GAO investigation had found two leukemia-related deaths among workers at the Naval Regional Medical Center in Portsmouth, Va. Both workers had been employed at the facility's powerhouse, where a residual fuel oil called "number six fuel" is used. Ahart noted that according to information supplied by the Defense Department's Defense Logistics Agency, the amount of benzene in a batch of number six fuel "could amount" to one-half of one pcrcenl by weight. Although we are nol ronrlmling that there was a direct relationship between exposure to benzene or I he other toxic substances which may be luunti in number six fuel and the two leukemia-related deaths, we believe the evidence on the adverse effects of benzene alone is enough to warrant prompt attention to this matter," Ahart declared. Both deceased Medical Center employees, Ahart reported, worked in the powerhouse for over 20 years. One worker died of an acute intracerebral hemorrhage due to myelogenous leukemia, and other from a cerebral OCCUPATIONAL SAFETY & HEALTH REPORTER hemorrhage resulting from the subacute myelogenous leukemia. Medical records indicated that traces of benzene were found in the latter employee's blood, according to the GAO official. A 1973 survey by Medical Center industrial hygienists, conducted after the death of the second employee, concluded that "the second employee's problem was not due to ex posure to chemical vapors in the work environment," Ahart related. However, he noted, there apparently was no testing for benzene, or taking of air samples. In January 1977, at GAO's request, an OSHA industrial hygienist surveyed the powerhouse, took air samples, and analyzed a sample of number six fuel for benzene. GAO found that: Air samples taken in the general working areas of the powerhouse showed that benzene vapor concentrations were less than one part per million, although samples taken at fuel filters indicated concentrations exceeding 60 ppm. Fuel oil samples indicated a benzene concentration of about one-tenth of one percent by weight. Employees who cleaned the fuel filters wore either no gloves or cloth gloves only, so that they "frequently" got the fuel on their hands, arms, and clothing. Powerhouse employees were not participating in any medical surveillance program, according to the powerhouse foreman. Corrective Maaturti In a subsequent discussion with Medical Center officials, Ahart stated, the OSHA industrial hygienist recommended that the Medical Center require the use of synthetic material gloves, reengineer the fuel filtration system, and prohibit open buckets of fuel oil in the powerhouse. Later, in a February 1977 visit, GAO "observed that signs had been posted in the powerhouse cautioning employees to avoid skin contact with the petroleum products in use and in forming them of mandatory requirements for p. elective gloves and respirators," according to Ahart. Because of "the seriousness of occupational exposure to benzene and other toxic substances which may be found in number six fuel," OSHA should inform federal agencies and private industry of the health hazards which may be created by the handling and use of this and other residual fuel oils. Ahart recommended. Further, residual fuels should be included as a potential health hazard "which should be checked for during OSHA's inspections and surveys of workplaces," he added. Number six fuel, he noted, is used "extensively" by power generation and steam-heating plants, and its use "could cause dangerous exposure of employees if appropriate safeguards are not taken." Ahart noted that OSHA in April issued an emergency benzene standard that was to have become effective May 21. However, the standard was stayed temporarily by the Fifth Circuit Court of Appeals, a stay, still in effect (Current Report. May 26. p. 1587). A permanent benzene standard was proposed on May 27, hearings on which are to begin July 19 in Washington, IJ.C. (Current Report, June 2, p. 3). MCD 000006183 Beryllium NIOSH STUDY FINOS EXCESS OF CANCER AMONG WORKERS AT EXTRACTION FACILITY A "significant excess" of cases involving brochogenic cancer and other respiratory and heart diseases occurred among employees exposed to beryllium at a Reading, Pa.. XT r Oecuparionol Safety & Health Reporter  EPA proposes a benzene NESHAP ior cotce oven by-product recovery plants (49 FR 23522--23555* 6 June 1984). EPA withdraws the proposed NESHAP for maleic anhydride plants, ethyl benzene/scyrene> plants, and benzene storage vessels (49 FR 23558-23566, 6 June 1984). [Note: a notice of EPA1 s proposal to withdraw was published in the 6 March 1984 Federal Register] ____ ______ ___________ EPA finalizes the benzene NESHAP for. fugitive emissions from petroleum refineries and chemical plants (49 FR 23498-23520, 6 June 1984). _________ THE FINAL FUGITIVE--BENZENE NESHAP NESHAP apply to both new and existing affected facilities* Compliance is required within 90 days (i.e., starting from June 6) unless a waiver is obtained. Affected facilities in this case are the sum of equipment in benzene service located within a discrete process unit. "Equipment" includes valves, pumps, compressors, pressure relief devices, sampling connections, open-ended valves or lines, flanges and other connectors, and product accumulator vessels. "In benzene service" means containing or contacting a stream that is at least 10 percent benzene by weight* Plant sites that produce less than 1,100 tons of benzene per year are exempt. The benzene NESHAP itself is a new Subpart J to 40 CFR Part 61* It appears on p. 23513 of the 6 June 1984 FR notice. Subpart J refers to another new Subpart (i.e., V) for the specific control requirements* Subpart V of Part 61 is an all-purpose NESHAP for volatile hazardous air pollutants (VHAP), of which benzene is the first to be included. Subparc V is also given on page 23513. Requirements under Subpart V of Part 61 are substantially the same as the NSPS (i.e., Part 60) requirements for VOCs from refineries and chemical plants. [Note: on 30 May 1985 (49 FR 22598-22608), EPA finalized the NSPS for fugitive VOCs from refineries, making the control requirements the same as for fugitive VOCs from chemical plants. The chemical plant fugitive V0C NSPS is Subpart W of 40 CFR Part 60 and is published at 48 FR 48335, 18 October 1983* The refinery fugitive V0C NSPS is now Subpart GGG of 40 CFR Part 60, and refers to Subpart W (i.e., the chemical plant NSPS) for specific control requirements*] Again, the practices and control methods required by the fugitive benzene NESHAP are substantially identical to those required by the fugitive VOC NSPS. Basically, the requirements are as follows: (1) periodic leak detection/repair for valves and pumps, and (2) installation of equipment for containing leaks from compressors, sampling connecting systems, open-ended valves/lines, and accumulator vessels. Initial review shows that no equipment at our domestic refineries is "in benzene service." This is based on the assumption that the 10-percentbenzene criterion is not met during the production of gasoline. That assumption needs to be^ verified (Recotmended Action -- K* C. Hunt). Future projects at our refineries could trigger the NESHAP (i.e., for the affected process units only). An example would be the proposed para-xylene project. However, such projects would trigger the NSPS for refinery fugitive VOCs anyway, so that_the same requirements would have to be met whether the NESHAP is triggered or not. Thus, no serious MCD 000006184 vV'.! SSi 1r 7. 5 7 - 6.U4. / f?7'->=' Y<.rh / / i -*h< ^ /./-/ 3 W*\/) #1 'hi 0. ~ 31 7j .03, //0^- h-r'l i'h h*~ J-h hi' 2 7- OJ o. v- o. v- o *V A i-r ' 3,3 ,;i'* ' $(>P) 3>>e f, */cJ* o/{ /,> jy "7j ' <r a / 0. r' <?, ^ 0.f <f 0. / < o,, 2, * - V7 3-f - /;tT / O' /,->, <2.0, / -- O.^ MCD 000006185 il . ; 'CC'J :. , oj 1 _j" - C'-ja- VOL.% BENZENE IN FINISHED GASOLINE PC 1538 PC 1539 PC 5998 PC 5999 PC 5000 BILLINGS REFINERY Bi 300 Regular March 1977 Bi 301 Premium March 1977 SAS Regular 5-11-77 SAS Premium 5-11-77 SAS Unieaded 5-11-77 PC 2419 PC 2426 PC 2298 DENVER REFINERY De 77-124 Unleaded March 1977 Denver Regular March 1977 De 77-128 Premium March 1977 Regular PC 1781 PC 1782 PC 5001 PC 5002 PC 5003 WRENSHALL REFINERY Regular March 1977 Premiurn March 1977 SAS Regular SAS Premium SAS Unleaded PC 1520 PC 1521 PC 1522 PC 1839 PC 1840 PC 1841 LAKE CHARLES REFINERY LC 232-77 Unleaded March 1977 LC 344-77 Regular March 1977 LC 345-77 LC 640-77 LC 641-77 LC 642-77 Premium Regular Premium Unleaded May 1977 May 1977 May 1977 May 1977' PC 1434 PC 1435 ' PARAMOUNT REFINERY PTX-2-77 Unleaded March 1977 PTX-2A-77 Premium March 1977 VOL.f; 0.9 0.5 1.1 0.5 0.7 VQL.% 0.5 0.5 0.6 0.6 VOL.% 0.5 0.7 0.7 0.8 0.8 VOL.% 1.5 1.0 1.1 1.1 1.0 1.1 1.2 1.0 WCD 00006IS6 (a) Scope and Application The Standard becomes effective on December 10, 1987, and applies to all occupational exposures to benzene. Attachment 1 outlines the completion dates for the requirements within the standard's sections. o Exempt: - Storage, transportation, sale, or use of fuels after final discharge from bulk wholesale facilities. - Loading and unloading operations at bulk wholesale facilities with vapor control systems for all loading and unloading operations. - Storage, transportation, distribution or sale of materials containing >0.1% benzene in intact containers or transport pipelines while sealed. - Containers and pipelines with <0.1% benzene. - Natural gas processing plants processing gas with <0.1% benzene. NOTE: Since the potential exists for benzene to concentrate within different streams in natural gas plants, it is recommended that streams be sampled to determine those which may contain >0.1% benzene and that locations be placed under the standard accordingly. - Oil and gas drilling, production and servicing operations. - Cleaning and repair of barges and tankers are excluded from: (e)(1) Exposure Monitoring - General (e)(6) Accuracy of Monitoring (f) Methods of Compliance - Work operations with liquid mixtures containing: MCD 000006187 <0.5% benzene - until September 12, 1988 <0.3% benzene - until September 12, 1989 <0.1% benzene - after September 12, 1989 NOTE: It is recommended that work operations with liquid mixtures containing >0.1% benzene be considered as covered by the standard immediately. This will make compliance assurance less complicated relative to monitoring requirements. Attachment 2 is a list of CONOCO products and intermediate refinery streams which contain >0.1% benzene as reflected on the Conoco Material Safety Data Sheet (MSDS). All operations must comply with the OSHA Hazard Communication Standard (29 CFR 1910.1200) and the emergency provisions of the benzene standard. Exemptions are still covered by the previous exposure limits (8-hour TWA = 10 ppm; ceiling = 25 ppm; max peak above ceiling for an 8-hour shift = 50 ppm for 10 minutes max duration). (b) Definitions "Authorized person" means any person specifically authorized by the employer whose duties require the person to enter a regulated area* or any person entering such an area as a designated representative of employees for the purpose of exercising the right to observe monitoring and measuring procedures under paragraph (1) of this section, or any other person authorized by the Act or regulations issued under the Act. "Benzene" (C6H6) (CAS Registry No. 71-43-2) means liquefied or gaseous benzene. It includes benzene contained in liquid mixtures and the benzene vapors released by these liquids. It does not include trace amounts of unreacted benzene contained in solid materials. "Bulk wholesale storage facility" means a bulk terminal or bulk plant where fuel is stored prior to its delivery to wholesale customers. "Container" means any barrel, bottle, can, cylinder, drum, reaction vessel, storage tank, or the like, but does not include piping systems. "Day" means any part of a calendar day. 000006188 MCD "Emergency" means any occurrence such as, but not limited to, equipment failure, rupture of containers, or failure of control equipment which may or does result in an unexpected significant release of benzene. "Employee exposure" means exposure to airborne benzene which would occur if the employee were not using respiratory protective equip ment. "Regulated area" means any area where airborne concentrations of benzene exceed or can reasonably be expected to exceed, the permissible exposure limits, either the 8-hour time weighted average exposure of 1 ppm or the short-term exposure limit of 5 ppm for 15 minutes. "Vapor control system" means any equipment used for containing the total vapors displaced during the loading of gasoline, motor fuel or other fuel tank trucks and the displacing of these vapors through a vapor processing system or balancing the vapor with the storage tank. This equipment also includes systems containing the vapors displaced from the storage tank during the unloading of the tank truck which balance the vapors back to 'the tank truck. 2 (c) Permissible Exposure limits (PEL's) (c)(1) Time-Weighted Average Limit (TWA) o 1 ppm as an 8-hour TWA. (c)(2) Short-Term Exposure Limit (STEL) o 5 ppm as averaged over 15 minutes. NOTE: There is also an Action Level of 0.5 ppm (8-hour TWA) that effects monitoring, medical surveillance and training requirements. (d) Regulated Areas o All locations/operations which exceed or can reasonably be expected to exceed either of the PEL's (TWA or STEL) must be designated as a regulated area. This includes maintenance and other temporary types of operations. o All regulated areas must be demarcated in a manner that limits employee access into the areas; e.g. ropes, markings, barricades, gates, etc. (See (j) Communication of Benzene Hazards to Employees for sign requirements.) o Access to regulated areas must be limited to authorized persons. (e) Exposure Monitoring (e)(1) General MCD 000006189 o Personal (breathing zone) air samples must be used to determine representative employee exposures. o Representative 8-hour TWA employee exposures must be based on monitoring representing the full shift exposure for each potentially exposed job classification, on each shift, in each work area covered by the standard. (See Scope & Application for exemptions.) o STEL measurements are to be based on 15-minute personal air samples measured during tasks where exposure potential is high; e.g. gauging, sampling, opening tanks, lines and process equipment, etc. Grab samples (detector tubes, real time monitors) may be used to determine where 15-minute STEL monitoring is required. o After the initial monitoring phase, only the shift showing consistently higher exposures for a job classification requires periodic monitoring. NOTE: It is recommended that passive organic vapor monitors (POVM's) 3 PC 1842 PC 1843 PC 1844 PC 1819 PC 1346 PC 1847 PC 1848 PC 1849 PC 1850 VQL.% BENZENE OF REFINERY STREAMS LC 643-77 LC 644-77 LC 645-77 LC 646-77 LC 644-77 LC 648-77 LC 649-77 LC 650-77 LC 651-77 LAKE CHARLES REFINERY (May 1977) Coker Gasoline Thermal Gasoline TCC Gasoline #1 L.S.R. #2 L.S.R. Denuded Casinghead #1 Reformate #2 Reformate Primary Tower OH Vol.c; 0.2 0.3 0.5 1 .8 1.6 3.7 0.9 1.0 2.8 MCD 000006190