Document EvpMLvJ6JvRvKp5wmBbnqkvq0

FILE NAME: Union Carbide (UC) DATE: 1956 DOC#: UC339 DOCUMENT DESCRIPTION: AMA - The Archives of Industrial Health - The Toxicity of Butyl Cellosolve Solvent The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. \>cs amxA t IO N S !X(: 7 T v c H i OF 'C INDUSTRIAL S U B JE C T S . . . QUARTERLY CUMULATIVE iX MEDICUS appears twice a volumes are cloth bound and periodicals for six months as ited on the publication. These volumes will be a convenient nel usive reference for current al literature. Invaluable for tioners, specialists, teachers, s, writers, investigators, stuand libraries. IWW -- MM. s ,.lrt v-, , .. _ The material on'this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. ! SAMPLER amples of contaminants lccurate interpretation of data de-. the knowledge of the volume of trough the filter, this instrument is ribution to industrial hygiene and personnel concerned with aerosoi s. The unit collects large samples' weighing and analysis. It is easy t is compact (7 )4" x x 15")!, only 131/2 pounds. * information on operation, filters,] on is given in our bulletin. Write: PLIANCES CO M PAN Y Avenue, Pittsburgh 8, Pa. 82 Branch Offices i ifates and Canada TABLE OF CONTENTS Volume 14 AUGUST 1956 N umber 2 ORIGINAL ARTICLES The Occupational Health Program of the Strategic A ir Command P age Lieut. Col. Alvin F. Meyer Jr., PE (MSC), U. S. A. F. . ........ 107 The Toxicity of Butyl Cellosolve Solvent C. P. Carpenter, Ph.D.; U. C. Pozzani, M S .; C. S. Weil, M .A.; / H. Nair III, M S .; G. A. Keck, B.S., and H. F. Smyth Jr., Ph.D., Pittsburgh............................................................................... 214 Cholinesterase A ctivity Levels Among Agricultural Workers L H. Fryer, M.B., B.S., and H. H. Williams, Ph.D., Ithaca, N. Y ........................................................................................ 132 Toxicity of Paradichlorobenzene R. L. Hollingsworth, M S .; V. K. Rowe, M S .; F. Oyen; H. R. Hoyle, B.S., and H. C. Spencer, Ph.D., Midland, Mich............... 138 Treatment of Methemoglobinemia A. F. Mangelsdorff, M. D., Bound Brook, N. 1.................................. 148 A Wind-Direction, Controlled A ir Sampler Elmer Robinson, M.A., Menlo Park, Calif................... ; ..................... 154 Studies of Ozone Toxicity Herbert E. Stokinger, Ph.D.; William D. Wagner, B.S., and Paul G. Wright, Cincinnati............................................................ 158 Toxicity Tests of D.ecaborane for Laboratory Animals /. L. Svirbely, Ph.D., and J. C. Roberts Jr., M.D., Pittsburgh.......... 163 Radiation Dosage from Breathing Radon and Its Daughter Products . Jacob Shapiro, Ph.D., Groton, Conn....................... ............. ........... 169 Threshold Limits for Pesticides W L. Ball, Ph.D., Ottawa, Ont., Canada............................................. 178 SPECIAL REPORTS Threshold Limit Values for 1956 .................................................................. 186 REGULAR DEPARTMENTS Abstracts from Current Literature............................................................... 190 B o o k s .......................................................................................................... 199 OCCUPATIONAL HEALTH NEWS South Dakota Inaugurates Rural Health C o n fe re n ce.................................. 201 (11) New York University Offers Post Graduate Occupational Health Course. .. 203 (13) 3:/ * Encyclopedia of Instrumentation Shown at Industrial Health Conference.. . 203/ (13) I Photographs from Philadelphia.......................'................... : ................... 204 (14) & Dr. Thomas F. Mancuso Chosen A . C . G . I. H. Chairman-Elect................... 205 (15) Advances in Industrial Toxipology for the Year 1955 ............................ .:. 206 (16). Summary of Meeting of Advisory Committee on Health Hazards in Uranium Mining and Milling Industry................................................... 212 (22) The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U OL % x;c;tf ofEutylCelLoL Soivent C. p. (CARPENTER, Ph.D. U. C. POZZANI, M.S. ' C- S.OiVEIL, M.A. J. H.^AIR 111, M.S. The most extensive publication u p j toxicity of butyl Cellosolve is the ser* S.^A.^ECK, B.S. three papers by Werner and his asso H. F. MYTH JR., Ph.D., Pittsburgh lhese workers compared the effects halation of five glycol ethers. In "mmmmmmmmmmmmmmmmimmmm...... .... mmmmmmmnm seven-hour inhalations by mice,butyl Butyl Cellosolve * (Q H 8OCH2CH2OH solve was found to have an L. C.50 o ---2-butoxyethanol) is a glycol ether with ex ppm. Death resulted as late as the f cellent solvent power for many of the resins week after inhalation. The usual sigi used m surface coatings. It is a useful toxic action was dyspnea. Inhalation of coupling agent, because it is miscible with lethal concentrations resulted in hemog water and with most solvents and many oils nuna. Changes were frequently seen ii / in surface coatings it imparts blush resist spleen, occasionally in the liver, lungs ance, gloss, and good flow-out. It is also kidneys In rats inhaling 320 ppm s employed in inetal cleaners, dry-cleaning hours a day, five days a week for five wi soaps, and hydraulic fluids. Butyl Cello- these workers3 found only light rever ?nJonh^ S a Spedfic gravity of -9019 at effects, characteristic of mild hemolytic / m c ' a oodmg point of 171.2 C, and emia. In dogs inhaling 400 ppm f0l a vapor pressure of 0.76 mm. Hg at 20 C. weeks, they4 found no indication of ht Vapor-saturated air at room temperature lyhc action, little damage to bone mar: has a concentration of the order of 1000 and little micropathologic effect afte ppm butyl Cellosolve. Its relative evapora- weeks of rest. Hemoglobin, red blood Oon rate is 1, m a scale in which that of count, and hematocrit were somewhat Ce oso ve is 5, butyl alcohol, 7, methyl duced, and some hypochromia, polydim Cellosolve, 8, xylene, 10, toluene, 40, and tophiha, and microcytosis were seen. Calc' acetone, 200. ^ ; , ' oxalate crystals were present in the u ' Previous Work and there was moderate retention of u it was concluded that butyl Cellosolve .Browning i summarized the scanty literaure upon the toxicity of butyl Cellosolve and mentioned isolated complaints of eye and nose irritation and headache. She found only one report of possible systemic effect m a workman. This man twice suffered attacks of hematuria while working with duces in rodents hemolysis of red bl cells, with resulting circulation of imma forms, but that dogs are resistant to . action. Butyl Cellosolve was the most to! of the five glycol ethers studied. Howev a concentration about two-thirds of satu tion was required to kill mice, and one-th, both butyl Cellosolve and butyl Carbitol. of saturation inhaled repeatedly caused oi Received for publication April 13, 1956 Mellon Institute of Industrial Research. Presented m part at the Annual Meeting o f the American Industrial Hygiene Association Phi a delphia, April 23-27, 1956 Cellosdve is a trade-mark name, the property o f Umon Carb.de and Carbon Corporation It designates an ether of ethylene glycol. 114 mild reversible changes in rodents and do The authors concluded that industrial ha* mg of the solvent is no great hazard be cause of its'low volatility. ,, 0 l! ^ basis of tIlis experimental work a threshold limit of 200 ppm has been widely accepted. On the other hand Browning,= atty, and Elkms 7 have each proposed that lower threshold limits would be more appro acetic acid in the urine extracts was made. Pre priate, the lowest value suggested being 25 ppm. In view of the increasing number and liminary work indicated that the extraction of the butoxyacetic acid from urine was completed with seven changes of ether per volume of aqueous liquid. A 16-hour extraction in a liquid-liquid variety of applications for butyl Cellosolve, extractor met this condition sufficiently. sive publication upon the lellosolve is the series of /emer and his associates, mpared the effects of in glycol ethers. In single work was undertaken to throw more light upon the nature of its action and to form a better estimate of the tolerated concentra tion. Demonstration of a Metabolite The R i valueX 100 of butoxyacetic acid under the conditions o f the method is 55-59. The lower limit of detection is 25 y, and the upper limit to read conveniently is 500 y. The aliquots of the alkaline wash spotted on the paper are adjusted to keep the quantity of acid within these limits. It is important that no more than 10 X of solution at a ions by mice,2 butyl Celloo have an L. C.50 of 700 ted as late as the fourth tion. The usual sign of Butyl Cellosolve is not amenable to ready identification and estimation in body fluids. It is a reasonable postulate that this glycol ether is oxidized in the mammalian body to time be applied to the paper at any one location. If necessary, repetitive applications, alternating with drying, may be employed to concentrate suf ficient material on the paper for analysis. In the analysis of urine samples a large amount of ex /spnea. Inhalation of near butoxyacetic acid. The development and use traneous material may show up on the paper as a ns resulted in hemoglobiere frequently seen in the y in the liver, lungs, and of the following analytical method verified this postulate. Reagents.--The reagents used consisted o f the long streak, but the upper limit of travel will be well below the butoxyacetic acid spot. The estimation o f the amount of butoxyacetic acid in a spot on the paper is made by comparison inhaling 320 ppm seven following: with spots containing known amounts of butoxy ays a week for five weeks, 5und only light reversible stic of mild hemolytic annhaiing 400 ppm for 12 ' id no indication of hemo- (1) Concentrated H 2SO1 (2) Ten per cent sodium tungstate, 100 gm. C. P. Na2W0.4H20 per liter distilled water (3) Van Slyke protein reagent8 . (4) Alcohol-ammonia chromatogram solvent, 99 ml. 95% EtOH + 1 ml. NH,OH, sp. gr. 0.9 acetic acid run simultaneously. The circumference and depth of color are two general criteria em ployed in making this comparison. A t the present time there is no commercial densitometer capable of making quantitative measurements with this type of chromatogram. Consequently we are damage to bone marrow, >athologic effect after 5 femoglobin, red blood cell .ocrit were somewhat re hypochromia, polychroma>cytosis were seen. Calcium vere present in the urine, 1t oderate retention of urea, that butyl Cellosolve pro . (5) Indicator, 50 mg. bromophenol blue + 200 mg. citric acid in 100 ml. distilled water (6) NH,,OH, sp. gr. 0.9 Procedure.-- (a) Blood: The proteins of a 5 ml. sample o f venous blood were precipitated with Van Slyke reagent. After filtration the filtrate or a suitable aliquot was extracted for 24 hours with ether. The ether extract was washed with 5 ml. NHuOH, and the alkaline solution was evaporated to dryness under an infrared lamp. The residue was taken up in 0.2 to 1.0 ml. distilled water, and obliged to accept the inaccuracy of a visual com parison. This unavoidable uncertainty reduces the quantitative significance of butoxyacetic acid esti mates. For rigorous identification a large amount of urine was collected from rabbits inhaling 400 ppm butyl Cellosolve for four hours. By means of a silicic acid column10 the metabolite was isolated from the urine. The melting point of the />-phenylphenacyl ester of the isolated metabolite was not depressed upon the addition of the same ester hemolysis of red blood 10 X portions were spotted on chromatogram paper. synthesized from an authentic sample of butoxy lg circulation of immature dogs are resistant to this losolve was the most toxic ethers studied. However, bout two-thirds of satura te kill mice, and one-third tied repeatedly caused only anges in rodents and dogs. rluded that industrial hansnt is no great hazard be/olatility. f this experimental work a 200 ppm has been widely e other hand Browning,5 The development of the chromatogram and the esti mation of butoxyacetic acid were carried out by the method described by Nair0 with use of the chromatogram solvent. (6) Urine: One milliliter of the sodium tung state solution was added to each twenty milliliters of the urine sample, and the mixture was then acidified with concentrated 11-80, against Congo red paper. After ether extraction the extract was washed with NHuOH several times. The alkaline washings were collected and diluted to 5-25 ml. in a volumetric flask, depending on the amount o f urine sampled. Ten lambda aliquots were spotted on the paper along with known amounts o f butoxyacetic acid as the ammonium salt and chromatographed. A t the end of the run the indicator was sprayed on the acetic acid.* Table 1 presents urinary butoxyacetic acid excretion by various animal species after inhalation of butyl Cellosolve. With the exception of the dogs, a correlation between the vapor concentration and bu toxyacetic acid excretion is suggested. Con current studies showed that most of the metabolite is excreted in 24 hours. We were unable to demonstrate butoxy acetic acid in the blood of animals inhaling butyl Cellosolve. It was found, however, in the blood of rabbits four hours after an intravenously administered dose of butyl s 7 have each proposed that phper, and an estimation of the amount o f butoxy * References 11 and 12. . 115 ) 8 CL T| A. M. A. ARCHIVES OP INDUSTRIAL H Cellosolve and in the urine collected during the 24 hours following the dose. Accordmgly it is reasonable to suppose that it is present in the blood of animals inhaling the gfycol ether but at a concentration too low for detection by the present method. erythrocytes were found in the urine ,, time. It was concluded that the hem j nuria was produced by in vivo hen! ' and that kidney injury was not respo| During the repeated inhalation sf described later, transient hemoglobj TAble 1.--Butoxyacetic A cid Found In was observed in rodents. It was ni Twenty-Pour-Hour Urine Samples from Animals Inhaling Butyl ' Cellosolve Vapor for Pour Hours during the first few hours of inhalatiol was not seen at all after the third dl inhalation. In a massive inhalatiol Animals, No. Species Approx. Vapor Concentration, Sex Ppm Estimated Butoxyacetio Acid, Mg. vapors almost saturated at room ted ture, the urine of female rats became ^ black with hemoglobin. The blood 2 Dog 1 Dog 1 Dog 6 Rabbits 2 Rabbits 27 R ats 17 Hats 12 Rats 12 Guinea pigs 12 Guinea pigs M 400 F 200 M 200 M 400 M 200 F 400 F 200 F 300 M - 200 M 100 55 42 100 80-302 12-23 14* 7* 1* 5* 4* globin concentration was halved by a si hour inhalation; the erythrocyte count! reduced even further, and the leuc count was raised to the same extent. In order to follow the course of in vivo , lysis, a test o f red blood cell osmotic fragility used. A series of stock solutions of dried sj chloride in double distilled water was prejf differing in concentration by 0.02% from to 0.52% and by 0.04% from 0.56% to 0, " ID1- One milliliter of each solution was placed Hemolytic Effects As early as 1938 this laboratory found that hemoglobinuria was evident in many separate clean 12 by 75 mm. test tube. One o f whole blood was dispensed into each test from a 22 gauge hypodermic needle held ; angle o f 45 deg. with the long bevel dowm rats dying after an oral dose of butyl Cello solve.' The report by Werner's group that rodents develop hemolytic anemia during in halation dictated that hemolytic effects should be studied in animals absorbing the Without delay the blood was thoroughly n with the saline by inverting each tube twice, tubes were held at room temperature for hours. Initial hemolysis was designated as highest saline concentration in which the sup< tant liquid first acquired a discernible yellow glycol ether. hue, and complete hemolysis as the highest To determine whether the hemoglobinuria was produced by cellular destruction in the kidney or by in vivo hemolysis, eight female rats inhaled 432 ppm and were killed in pairs at two-hour intervals. Kidney sections were studied microscopically; intact erythro cytes were sought in the urine, and hemin crystals were searched for by Teichmann's method.13 Slight cloudy swelling of the kidney was seen after two hours, and path ology had increased only to marked cloudy swelling of convoluted and loop tubules after eight hours. In vivo hemolysis was evident m two hours and severe after eight hours. Hemin crystals were found in the urine after four hours. Hemoglobinuria was evident in about three hours, but no intact 116 centration in which there was no visible Iaye intact cells on the bottom of the tube while liquid was a transparent deep-red color. Typical erythrocyte osmotic fragility ues for untreated rats are initial heniob in 0.48% saline and complete in 0.4C written here as 0.48-0.40. The test is rep ducible to within one tube in the concent tion series employed. Erythrocyte osmotic fragility values followed on six female rats during daily seven-hour inhalations of 200 butyl Cellosolve. Each day during inhaf; tion fragility rose as high as 0.68-0.48 an| returned to normal overnight. In a similar experiment, by the fourth day the erythrof cyte count had fallen by 50%, and thl hemoglobin level by 25%. A five-day reJj Four-HourTnlZZ Vsufyf^ll f!*" and Some Homologues m ?L Z e Pnf ^ * * B r Z r Z l e s Z r Groups o f S ix Fe,,,ale R ats tor comparison. The am t. ,, , 1 Chemical ' S / 0!vCe^ - ? rPyl CeJIosolvfi Jsoprppyl CellosolVe " B u ty Cellosolve Vinyl butyl C ellos)]TM ""' ?'lf>l5'n3 Ce)losoJTM_ | y f c o i ^ I050i- - : : Pheny] Cellosolve'. by.tc;:rw,,e;8i'26dr 2o ''vdsdi Lowest Concentration Causing Significant Fragility Ppm ^ Highest Concentration Causing No Fragility, Ppm 7?n ,, ' t0 6 Weeks of age and 2000 125 3000 62 62 32 62 62 32 32 lained fr? '< ? nd O1O2O5 203525 106002 TM (complete^ ? h T E ? E " 62 16 32' 32 16 b rid e? W d i ? ? ? CO In .his paper L. D r e f e ^ l ? " Quantitative Toxicity uselT these^stu2? ^ ' ' 1'116 S o l v e s s e r i a l sold undeT the" ? 7 CTM ercial during the year the w o * w a s ' J o n e ^ T rats were used ^ . i , done- Wistar d exclusively until 1942 and 118 ' S 2 it a w in X iiT e 'S * 1' ds"s' period. AAn?y dd"ev"ifattii"ona from- 4th " is noted in tahnl.r the pro a ehro,,,,,o8ica, ,isti"; o" ' I TW `tS '" V ' ml L D . ,, o f o.3: The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. w: S OF IN D U STR IA L HEALTH an Erythrocytes to cetate TOXICITY OF BUTYL CBLLOSLVE SOLVENT T a ble 4.--Single Oral Dose of L. D.sfs of Cellosolves In Vivo Response Year Species Weight, Sex Gm. 1 M l.-G m . la Water L . D.so and Range *. Fragility upon ition of B utyl olve Hemoglobinuria upon Inhalation of ButvJ Cellosolve * in t increase at mX4 hr. in t increase at os low as iOO !7 hr. int increase at mX7 hr. Seen a t 203 ppmX 7 hr. but not a t 107 ppmX7 hr. Seen a t 200 ppm but not a t 100 ppnX7 hr. N ot seen as high as 197 ppmX7 hr. ificant increase ppmXT hr.t ufleant increase ppmX7 hr.X2 N ot seen as high as 200 ppmX7 hr. Not seen as high as 605 ppmX7 hr. ificant increase ppinX8 hr.t ificant increase ppmX8 hr.t N ot seen a t 200 ppmX8 hr. Not seen a t 665 ppmXS hr. 1938 1936 1940 1951 1951 1952 1952 1953 1953 1954 1954 1954 1954 1954 1954 1 1954 1955 1955 1941 1944 1952-55 1953-54 1938 1938 *1952-55 1954 1954 Rat Guinea pig Rabbit Rat Rat Rat Rat Mouse Rat Rat Rat Rat Eat Rat Rat Rat Rat Rabbit Guinea pig Rabbit Rat Rat Rabbit Guinea pig Rat Rat Rat M * M +F M M F M * F M M F M F M F M F M M M +F M M F M M +F M F F 90-120 200-300 1500-3000 90-120 90-120 90-120 90-120 20-30 90-120 90-120 30-60 30-60 335-460 260-320 90-120 90-120 90-120 2700-3200 200-300 2000-3000 90-120 90-120 2000-3000 200-300 90-120 90-120 90-120 B u tyl Cellosolve 0.10 0.10 0.20 0.10 0 .1 0 0.05 0.05 0.10 0.05 0.05 0.05 Undiluted 0.05 M ethyl0C.1e0llosolve 0.25 0.10 0.10 Cellosolve 0.20 0.10 0.10 0.10 Undiluted 1.48 (1.15 to 1.91) gm./kg. 1.20 (0.96 to 1.50) gm./kg. 0.87 gm./kg. 2.0 (2.3 to 2.9) gm./leg. 2.3 (1.9 to 2.8) gm ./kg. 2.8 (2.4 to 3.3) gm .A g. 1.0 (1.2 to 2.1) gm ./kg. 1.23 (0.94 to 1.62)'gm ./kg. 1.9 (1.3 to 2.6) gm ./kg. 1.5 (1.4 to 1.9) gm ./kg. 3.U (2.6 to 3.4) gm ./kg. 2.3 (2.1 to 2.6) gm./kg. 0.56 gm./kg. 0.1>3 (0.38 to 0.75) gm ./kg. 2.4 (2.1 to 2.-7) gm./kg. 2.8 (2.2 to 3.7) m l./kg. 2.1 (1.4 to 3.1) gm ./kg. 0.32 (0.24 to 0.43) gm./kg. 0.95 (0.84 to 1.08) gm ./kg. 0.89 (0.65 to 1.23) gm./kg. 3.25 gm./kg. mean of 4 assays 3.4 gm./kg. mean of 2 assays 3.1 gm.'/kg. 1.4 gm ./kg. 5.u gm ./kg. mean of 4 assays 5.4 (4.9 to 5.9) gm ./kg. 5. (5.4 to 6.4) m l./kg. a then until June of 1952 th-Wistar found favor. All ve a like order of acute oral to certain chemicals chosen n. The acute oral test is a rocedure making use of nonto 6 weeks of age and 90 to ight, dosed at levels differing f 1.26 or 2.0 in a geometric iherman and Carworth rats l our own colony and mainme of weaning on Rockland lplete). The earlier Wistar .ys procured from commercial l's 14 tables for calculating the 'e dose (L. D.50) were used. L. D5o refers to the stallsd, most probable dosage level : in the death of 50% of the within a 14-day observation ieviation from the procedure bulation or text. Table 4 is listing of the acute oral toxr three Cellosolves. : an oral L. D.50 of 0.32 gm/ kg. and are the most sensitive to butyl Cello on methyl Cellosolve and Cellosolve are solve of the species tested. Mice and guinea given. Inspection of Table 4 will show the . pigs follow with a value of 1.2 gm/kg. order of decreasing acute oral toxicity to Young rats are four to five times more be butyl Cellosolve, methyl Cellosolve, and r resistant to single oral doses than are one- Cellosolve, with L. D,50's. of 2.5, 3.4, and , year-old adults, as evidenced by L. D.So 5.5 gm/kg. The guinea pig is not as dis values of 3.0, 2.4, and 0.56 gm/kg. for criminating as the rat, as values of 1.2, 0.95, male weanlings, 6-week-olds, and yearlings, and 1.4 gm/kg. for the three compounds in respectively. When given undiluted, instead like order indicate. Rabbits follow the rat of as a 5%, 10%, or 20% solution in water, order with L. D.50's of 0.32, 0.89, and 3.1 the 1954 L. D.50 value of 2.8 ml/kg. (2.5 gm/kg. gm/kg.) for females is almost identical with the 2.4 gm/kg. mean value for the males. Repeated Feeding.-- Five randomly dis tributed groups of five male and five female Sherman rats, about 6 weeks of age and Sluggishness, ruffling of coats, prostra weighing between 100 and 150 gm., were tion, and narcosis followed the administra fed Food Research Laboratory Diet 2-C in tion of dosages at or above the L. D.50. which was incorporated 2.0%, 0.5%, Autopsies performed on rats that died re 0.125%, 0.03%, and 0.0% butyl Cellosolve. vealed congested or hemorrhaged lungs, The latter group served as the control. The mottled livers, severely congested kidneys, diet consisted of 60 parts of freshly ground and hemoglobinuria. The latter symptom is whole wheat, 30.5 parts of dried whole milk, seen in. males on the 3.0 gm/kg. level but 1.5 parts of dried liver extract U.S.P., 5 'in females on levels as low as 1.5 gm/kg. parts of Type 50-B inactive dried brewer's Early death is attributed to narcotic effect, yeast, 2 parts of iodized salt, and 1 part of and delayed death to lung and kidney dam calcium carbonate. Statistical evaluation of age. the several criteria of response was made. For comparison, the means of several The 90-day feeding resulted in butyl iflosely agreeing, single oral dose rat assays Cellosolve intakes of 1.54, 0.31, 0.076, 119 \ 3S3 The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law, i , Pfe'ii!|, M iif ! &!all A -.M. A. A RC H IV E S OF IN D U ST R IA L H E A L T H r0n.0n1rA8,nfarn-%d,,f0i^.0-^g--m--'-/k--Og//d-maJy for th'e *rVe-Osp^/Ce.LcUtiVvte concentration groups. There were no deaths attributable directly to toxic action of the compound. The fact that rats survived 1.54 gm/kg/day means that their intake was . about three-fifths of an L. D.50 per day, or actually 54 L. D.50's in 90 days. In each fatality lung infection was found attended by kidney and liver pathology, such as is coincident with death caused by pneumonia in the rat. Appetite was not affected, and no pertinent micropathology was discovered. Blood was not found in pooled urine sam ples from the 2.0%, 0.5%, and control groups after three and six days on the diet either by the benzidine test or by spectrophotometric measurement for hemoglobin pigments. However, the mean weight gain of the surviving rats was significantly de pressed below that of the control group in the 2.0% concentration group. Liver weight as percentage of body weight was signifi cantly increased at both the 2.0% and 0.5% levels, and kidney weight at the 2.0% level. The highest level where significant devia tion from the control was within the usually accepted range of variation, and hence not chargeable to treatment, lies between 0.5% and 0.125% m the diet or between 0.31 and 0.076 gm/kg/day or at an intake be tween % and 1/32 of the L. D.50 per day. Parenteral Injection,-Undiluted butyl Cellosolve causes hemolysis of rat erythro cytes, as do all concentrations above 3% m 0.75% NaCl solutions. Tail vein injec tion of rats resulted in an L. D.50 of 0.38 gm/kg. for a 3% solution in 0.75% NaCl and 0.34 ml/kg. for undiluted compound. Mice were more toleran: as shown by an L. D.50 of 1.1 gm/kg. for the 3% solution. By ear vein in rabbits the L. D.go for the 3% solution was 0.50 gm/kg. and for the undiluted material 0.28 ml/kg. Methyl Cellosolve is hemolytic to rat erythrocytes in vitro in concentrations above 25% in 0.75% NaCl, and Cellosolve is hemolytic above a concentration of 18%. The comparative intravenous L. D.50's for rats in the dilutions mentioned are 2.7 gm/ kg. for methyl and 3.3 for Cellosolve, and for the undiluted compounds 2.2 (mean of two tests) and 2.4 ml/kg. The L. D.5o values by intraperitoneal injection of the undiluted compound in rats are as follows: butyl, 0.55; methyl, 2.5, and Cellosolve, 2.14 ml/kg. In rats, therefore, T able 5 .- L . D.Ns of Cellosohes and of Sodium Butoxyacdate by Injection Year 1951 1951 1953 1954 1955 1952 1953 1954 1954' 1954 1953 1954 1955 1954 120 Species Rabbit Rat Mouse Rat Rabbit Rat Rat Rat Rat Rat Rat Rat Rat Rat Weight, Sex Gm. Concentration, 1 M l.= Gm. L. D.so and Range 2500-3000 170-230 15-35 90-120 2500-3000 B utyl Cellosolve (Intravenous) 0.03 in 0.75% NaCl 0.03 in 0.75% NaCl 0.03 in 0.75% NaCl Undiluted Undiluted 0.50 (0.38 to 0.65) gm./kg. 0.38 (0.29 to 0.50) gm./kg. 1.13 gm./kg. 0.34 (0.30 to 0.38) ml./kg. 0.28 m l./kg. * F 90-120 (Intraperitoneal) Undiluted 0.55 (0.32 to 0.94) m l./kg. M ethyl Cellosolve F 90-120 (Intravenous) 0.25 in 0.75% NaCl F 90-120 F 90-120 Undiluted 2.70 (1.04 to 3.77) gm./kg. 2.14 (1.54 to 2.99) ml./kg. Undiluted 2.30 (1.87 to 2.83) ml./kg. F 90-120 (Intraperitoneal) Undiluted 2.46 (1.88 to 3.23) m l./kg. Cellosolve F 90-120 (Intravenous) 0.18 in 0.75% N aCl F 90-120 Undiluted 3.25 (2.48 to 4.26) gm./kg. 2.38 (1.92 to 2.97) m l./kg. F 90-120 (Intraperitoneal) Undiluted 2.14 (1.54 to 2.99) m l./kg. Sodium Butoxyacctate F 90-120 0.0(3Inintra0v.7e5n%ouNs)aCl 0.78 (0.59 to 1.02) gm./kg. VES o p in d u s t r ia l h e a l t h ^jfOXIClTY OF BUTYL CELLOSOLVE SOLVENT 111 tbe diet or betweefi 0.31 gm/kg/dav or at an intake be f e e Cellosolves fall in the same order of all had hemoglobinuria. Similarly in I95I nd 1/32 of the L. D/ 0 per day. il Injection--Undiluted butyl causes hemolysis of rat erythro all concentrations above 3% faCl solutions. Tail vein injec- resulted in an L. D.50 of 0.38 a 3% solution in 0.75% NaCI l/kg- for undiluted compound, more tolerant as shown by an -1 gm/kg. for the 3% solution ,n rabi^ts the L. D.50 for ihe was 0.50 gm/kg. and for the terial 0.28 ml/kg. ellosolve is hemolytic to rat m vitro in concentrations above 5% NaCI, and Cellosolve is *ve a concentration of 18%. ^decreasing toxicity by the parenteral and fepral routes. Sodium butxyacetate with an l/L. D.50 of 0.78 is included in Table 5 libecause it is a demonstrable metabolite of il^utyl Cellosolve. W Skin-Penetration.--Male albino New Zeafiand strain rabbits, 3 to 5 months of age, Jpvere immobilized during a 24-hour skiri ||fcpntact period. Thereafter, the Vinylite feheeting used to retain the dose in contact pwith the clipped skin of the trunk was rejgmoved, and the animals were caged for the gtemainder of the 14-day total observation period. The rabbits were procured locally ja n d maintained on Rockland rabbit ration. I ^ e ir s 14 tables for calculating the L. D.50's pivere used. Table 6 presents the results. . four of six rabbits succumbed when dos 1 at 0 56 ml/kp For comparison, the rabbit skin penetrtion L. D.50 for methyl Cellosolve is 1.1 ml/kg. and for Cellosolve, 3.6 ml/kg. bL simple inunction the L. D.60 of Cellosolve I ^ 16.3 ml/kg. In effect this means that rabbi? 10 can tolerate four times as much Cellosolv] when it is gently rubbed into the uncover^ skm in one application as they can when th. compound contacts ihe skin under an imj pervious sheeting for 24 hours. The samfe e relationship holds for butyl Cellosolve, a l 2 it has an L. D.50 of 2.0 ml/kg. by inunctioi ^<D and about 0.45 ml/kg. under imperviou sheeting. Rapidity of skin penetration in rabbit itive intravenous L. D.5fl's for dutions mentioned are 2.7 gm/ T able 6.--Skin Penetration Toxicity of Celtosolves yl and 3.3 for Cellosolve, and ; HvYcar Species Weight, L. D 0 and Range o> uted compounds 2.2 (mean of Sex Concentration (14-day Observation Period) d 2.4 ml/kg. 'so values by intraperitoneal he undiluted compound in rats :: buty!>0.55; methyl, 2.5, and 14 ml/kg. I,, rats, therefore, gjN946 r-19im47 1951 - 1954 L1954 ^ 1955 M - '1955 Rabbit Rabbit Rabbit Rabbit Rabbit Rabbit Rabbit Rabbit Butyl 2.0 to 3.0 2.7 to 3.7 2.0 to 3.0 2.5 to 3.0 2.5 to 3.0 2.5 to 3.0 2.5 to 3.0 2.7 to 3.2 Cellosolve Undiluted Undiluted Undiluted Undiluted Undiluted Undiluted Undiluted U nd ilu ted t 0.56 (0.48 to 0.64) ml./kg. 0.56 m l./kg. killed 10/10 0.56 m i./kg. killed 3/6 0.56 m l./kg. killed 4/6 0 5 m l./kg. killed 6/8 0.5 m l./kg. killed 5/8* 0.45 (0.?5 to 0.82) m l./kg. 2.0 m i./kg. killed 2 of 4 vacetnte by Injection it'OIl, 3m. losolve ous) o NaCI o NaCI o KaCl cdI nea}) ci U- 13.4 and Range 0-50 (0.38 to 0.65) gm /k e S.1I '38> 0.55 (0.32 to 0.94) llll./kg. 2.70 (1.94 to 3 77) gni /k e 2.14 (1.54 to 2 .9 9 )m l./k f.' 2.30 (1.87 to 2 83) m l./kg. 2.40 (1.88 to 3.23) m l./kg. ea!) acetate is) NaCI 3.25 (2.48 to 4.20) gm./kl? 2.38 (1.92 to 2.97) ml /kg'. 2.14 (1.54 to 2.99) m i./kg. 0.78 (0.59 to 1.02) gni./kg. 1944 W3M' 1944 1944 . Rabbit Rabbit Rabbit M M ethyl Cellosolve ' 2.5 to 3.0 Undiluted Cellosolve 2.3 to 3.3 Undiluted 2.3 to 3.3 U n d ilu ted ! W -. 1 i m irs>a!i Others. 24 hours. t Uncovered, rubbed into skin by gentle massage. 3.34 (1.26 to 3.43) ml./kg. 3.56 (2.24 to 5.G6) ml /kg. 16.3 (13.2 to 20.2) m l./kg. J: ^-50 for rabbits by skin penetra tion of undiluted butyl Cellosolve as deter . mined in 1945 was 0.56 and in 1955, 0.45 7 mlAg- Extreme congestion of the kidney, hemoglobinuria, pale liver, and engorged sPEen were noted upon autopsy of the rabbits that succumbed. In 1947, 10 rabbits were dosed at the L. D.50 (0.56 ml/kg.), and they all died within 48 hours of the application. These rabbits weighed about 3.0 kg. and were procured from Rockland Farms. Hemo globinuria was a common finding. Again in 1948 butyl Cellosolve was applied to six rabbits from our regular local supplier; three of the six survived 0.56 ml/kg., but is demonstrated by the fact that a 4-hour and a 24-hour application of 0.5 ml/kg. of butyl Cellosolve under impervious sheeting produced comparable mortality ratios, name ly, 5 of 8 and 6 of 8. Increased erythrocyte osmotic fragility of rabbit blood one hour after a three-minute skin contact period with 0.56 ml/kg. butyl Cellosolve on 4.5% of skin area graphically demonstrates passage through the skin. Range-Finding Inhalations. -- Many of these data collected on inhalation toxicity were to guide the selection of concentration levels for repeated inhalation tests. Known concentrations were obtained by the meth ods described in the next section. The early 121 ^ * '* static exposures were made in an apparatus O" m u S T R U l HEALTH ,,,e r r " at TM> m p S " ;inng' tthheeWeenrtiirSeatpUerraito1d. with the. chemical dr- innnat rm temPerature would approach 1000 ppm for butyl Cellosolve, 5000 for Cellosolve, and 8000 for methyl Cellosolve The concentrated vapor results of 1951 were achieved by passing air 2j e xp^ecctteeddtTo dapVp3roPOacr'h 3sSat^uration.d- Per minute through a fritted glass disc im- Repeated Inhalation Methods --Inhala " " y rate, g,,i,,ea p f e T able 7.- -Range-Finding Inhalation Studies on Cellosolves Year Species WGeimgh. t, Sex 1940 1940 1940 1942 1951 1951 1951 1951 1951 1951 1951 1951 1951 1951 1952 1952 Rat Rat Rat Guinea pig Rat Rat Rat Rat Rat Rat Rat Rat Rat Rat Rat Rat VO-95 75-85 88-106 300-350 120-140 120-150 120-130 120-130 100-120 120-130 120-160 140-160 92-104 88-98 380-500 250-330 M M +F 1944 Rat 1944 Rat 1944 Rat 1952 Rat 1952 Rat 1952 Rat 115-160 120-140 125-150 150-175 120-140 125-160 1945 Rat 3945 Rat 1945 Rat 1945 Rat 1952 Rat 1952 Rat 90-130 85-105 125-160 95-115 130-240 120-185 M +F M M +F M +F M +F M +F C .V .-' `Concentrated- vapor generated a t room temperature. Concentration, Ppm B utyl Cellosolve U'Yr ^circulator X 'Y ' 5 ec.irculator '-'.v. Recirculator cC..vV.. c.v. 800 800 500 500 500 250 250 125 375 375 M ethyl Cellosolve 2000 2000 2000 C.V. 8000 4000 Cellosolve 4000 4000 2000 2000 C.V, C.V. No. tt ExxpTn r"- s MRr a?tionty uria 1X9 1X4 1X2 1X4 1X8 1X8 1X8 1X4 1X8 1X4 2X8 4X 8 6X8 6X8 1X8 1X4 1X2 1X4 1X8 1X4 1X8 1X4 4 /6 2/6 0/6 1/6 01//66 03//66 0/6 1/6 3 /6 1/5 0/6 0/6 11/13 23/23 6/6 1/5 0/6 2/6 4 /6 1/6 6/6 3 /6 3 /6 0/6 10/12 1/12 mersed in 50 ml. of the liquid held at room emperature. Judging by mortalities after ght J ours< concentrated vapor was somewhat less than enn * i F wdb solve 800 PPm butyl Cello- that one ermre> it is again apparent hat one-year-old rats are more susceptible than young actively growing rats, as was the rase with single oral doses. At 375 ppm 6- aft6r SeVCn hours>while the PPPPmC TThhee rreaptSea!teUd7 e`Vxepdoseu'grehst, h80Uhrosurast 5p0e0r tJo^leartaeteT2s5o0 pt0pmPrffoirCt90thdaatysr.ats w^ l d not TaMe 7 lists the results. Methyl Cello solve and Cellosolve are not drastically diferent from each other in single inhalation; both are less tox,c than butyl Cellosolve. he vapor pressures are such that satura- 122 monkeys took pIace in chambers ^ capacity from 200 to 7900 liters ( , f t b e ). Solvent ,,as delivered , , i c o u t h e y means of a displacement-type pro portioning pump, originally described by: Insh and Adams/ 6 or by a motor-driven' syringe into an electrically heated tubular^ -ryrex evaporator, such as described by Carpenter and co-workers. The resulting vapor-air mixtures were conducted to thJ chambers under slight negative pressure a` a rate to provide a theoretical turnover ol chamber air every three to five minutes. -Pood and water were withheld from a animals during seven-hour exposure perio' five days .each week. Rats and mice wer maintained on Rockland rat diet (com? The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. f OF INDUSTRIAL HEALTH W B m rO X IC IT Y OF BUTYL CELLOSOLVE SOLVENT temperature would approach ' butyl CellosoEe, 5000 for 8000 for methyl Cellosolve. apor, as prepared, would be broach saturation. . . ihalation Methods-- Inhalauinea pigs, mice, dogs, and plete), X guinea pigs on Rockland rabbit Jration supplemented with kale, dogs on Ejjriskies meal, and monkeys' on Okatie J ^ F a rm s |{ diet. The rodents had food and Kuw ater ad libitum when not inhaling vapor, ?-#.and the large animals were fed once daily. Healthy animals whose weights differed level. Erythrocyte osmotic fragility tests were performed on some of the smaller animals. The concentrations o f butyl Cellosolve vapor in the exposure chambers wire checked four times daily with a portable 50 cm. Zeiss interferometer The instrument was calibrated against a bichromate Oellosolves No. Exposures M ortality X Hr. Ratio Hemo globin uria jfykss than two standard deviations from the ||igroup mean were distributed at random P'among the exposure and control groups. JyControl groups were carried each time for fr^rodents but not for the dog and monkey oxidation method, adapted from the procedure de scribed by Werner and Mitchell" ; 5 ml. 0.33 N K2Cr30 ,-a n d 5 ml. concentrated H,SO,, Sp gr 1.84, were added to a 2 liter Florence flask fitted, with a 29/42 standard taper female joint and stoppered with a matohing male joint sealed to a 1X9 4/6 1X4 2/6 1X2 0/6 1X4 1X8 VVO6 4- 1X8 0/6 1X8 3/6 1X4 0/6 1X8 1X4 0/6 1/6 44-- 2X8 3/6 -f- 4X8 6X8 1/5 0/6 44-- 6X8 0/G 1X7 1X7 11/13 23/23 4+ MSTiPy. exposures because of limitations on housing IHT space. .a-. animals were weighed weekly and at completion of the study. The livers and kidneys of the rodents were removed and | weighed after disposition of the animals by T section of the cervical cord and suspension yby the tail for approximately five minutes. Dogs and monkeys received an overdose of sodium pentobarbital intravenously. Por stopcock. The flask was evacuated to a pres sure such that approximately a liter of the ex posure atmosphere would he sampled when the stopcock was opened. For use, the stopcock was attached to a sampling tube placed centrally in the exposure chamber and opened until the flask pres sure returned to atmospheric. A sample of the exposure atmosphere was read simultaneously in the interferometer. The flask was shaken for 15 minutes on a wrist-action shaker, heated on a steam bath for 90 5 minutes, cooled, and then 250-300 ml. distilled 1TO and 3 gm. KI were 1X8 6/0 1X4 1/5 1X2 0/6 1X4 1X4 2/6 4/G + 1X4 1/0 1X8 6/6 1X4 3/6 1X8 3/6 1X4 0/0 1X8 1X4 10/12 1/12 4- -e in chambers ranging in >to 7900 liters (a 6 '/?. ft. as delivered at a constant a displacement-type pro originally described by or by a motor-driven iectrically heated tubular such as described by workers.16 The resulting were conducted to the ght negative pressure at i theoretical turnover of three to five minutes, were withheld from all n-hour exposure periods . tions of the following tissues of dogs and added. The contents were titrated with 0.05 N v,: monkeys were taken for histological exatnaj,.. nation: adrenals; appendix vermiformis; gall bladder; gonad; heart; intestine; kid neys; liver; lung; pancreas; spleen; stom- NasSaOs with the addition of 4 ml. o f 1% starch solution near the end-point. A blank determina tion was made on room air. Burette readings were converted to parts per million by means of the following equations; ; ach; thyroid; urinary bladder; uterus, and mg. butyl Cellosolve/Iiter air = any other abnormal tissue. Usually only the liver, lung, and kidney of the rodents were studied. Erythrocyte and leucocyte counts, hemo globin levels, erythrocyte osmotic fragility, and hematocrit values were followed on the dogs and monkeys, using blood taken immediately upon removal from exposure. Sulfobromophthalein sodium (Bromsulphalein) retention time, sedimentation rate, (ml. NaaSdh blank -- ml. Na2Sj0j sample) x 0.227 liters of air sample ppm butyl Cellosolve = mg./l. X 206.9 Repeated Inhalations by Rats and Guinea Pigs. Groups of rats and guinea pigs in haled various concentrations of butyl Cello solve 7 hours a day, five days a week for a total of 30 days. The initial weight of the Sherman rats was between 140 and 190 gm., and the guinea pigs weighed 435 to 580 gm. icterus index, blood urea nitrogen, and Table 8 summarizes the results. The most plasma fibrinogen levels were measured by notable finding was the greater susceptibility conventional methods. When high-level of female rats at 432 ppm. The 15 females groups yielded negative results, the tests died within three days, while 3 males sur were omitted at lower exposure levels. An vived 30 inhalations. erythrocyte permeability test by the method of Boatman and Moses17 was performed Gross pathology in the rats consisted of once on the dogs exposed at the 200 ppm congestion and hemorrhage of the lungs t Rockland diets are prepared by the Arcady and congestion of most of the abdominal Farms Milling Co., Chicago. viscera. Histological examination confirmed I k. Rats and mice were ckland rat diet ( com I Fnskies meal is a product o f Albers Milling Co., Kansas City, Mo. II Okatie Farms, Pritchardville, S. C. the gross findings and revealed cloudy swelling of the liver. Hemoglobinuria was observed in most of the rats at the 432 and 123 The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. . A. M. A. ARCHIVES OF INDUSTRIAL HEALTI T able 8.-- Response of Rats and Guinea P igs to Inhalation o f Butyl Cellosolve Vapor For Thirty Exposures, Seven Hours per Day, Five Days per Week Animals, No. Bats 15 (F) 15 (M ) 15 <F) 15 (M ) 14 (F) 14 (M ) 15 (F) 15 (M ) 15 (F ) Guinea pigs 10 (M ) 10 <M) 10 (M ) 10 (M ) 10 (M ) Concentration, Mortality Ppm Mean Ratio Body YVt. Kidncv W t. Liver YVt. 432 15/15 432 12/15 314 15/15 203 0/15 N 0 > 203 0/14 N 0 > 107 0/14 N > > 107 0/15 N > > 54 0/15 N N N 54 0/15 N N N 494 2/10 N > N 376 1/10 < > N 203 0/10 N > N 107 0/10 N N N 54 0/10 N N N Gross Pathology + + 4* 0 0 0 0 0 0 + 40 0 0 Micro Erythrocyte Hemoglo- I pathology Fragility* binuria I + + 4 + + + + 1 + | 0 0 o 0 + o a 4- 0 + 0 0 0 0 o fl N Values not statistically different from controls (p is equal to or>0.05). > Values statistically higher than controls (p < 0.05). < Values statistically lower than controls (7XO.O0). + Substance or response present. 0 Substance or response absent. -- Test not performed. * These values obtained from extra animals not included in the m ortality ratios. 314 ppm levels, but in only 1 of 15 males of guinea pigs, groups of 10 males wer^ and 10 of 15 females subjected to 203 ppm. exposed 30 days to 494 and 376 ppm. Ir This condition was not observed in the addition, groups of six males and six fe| surviving animals after the second day of males were exposed at these levels to detect exposure. Erythrocyte osmotic fragility, any sex difference in susceptibility. The proportional to the vapor concentration, was mean weights of the males varied from 435 found in rats immediately after a seven- to 580 gm., and the females from 351 tc hour inhalation of 107 ppm or any higher 369 gm. concentration, and after some of a series of Significant tissue damage, which coni 30 inhalations of 54 ppm, with values for sisted of lung congestion and cloudy swell! fell females usually exceeding the males. In ing of the convoluted and loop tubules olj almost every case these high fragility values the kidneys, was found only in the two returned to normal after overnight rest. fatalities at 494 ppm and the one at 376 There were no statistically significant ppm. The mean weights of both groups of findings as regards mortality, body weight animals fell slightly by the third exposure]! change, or tissue damage in the rats exposed but only at the 376 ppm level were thejl a* at the 203, 107, and 54 ppm levels 7 hours significantly below the controls after 30 ex-f| per day for 30 days. However, significant posures. A significant elevation in kidney increases in kidney and liver weights as weight as percentage of body weight oc| percentage of body weight were observed curred in both groups The mixed groups ' -j . in the rats at 203 and 107 ppm levels. The showed essentially the same mortality ratios highest concentration level where deviation as did the all-male groups and evidenced no from the control is within the usually ac significant difference in sex response. The cepted range of variation, and therefore not above data indicate that guinea pigs foleratd related to exposure, is between 54 and 107 a concentration below 203 ppm but above ppm. Guinea pigs were more refractory. 107 ppm butyl Cellosolve. The latter con-1 The only criterion of response which dif centration was without statistically signifi-| fered significantly from the controls at the cant deviation from controls in any of thef i;. 203 ppm level was an increase in kidney criteria of toxic response followed in thisj weight as percentage of body weight. To study. characterize more completely the response Repeated Inhalation by Mice: Groups! 124 w >' OF INDUSTRIAL HEALTH if Butyl Cetlosolve Vapor Days per Week . Micro>athology - + 4* 4* 0 0 0 0 0 0 Erythrocvte Fragility* 4+ + 4 4+ + + + Hemoglohi mu ia . + + + + 0 0 0 0 4- 0 0 + 0 0 0 0 0 0 0 0 0 0 0 groups of 10 males were ys to 494 and 376 ppm. In )s of six males and six fe>osed at these levels to detect ence in susceptibility. The >f the males varied from 435 ; id the females from 351 to issue damage, which concongestion and cloudy swellvoluted and loop tubules of -as found only in the two 4 ppm and the one at 376 n weights of both groups of ghtly by the third exposure, e 376 ppm level were they low the controls after 30 exniificant elevation in kidney :entage of body weight oc groups. The mixed groups illy the same mortality ratios :ale groups and evidenced no rence in sex response.' The cate that guinea pigs tolerate below 203 onm but above Cellosolve. The latter conwithout statistically signififrom controls in any of the c response followed in this halation by Mice: Groups . TOXICITY OF BUTYL CELLOSOLVE SOLVENT of 10 mature male C3H mice, obtained from after the third exposure, but increased the Shalom Research Farms, Mars, Pa., erythrocyte osmotic fragility occurred at all were exposed without controls to 494 and concentrations. The increase appeared to 376 ppm butyl Cellosolve for 30 days, with be as great after the first exposure as it resultant mortality ratios of 7/10 and 2/10. was after the 89th exposure, and in all in For more definitive data, .groups of 70 stances was normal after a 17-hour rest. male mice were exposed to metered concen The response of mice and guinea pigs at trations of 400, 200, and 100 ppm. Serial 400 ppm for 30 days was similar, but the -examinations were made on 15 mice from former are much more sensitive from the each group after 30 and 60 exposures, on standpoint of osmotic fragility. 10 more after 90 exposures, and on groups Repeated Inhalation by Dogs: A female of 11 to 16 after 90 exposures followed by mongrel dog inhaling 617 ppm butyl Cello a 42-day rest period. Ten mice from each solve died after a total of 13^4 hours of group were used for serial determination of exposure during two days. Emesis and ex erythrocyte osmotic fragility on blood ob treme weakness were observed on both days. tained by section of the cervical vessels and Autopsy revealed moderate congestion of cord. Table 9 lists the results. the kidneys and lungs but no hemoglobi Statistically significant alteration of liver nuria. Findings of this sort would be ex '~oo weights occurred in the mice exposed to 400 pected following a narcotic death. Death ppm for 30, 60, and 90 days but not in occurred so quickly that there was no oppor- T abce 9.--Response o f Male Mice to Repeated Seven-Hour Inhalations o f Butyl Cellosolve Vapor Animals, Concentration, Exp. M ortality Body No. Ppm Days Ratio W t. Kidney Liver W t. W t. Gross Pathology Micro Erythrocyte Hemoglo pathology Fragility binuria {5 TO 2: C. 15 U24 30 0/15 N N N * 0 0 0 o 15 111*5 60 0/15 N N N 0 0 4- 0 10 112*5 90 0/10 N N N 0 0 4- 0 o 16 * 112*5 90* 0/16 N N N 0 0 0 0 15 203*4 30 0/15 N N N 0 15 200*6 60 0/15 N N > 0 10 201*6 90 0/10 N N N 0 14 201*6 90* 0/10 N N N 0 0 0 4- 4- 0 4- + 0 0 0 15 396*10 30 0/15 N N < 0 0 -f 4- 15 399*9 60 0/15 < N > 0 0 4- 4* E o 10 401*9 90 0/10 N N > 0 0 4- 4- 11 401*9 90* 0/11 N N N 0 0 0 0 8Q . * Plus 42 days rest before examination. N Values not statistically different from controls (p>0.05). 05 > Values statistically higher than controls. < Values statistically lower than controls. 4- Substance or response present. <D 0 Substance or response absent. those rested 42 days after 90 exposures. tunity to repeat preexposure blood chem Why liver weights were increased after 60 istry and hematological tests. days but not after 30 or 90 days at 200 ppm A male and a female basenji hybrid in is not understood. No significant mortality haled 385 ppm repeatedly. Hematological 0TO5 or gross pathology was observed. Histolog tests were performed daily on both dogs, E ical examination of kidneys from 80 mice with blood chemistry on the male after 26 <15 from various exposure levels revealed'no and 27 exposures. Analysis of the urine of significant tissue changes. the male for possible butoxyacetic acid ex Table 10 shows that the number of mice cretion was performed after the 25th expo which had bloody urine immediately after sure. The female died after 8 days and the exposure was proportional to th vapor con male after 28 days of exposure. Both dogs centration. No hemoglobinuria was found showed similar symptomatology and physio- 12S ! A. M. A. ARCHIVES OF INDUSTRIAL i f f " T able 10 --Erythrocyte Osmotic Fragility Values and Hemoglobinuria in Mice A fte r Inhalation of Butyl Cellosolve Vapor ' Approx. Concentration, Ppm 100 100 100 100 100 100 200 . 220000 200 200 400 400 400 400 400 400 0.0 (Air controls) N o. of 7-H r. Exposures 1 2 3 29 88 89 1 2 3 29 89 1 2 3 29 88 89 1 2 3 88 88 89 89 Fragility Im m ediately A fter Exposure 0.60-0.52 0.64-0.52 0.64-0.52 0.60-0.52 0.60-0.52 0.60-0.52 0.68-0.64 * -- 0.68-0.62 0.68-? 0.60-0.50 0.68-0.58 0.75-0.60 0.68-0.60 0.68-0.60 -- 0.60-0.50 0.50-0.42 0.50-0.42 -- -- -- 0.46-0.38 0.54-0.46 F rag ility 17 H r. A fter E xposure 0.52-0.44 __ __ 0.52-0.44 0.52-0.44 0.48-? -- -- 0.50-0.42 0.54-0.40 0.50-0.42 -- -- 0.50*0.42 0.52-0.38 -- _ -- -- 0.50-0.40 0.52-0.40 -- R atio of g M ice W hich E x e B loody U rin e Tmifij A fter E xpostn 0/60 0/60 0/60 __ -- 9/60 0/60 * 0/60 -- 26/60 4/59 0/59 __ -- 0/60 0/60 0/60 --_ __ -- logical response, although toxic manifesta tions appeared more slowly in the male. Loss of weight, transitory increase in erythrocyte osmotic fragility, nasal and ocular infection, . generalized weakness, apathy, anorexia, and increased leucocyte count were observed in both animals. Emesis occurred in the female several times during the first four days of exposure. A significant decrease in erythrocyte count and hemoglobin level occurred in the male. It was of note that the fragility value of the male reached a maximum of 0.54-0.42 in 7 days and fell to 0.32-0.20 after 27 days, demonstrating that all susceptible erythro cytes had been removed from this animal's blood stream. Analysis of a 16-hour urine sample from the male after the 25th ex posure indicated the presence of 55 mg. of butoxyacetic'acid. The only positive results obtained from the blood chemistry tests were elevated plasma fibrinogen levels .of 1.75 and 2.26 gm/100 ml. in the male dog after the 26th and 27th exposures, respec tively. These values were several times higher than the accepted normal value of 0.52 gm/100 ml.19. It might be presumed that these elevated fibrinogen values were caused by dehydration in the dog prior to 126 death, but this possibility was elim' by the relatively low hemoglobin com tions and erythrocyte counts. The striking findings at autopsy consis moderate to severe congestion and rhage of the lung, congestion ,,of the! and congestion of both kidneys in tiff male. Histological examination cons the gross observations, with the addf discovery of a severe subcapsular h | rhage in one adrenal in the female dog Male and female basenji litter, mates! exposed to a mean concentration o f ppm butyl Cellosolve for 31 days. Hel logical tests were performed weekly! blood chemistry tests immediately aft 15th, 22d, and 29th exposures and b| the 28th exposure. An erythrocyte plj ability test was performed on the nel the last day of exposure, using ra|j dine.17 The corneas were inspected the aid of fluorescein dye before the exposure and after the 31st. There slight evidence of toxic effect in the after 31 days of exposure. ErythreP osmotic fragility values of the- male mcreased slightly, and leucocyte counts doubled. The fragility value of the female also rose slightly, while the erythrocyte 5- OF INDUSTRIAL HEALTH emoglobinuria in Mice 'apor agility Hr. wter posure 2-0.44 -- -- 2-0.44 2-0.44 8-? -- -- D-0.42 4-0.40 0-0.42 --- -- SHJ.42 2-0.38 _ -- -- 3-0.40 2-0.40 - R atio of Mice Which Excreted Bloody Urine Immediately After Exposure 0/60 0/60 0/60 -- -- 9/60 0/60 0/60 -- -- 26/60 4/59 0/59 -- -- 0/60 0/60 0/60 -- -- -- s possibility was eliminated ly low hemoglobin concentra- throcyte counts. The more igs at autopsy consisted of ' were congestion and hemor- ung, congestion of the liver, . i of both kidneys in the fe- gical examination confirmed rvations, with the additional t severe subcapsular hemor- drenal in the female dog. nale basenji litter mates were f mean concentration of 200 1 osolve for 31 days. Hemato- rere performed weekly, and , y tests immediately after the : 29th exposures and before ' ure. An erythrocyte perme- j 3 performed on the next to ! )f exposure, using radioio- a orneas were inspected with | irescein dye before the first 1 after the 31st. There was ; of toxic effect in the dogs : of exposure. Erythrocyte ty values of the male in ly, and leucocyte counts fragility value of the female ltly, while the erythrocyte TOXICITY OF BUTYL CELLOSOLVE SOLVENT count and hemoglobin level fell slightly.' excreted 30 mg. of butoxyacetic acid in a f The erythrocyte permeability of both dogs 48-hour period, but only trace amounts were I was numerically higher than that for similar found from the male and from the female | control dogs, but the increase was not sta later in the inhalations. At autopsy tubercu- 1 tistically significant. Blood chemistry tests losis in both animals was found--sufficient | revealed no abnormal value. At autopsy to obscure possible effects of the inhalation. | there appeared to be some slight capillary A rhesus monkey inhaled 210 ppm for J engorgement or breakdown in the lungs of 30 days. After th fourth inhalation the |j both dogs, but these findings were not con erythrocyte osmotic fragility was found to firmed by histological examination. Flu be elevated. It returned to normal over- 1 orescein staining of the eyes indicated no night. For the balance of the exposure I damage. Butoxyacetic acid was present to period this cycle was substantially repeated. 1 the extent of 100 and 42 mg. in 16-hour After 30 inhalations erythrocyte count and | urine samples from the male and the female hemoglobin level had been reduced to half | after the 14th exposure. their initial values. After 14 inhalations | Male and female wire-haired terrier litter plasma fibrinogen was found to be 1.22 gm / J mates, 8 months of age, were exposed for 100 ml., four times the normal concentra- 1 90 days to a mean concentration of 100 tion. Emesis occurred four times during | ppm. Routine blood chemistry tests were the latter part of the period. At autopsy f performed on both dogs before the first the organs appeared normal except for a exposure and after the 90th. Hematocrit suggestion of pulmonary tuberculosis. | values and icterus indices were determined There was nothing noteworthy in the histo- | in addition to the regular hematological pathology. | studies performed weekly. Analysis for urinary butoxyacetic acid was done on speci mens from the male and the female. The Human Inhalations | The human inhalation studies are sum- %| dogs did not appear to be affected 'appre marized in Table 11. In the first trial two | ciably by exposure to 100 ppm, although men and six rats simultaneously inhaled t some alterations were observed in the hema 113 ppm butyl Cellosolve for four hours | tological picture. There was a transitory in a 1250 cu. ft. room. None of the erythro- J doubling of the leucocyte count in both dogs cyte osmotic fragility values of the men f midway in the 90-day period. The female's deviated from their preexposure values, I count returned to the preexposure level, but while the values for the rats rose appreci- > that of the male remained approximately ably. Human symptoms, which were secretly 't SO% higher at the end of the period. An recorded, included nasal and ocular irrita- | appreciable drop in the hematocrit values tion, disagreeable metallic taste, slight in- I of t-he male, from 43.0% packed red cells crease in nasal mucous discharge, and -.t before the first exposure to-34.5% after 90 occasional eructation. Four to six hours | exposures, was observed. Twenty-four- after exposure one man complained of feel- hour urine samples from the male and fe ing as though he had "smoked too many } male dogs contained 100 and 94 mg. of cigarettes," although none had been used. ( butoxyacetic acid. - About a year later the same two men, r Repeated Inhalation by Monkeys: Two Subjects C and P, and one woman, Subject \ monkeys inhaled 100 ppm butyl Cellosolve N, inhaled 195 ppm butyl Cellosolve for j' for 90 days. Erythrocyte osmotic fragility two 4-hour periods separated by a 30- | rose on several occasions, higher in the minute recess for lunch. Exposure took female than in the male, but returned to place in a 6)4 ft. cube (7900 liters) through normal by the end of the period. Erythro which air was drawn at the rate of approxir cyte counts fell briefly but returned to mately 1300 liters per minute. Blood normal. After the 42d inhalation the female pressure and pulse rate were determined for The matenal on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyri m . si. su K .^ tu p '^ U SU U blK lA L tit T able 11.--Responses of Humans to Butyl Cellosolve Vapor Concentration, H r. of Ppm Exposure Chamber 195 S 278 cu. ft. chamber - 113 4 1250 cu. ft. room 98 8 278 cu. ft. chamber Subject N C P C P L K. W C Age, Erythrocyte Blood Sex Yr. Fragility! Pressure! F 24 0.44-0.36 98/64 M 44 0.42-0.30 114/74 M 34 0.42-0.36 114/71 M 44 0.42-0.36 M 34 0.42-0.36 - F 34 0.40-0.36 116/70 F 24 0.42-0.36 108/68 M 37 0.40-0.36 120/84 M 44 0.42-0.36 112/74 Pulse K atet 75 83 74 86 80 84 76 * Milligrams per 24-hour sample. t These values taken near end oi the exposure periods. --Tests not performed. . J Sample analyzed twice to verify low range reported. each subject three times during the expo sure day, and erythrocyte osmotic fragility tests were determined four times. Urin alyses for glucose and albumin were con ducted the following morning, and the butoxyacetic acid levels determined on urine samples collected during the 24 hours fol lowing completion of the exposure. Subjects N and P excreted considerable amounts of butoxyacetic acid in the 24-hour period following exposure, but Subject C, for some unknown reason, excreted only trace amounts of the metabolite. The remainder of the tests on humans were negative, al though the erythrocyte fragility values of three female rats, concurrently exposed, in creased steadily during the exposure. The privately recorded response of all three sub jects included immediate irritation of the nose and throat, followed by ocular irrita tion and disturbed taste. The woman, who excreted the largest amount of metabolite, also acquired a headache which lasted about 24 hours. . Based on the response of the humans in haling 195 ppm for eight hours, the woman appeared to be more sensitive than either of the two men. All agreed that 195 ppm butyl Cellosolve was too high for comfort when continually breathed. Other volun teers inhaled a concentration of approxi mately 100 ppm for eight hours. Three of these subjects, two women and one man between 24 and 37 years of age, had had no previous contact with the vapor. Subject 128 C was included because only trace a of urinary butoxyacetic acid were after the 195 ppm inhalation, and the ity of this result required a check. T ppm inhalation took place 20 days aft! 195 ppm experiment and included m the tests" performed previously,'excep urinary glucose and albumin in the ht and erythrocyte osmotic fragility ir were omitted. The mean concentrati butyl Cellosolve was 98 ppm,' and the chamber temperature, 26.2 C, with ext of 23.0 and 29.2 C. The only objective ing of significance was the urinary exc of butoxyacetic acid. Following the sure, Subject C, who had not excretenificant quantities of the metabolite the 195 ppm exposure, eliminated 7f in 24 hours. The urinary butoxyaceti level of the other three subjects was si to that found at the 195 ppm exposure, subjective response of the humans ini 98 ppm may have been almost as gre that elicited at the 195 ppm level. T1 male subject (L) apparently expert greater distress during and after exp than did the others. Subject L expert emesis after seven hours in exposure several times the following day, while jects K and W complained of headaches next day. The former subject stated high temperature often caused emesis that she was convinced that the pres episode was caused by the relatively chamber temperature in the afternoon. OF IN D U STRIAL H EALTH solve Vapor cytc Blood ltyt Pressuret 1.36 98/64 .36 114/74 h36 114/71 1.36 _ .36 - -.36 116/70 -.36 108/68 .36 120/84 .36 112/74 Pulse Ratet Urinary Butoxy, tcetic Acid' 75 300 - 83 19-381 6-12J 74 175 _ ' _ - - 86 183 80 100 84 250 76 75 because only trace amounts oxyacetic acid were found >m inhalation, and the validt required a check. The 100 took place 20 days after the ment and included most of med previously,'except that and albumin in the humans osmotic fragility in rats The mean concentration of was 98 ppm, and the mean iture, 26.2 C, with extremes C. The only objective findce was the urinary excretion acid. Following the expo- who had not excreted siges of the metabolite after cposure, eliminated 75 mg. e urinary butoxyacetic acid r three subjects was similar the 195 ppm exposure. The ase of the humans inhaling ve been almost as great as he 195 ppm level. The fe_) apparently experienced during and after exposure ers. Subject L experienced en hours in exposure and : following day, while Subomplained of headaches the former subject stated that i often caused emesis and onvinced that the present sed by the relatively high iture in the afternoon. It . TOXICITY OF BU TYL CELLOSOLVE SOLVENT remains uncertain whether or not these phenomena should be charged to inhalation of vapors. Comment . Butyl Cellosolve has been a commercially available solvent for at least 30 years'. Since 1945 the generally accepted hygienic stand ard of inhalation has been 200 ppm, and little or no attention has been directed to the ease with which the liquid penetrates the skin, although by this route it is a mod erately toxic material. Based upon the re sponse of experimental animals to repeated inhalation of butyl Cellosolve, one might suppose 50 ppm or even less to be an appro priate hygienic standard of inhalation. In view of these facts, it is not idle to inquire why there have been no reported instances of human injury, beyond one uncertain ob servation of hematuria. One factor undoubtedly is low volatility. The hygienic standard of inhalation has been one-fifth of saturation at ordinary tempera tures. It is most unlikely that any workman actually inhales this much for more than a brief period during a working day. This factor is not important in the case of skin penetration. In the handling of hydraulic fluids there is no doubt that skin penetra tion accounts for more absorption than does inhalation. A second factor is the nature of injury from repeated inhalation of low concentra tions of butyl Cellosolve. It is a slow drain upon the erythrocyte producing organs. With the existing great capacity of the bone marrow to replace erythrocytes, so long as only those in the circulation are affected, a relatively enormous, long-acting drain is re quired to result in any clinical symptoms or in any actual injury. There is a third, and apparently a more important, factor explaining why there have been no reported injuries. Butyl Cellosolve is one of the few industrial materials to which the human is more resistant than are the usual experimental animals. A greater contact with butoxyacetic acid is required to cause osmotic fragility of human red blood cells than is required to hemolyze rat, mouse, rabbit, dog,' or monkey erythrocytes. Inhalation of 200 ppm for eight hours does not result in fragile human erythrocytes, but as little as 62 ppm for four hours does affect rat cells. For this reason a hygienic standard of inhalation for butyl Cellosolve should not be based solely upon repeated inhalations by susceptible animals. The current hygienic standard of 200 ppm for inhalation of butyl Cellosolve appears, on the basis of evidence and experience, to be low enough to prevent humarj injuries. How ever, discomfort will be experienced by some human subjects inhaling this concen tration for eight hours. In this instance, 200 ppm refers to the time-weighted aver age concentration throughout a working day. Detectable injury from high concen trations apparently cannot occur in less than an hour at saturation--1000 ppm and dis comfort from -this concentration will make prolonged voluntary inhalation unlikely. Summary and Conclusions Inhalation of a high concentration of butyl Cellosolve, of the order of 500 ppm, half of saturation, for several hours may injure by respiratory tract irritation and narcosis, with slighter damage to kidney and liver. Death may be prompt, due to nar cosis, , or it may be delayed several days, due to pneumonitis added to kidney injury. Butoxyacetic acid is a metabolite of butyl Cellosolve in the rat, rabbit, guinea pig, dog, rhesus monkey, and man. It can be estimated semiquantitatively in the urine. This excretion is the first detectable evidence of absorption of butyl Cellosolve. Men in haling 100 ppm for 8 hours excrete 100 to 200 mg. of butoxyacetic acid within the next 24 hours, with considerable individual variation. Butyl Cellosolve, and to a greater extent its metabolite, butoxyacetic acid, increases the osmotic fragility and presumably the mechanical fragility of the erythrocyte. This action is greatest in the rodents--rats, mice, rabbits. It is less in the guinea pig, the dog, the rhesus monkey, and the human. Other 129 The materia! on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law. The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law A. M. A. ARCHIVES OF INDUSTRIAL HEAL glycol ethers act similarly, with quantitative differences. Increased fragility leads to de struction of erythrocytes and excretion of their hemoglobin in the Urine as such or as hemin. The destroyed erythrocytes are promptly replaced by new cells, and if in sult is prolonged, eventually immature forms may enter the circulation. Repeated exces sive inhalation of butyl Cellosolve by rodents and dogs was found to result eventually in reduction of the blood hemoglobin concen tration and the total erythrocyte count to the point of anemia. Increased osmotic fra gility of erythrocytes was not found in man during inhalations in which simultaneously exposed rats were so affected. It was found in vitro with human erythrocytes, and hence is to be expected after inhalation of some concentration higher than the 200 ppm to which men did not respond. In repeated inhalations by animals the significant effects were lung irritation, cloudy swelling of renal loop and convoluted tubules, heavy kidneys, low hemoglobin and erythrocyte counts, hemoglobinuria, and fragile erythrocytes. Females were suscept ible to lower concentrations than were males. Rats were not affected by 30 seven-hour inhalations of 54 ppm, guinea pigs by 30 inhalations of 100 ppm, dogs by 90 inhala tions of 100 ppm. Mice, rats, and monkeys inhaling 100 ppm for 90 days had only fragile erythrocytes. Humans are more re sistant to hemolytic anemia, the injury char acteristic of small animal response to in halation of low concentrations of butyl Cellosolve. Therefore, a safe working con centration for .humans cannot properly be based solely upon rodent response. During an eight-hour inhalation of 200 ppm butyl Cellosolve there was no objective effect upon three humans, although butoxyacetic acid in their urines proved con siderable absorption. Subjectively the concentration was judged too high for com fort, with eye, nose, and throat irritation evident. During eight hours at 100 ppm four humans likewise showed a similar qualitative response. The present work interprets the accepted 130 hygienic standard of 200 ppm for inh; tion of butyl Cellosolve as a concentrt which rodents cannot tolerate, which slightly injurious to dogs, and which appe not to injure humans. Our human w was not sufficiently extensive to demonsti that 200 ppm will not eventually result some degree of hemolytic anemia. Beca of this prudence dictates that 100 ppm a more appropriate level to maintain workroom atmospheres. Even at this k there may be occasional complaints of ( comfort from extremely sensitive persor No matter how butyl Cellosolve may er the circulation, it is a relatively toxic i terial. It penetrates the skin readily. I to its low volatility, there are many ap cations where prevention off excessive p longed skin contact is more important health than is prevention of inhalation. REFERENCES 1. Browning, E .: Toxicity o f Industrial Org Solvents, London, H. M. Stationery office, I p. 3S5. 2. Werner, H. W .; Mitchell, J. L .; Mi J. W., and von Oettingen, W. F .: Acute Tox: of Vapors of Several Monoalkyl Ethers Ethylene Glycol, J. Indust. Hyg. & Tox 2 5 :157-163, 1943. ; 3. Werner, H. W .; Nawrocki, C. Z.; Mite J. L .; Miller, J. W., and von Oettingen, W. Effects of Repeated Exposures of Rats to Va; o f Monoalkyl Ethylene Glycol Ethers, J. In<i Hyg. & Toxicol. 2 5 :374-379, 1943. j 4. Werner, H. W .; Mitchell, J. L .; Mi J. W., and von Oettingen, W. F .: Effects of 1 peated Exposure of Dogs to Monoalkyl Ethy Glycol Ether Vapors, J. Indust. Hyg. & Tox 25:409-414, 1943. 5. Browning, E .: Toxic Solvents, Lon Edward Arnold & Co., 1953, p. 136. 6 Patty, F. A , editor: Industrial Hyg and Toxicology, New York, Interscience 1 lishers, Inc., 1949, Vol. 2, pp. 965-966. 7. Elkins, H. B .: Chemistry of Indus Toxicology, New York, John Wiley & Sons, 1950, pp. 229-230. 8. Peters, J. P., and Van Slyke, D. Quantitative Clinical Chemistry, Baltimore, liams & Wilkins Company, 1932, Vol. 2, p. 66. 9. Nair, J. H., I l l Paper Chromatography some Alkoxy Acids, Analyt. Chem. 25:1912, 19 10. Ramsay, L. L , and Patterson, W. ' Separation and Determination of the Strai Chain Saturated Fatty Acids Cs to C by Parti OF INDUSTRIAL HEALTH ard of 200 ppm for inhala- Celiosolve as a concentration cannot tolerate, which is us to dogs, and which*appears humans. Our human work ntly extensive to demonstrate will not eventually result in f hemolytic anemia. Because ice dictates that 100 ppm is priate level to maintain in lospheres. Even at this level occasional complaints of dis- extremely sensitive persons, aw butyl Cellosolve may enter , it is a relatively toxic ma trates the skin readily. Due itility, there are many appli- prevention of excessive pro- ntact is more important for r prevention of inhalation. 1 REFERENCES ! E.: Toxicity o f Industrial Organic * , H. M. Stationery office, 1953, . ; i. W.; Mitchell, J. L .; Miller, ; .. let tingen, W. F .: Acute Toxicity j , Several Monoalkyl Ethers of I. , J. Indust. Hyg. & Toxicol. \ W. ; Nawrocki, C. Z. ; Mitchell, W., and von Oettingen, W. F. : led Exposures of Rats to Vapors hylene Glycol Ethers, J. Indust. 25:374-379, 1943. I. W. ; Mitchell, J. L. ; Miller, )ettingen, W. F. : Effects of Reof Dogs to Monoalkyl Ethylene pors, J. Indust. Hyg. & Toxicol. E. : Toxic Solvents, London, C o, 1953, p. 136. A., editor: Industrial Hygiene New York, Interscience Pub , Vol. 2, pp. 965-966 . B. : Chemistry of Industrial York, John Wiley & Sons, Inc., P., and Van Slyke, D. D. : cal Chemistry', Baltimore, WilZompany, 1932, Vol. 2, p. 66. , III : Paper Chromatography of ds, Analyt. Chem. 25:1912, 1953. L., and Patterson, W. I. : Determination of the Straight<atty Acids C5 to CMby Partition TOXICITY OF BUTYL CELLOSOLVE SOLVENT ' Chromatography, J. A. Off. Ag. Chem. 31:139- 1S0, 1948. 11. Shriner, R. L., and Fuson, R. C .: Systematic Identification of Organic Compounds, Ed. 2, New York, John Wiley & Sons, Inc., .1945. 12. Hann, R. M .; Reid, E. E., and Jamieson, G. S .: Phenacyl, />-Chlorophenacyl and p-Bromo- phenacyl Esters of Some Higher Fatty Acids, J. Am. Chem. Soc. 5 2 :818-820, 1930. 13. Hawk, P. B.; Oser, B. L., and Summerson, W. H .: Practical Physiological Chemistry, Ed. 13, New York, Blakiston Company (Medical Division of McGraw-Hill Book Co., Inc.), 1954. 14. Weil, C. S .: Tables for Convenient Calcula tion of Median-Effective Dose (LDS0 or ED,) and Instructions in Their Use, Biometrics 8:249 263, 1952. 15. Irish, D. D,, and Adams, E. M .: Apparatus and Methods for Testi.ng Toxi.city' of Vapors, P|>' Indust. Med., Indust. Hyg Sect. 1 :l-5, 1940. | 16. Carpenter, C. P. ; Smyth, H. F., Jr., andfj Pozzani, U. C. : Assay oi Acute Vapor Toxicity $ and Grading and Interpretation of Results on 9 6 1 Chemical- Compounds, J. Indust. Hyg. & Toxicol, 31:343-346, 1949. . 17. Boatman, J. B., and Moses, C. : Sole of J, Erythrocyte in Blood Iodine Transport Using-! Radioiodine I" 1, Am. J. Physiol. 164: 783-785,1 1951. | 18. Werner, H. W-, and Mitchell, J. L. : Deter- | mination of Monoalkyl Ethers of Ethylene Glycol, 1 Indust. Eng. & Chem., Analyt. Ed. IS :375-376, , 1943. I 19. Albritton, E. C., editor : Standard Values in y . Blood, Philadelphia, W. B. Saunders Company, j1 1952, p. 96. ( t' 6 . it tr f I dl I I 131 The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright law.