Document kaad45ewn9YamwoBJdE2VoVkB

Am(*iCan HYGIENIC GUIDE SERIES ASSOCIATION tty Hygienic Guide Series 1,1,1-Trichloroethane (Methyl Chloroform) (Revised 1961) I. Hygienic Standards A. Recommended maximum atmospheric concentration (8 hours): 500 parts of vapor per million parts of air, by volume (ppm)1 1. Basis for Recommendation: Repeated administration to animals and human experience.1 s B. Severity of hazards: 1. Health: Moderate for acute exposure, but chronic exposures to concentra tions that are without acute effects are unlikely to produce injury. 1,1,1Trichloroethane is readily absorbed and excreted through the lungs.3 In acute exposure the most important toxic action is a functional depression of the central nervous system leading ultimately to respiratory failure. Ex periments with dogs have indicated that this material can induce ventricu lar arrhythmia similar to that pro duced by other chlorinated solvents.1 Animals exposed repeatedly to high concentrations exhibited some revers ible changes in liver histology, but they were not the severe effects asso ciated with carbon tetrachloride. Chronic exposures to 1000 ppm re sulted in moderate fatty degeneration of the liver but no liver necrosis or kidney injury. Growth depression oc curred at 650 ppm. No effects were seen from repeated 7-hour daily ex posures to 500 ppm. In controlled human ex|>osures to 500 ppm no effects other than slight, transient eye irrita tion were noted, but at 1000 ppm and above, mild eye irritation was experi enced by all subjects, and some became dizzy.1' 5 As with most solvents, derma titis might result from rei>eated skin contact, but 1, l, 1-trichloroethane is only poorly absorbed through the skin. Eye contact may result in pain and discomfort, but no impairment, of vision is likely. 2. Fire: 1,1,1-Triehlorocthane has no flash point when tested by standard ASTM procedures for the TAG Closed or Cleveland Ojien Cup tests. Some inhibited 1,1,1-trichloroethanes have been found to have explosive limits of 10% to 15.5% in air, but a high energy source is required to cause ig nition and, if the ignition source is removed, the vapor will not continue to burn.1 When inhibited products are evaporated to a small volume the resi due may flash. Thermal deeonqiosition products are very irritating and may be quite toxic, but voluntary over exposure to such materials (largely hydrogen chloride)8 is not likely. C. Short exposure tolerance: Beginning anesthetic effects, including incoordina tion, appear in some human subjects exposed to concentrations of 800 to 1000 ppm. They occur quickly in humans at concentrations of 2000 ppm or higher.2 Exposures to concentrations in excess of 30,000 (3% by volume) may be lethal in 5-6 minutes.7 D. Atmospheric concentration immedi ately HAZARDOUS TO LIFE: 30,000 ppm (3% by volume) based on animal experi ments.5' 7 II. Significant Properties Methyl chloroform is a volatile, colorless liquid with an aromatic "chloroformdikc" odor. The odor threshold may range from 20-100 ppm.* Chemical formula: Molecular weight: CHjCCh 133.42 Specific gravity: 1.3360 (2574C) Boiling point: 74.07C at 760 mm Hg Vapor.pressure at 125 mm Hg 25C: Solubility: Insoluble in water, but. miscible with alcohol, ether and most organic sol vents. SL 029465 December, 1GS1 At 25C and 760 mm Non-inhibited methyl chloroform should Hg: not be used in contact with aluminum 1 ppm of vapor: 0.00545 mg/liter because of. its reactivity with this 1 mg/liter of va 183 ppin metal. por: Gross skin contact should be prevented; Saturated air con 16.5% spectacles will usually offer adequate eye centration: protection. Relative density 4.6 (air = 1.0) of vapor: IV. Specific Procedures Relative density 1.6 (air = 1.0) of saturated air: A, First aid: Remove victim to an uncon taminated atmosphere and apply artificial III. Industrial Hygiene Practice respiration if breathing has stopped. Re A. Recognition: Methyl chloroform is used as a solvent and as a degreasing and cold cleaning agent. In many instances it has been substituted for the more toxic car bon tetrachloride. B. Evaluation of exposure: 1, Instrumentation: Instruments based on the Beilstein test such as the Davis Halide Meter9 and halide leak detec tors may be calibrated for 1,1,1-trichloroethane. Instruments employing measurement of the conductivity cf water which has absorbed the com bustion products of this material are available, and those using hydrogen flame ionization, while almost com pletely non-specific, can probably be move wet clothing and do not allow it to be re-worn until it is thoroughly dry. If eyes are contaminated they should be flushed with large amounts of water. B. Specific medical procedures: Treat symptomatically, watch the cardiac rhythm in any case of anesthesia pro duced by 1,1,1-triehloroethane, Oxygen therapy may be used, but epinephrine is contraindicated. Some indication of the extent of exposure may be obtained from an analysis of exhaled air.3 Urinary uro bilinogen may be of interest as a liver function test following acute excessive exposures.3 Recovery from a non-fatal acute episode can be expected to be com plete and prompt. used. Gas chromatographic, infrared, and mass spectrographic methods can V. References be used, especially when absolute identification is necessary. 2 Chemical Analysis: Direct combustion followed by absorption in a basic, re ducing solution and determination of the halide ion has been used success fully,10 as has adsorption on silica gel followed by thermal desorption and combustion.11 The method cf Fahy19 using isopropyl alcohol to desorb from silica gel, followed by alkaline hydrol ysis, is said to be applicable.11 A modi fied Fujiwara reaction may be used.10 Detector tubes by various manufac turers can probably be used, but each batch should be separately calibrated before use. C. Recommended control procedures; Concentrations to which men are re peatedly exposed should not exceed 500 ppm. General ventilation is usually suffi cient to maintain such control at room temperature unless large surfaces are wet with the solvent. Halogenated solvents should not be used where their vapors (in concentrations of a few ppm or more) will come into contact with very hot sur faces (such as near a welding operation) because toxic decomposition products 1. American Conference of Governmental Industrial Hygienists: Threshold Limit Values for 1961. Amer, Ind. Hyg. Assoc. J. 32: 325 (1961), 2. Torkelson, T. R., et al.: Amer. Ind. Hyg. Assoc. J. 19: 353 (1958). 3. Hake, C. L., et al.: .4M, 1 Arch, of Env. Health 1: 101 (1960) 4. Ronnick, B. R., et al.: Federation Proc. 8: 327 (1949). 5. Stewart, R. D., et al,: Amer. Ind. Hyg. Assoc. J. 22: 252 (1961). 6. Crummett, W, D., and V. A. Stenger: Ind. Eng. Chem. 48: 434 (1956). 7. Adams, E. M., et al.: AMA Arch, of Ind. Hyg. and Occup. Med. 1: 225 (1950). 8. The Dow Chemical Company, unpub lished data. 9. Schaffer, A. W., and H. R. Hoyle: Amer. Ind. Hyg. Assoc. J. 22: 93 (1961). 10. Jacobs, M. B.: Analytical Chemistry of Poisons, Hazards and Solvents, 2nd Edi tion. Interscience Publishers, Inc., New York (1949). 11. Peterson, J. E., et al.: Amer. Ind. Hyg. Assoc. Quart. 17: 429 (1956). 12. Fahy, J. P.: J. Ind. Hyg. and Toxicol. 30: 205 (1948). such as chlorine and hydrogen chloride may be formed. In such cases local ex 13. Rogers, G. W., and K. K, Kay: J. Ind. Hyg. and Toxicol. 29: 229 (1947), haust ventilation will be necessary. 14. Elkins, H. B., Personal Communication. SL 029466 Industrial Hygiene Journal BOO carbon tetrachloride is used, local exhaust ventilation will usually be necessary, and frequently the operation should bo iso lated (by total enclosure) from the gen eral work space. Concentrations to which men are repeatedly exposed should rarely or never .exceed 25 ppm nnd should not average over JO ppm. Air sampling is mandatory, and an automatic air moni toring system may be necessary to assure adequate control of vapor. Adequate respiratory protection should be provided for maintenance workers or in the event of spills or leaks. Gross skin contact should be prevented. Spectacles will usu ally offer adequate eye protection. IV. Specific Procedures A. First aid: Remove person to uncon taminated atmosphere and apply arti ficial respiration if indicated. Call a physician at once. Remove wet clothing and cleanse the skin with water or soap and water. Do not allow contaminated clothing to be reworn until it is thoroughly dry. Eye splashes should be treated with copious water irrigation. Any person sustaining an accidental high level exposure should be observed by a physician for several days, even if no symptoms have been noticed at the time of exposure. Nausea and vomiting occurring twenty-four hours or so after exposure may be the first sign of renal damage. B. Specific medical procedures: Employ ment should be restricted to persons free of a history of liver or kidney disorder, or of alcoholism. Treatment of acutely affected individuals should be directed toward restoring kidney and liver func tion. Hospitalization is essential. Oxygen therapy should be instituted if any anes thesia or cardiac failure has occurred. As with other chlorinated hydrocarbons, the use of epinephrino during any anes thetic phase may cause ventricular fibril lation. As the most serious sequelae of acute carbon tetrachloride exposure is toxic nephrosis (and death is directly related thereto), the use of an artificial kidney is indicated and may prove lifosaving. Some indication of the extent of exposure may be obtained from an anal ysis of exhaled air.1' V, References 1. American Conference of Governmental Industrial Hygienists: Threshold Limit Values for 1961, Amer. Ind. Hyg. Assoc. J. 22: 325 (1901). 2. American Standards Association-- Z37-17, 1957. 3. Adams, E. M., et al.: AMA Arch. Ind. Hyg. <fc Occ. Med. 6: 50 (1952), 4. Fassett, D. W. (Eastman Kodak Co., Rochester, New York) Personal Com munication. 6. The Dow Chemical Company, Unpub lished Data. 6. Sjoberg, Bcrtil: Svenska Kem Tid. (Swe den) 64: 63 (1952) (in English). 7. Crummctt, W. D., and V. A. Stenger: Ind. Eng. Chem. 48: 434 (1956). 8. Jacobs, M. B,: Analytical Chemistry of Industrial Poisons, Hazards and Solvents, 2nd Ed., Interscience Publishers, Inc., New York (1949). 9. Peterson, J. E., et al.: Amer. Ind. Hyg. Assoc. Quart. 17: 429 (1956). 10. Fahy, J. P.: J. Ind. Hyg. <fc Toxicol. 80: 205 (1948). 11. Rogers, G. W., and K. K. Kay: J. Ind. Hyg. and Toxicol. 29: 229 (1947). 12. Stewart, R. D., et al.: To be published: J. Am. Med. Assoc. 1,1,1-Trichloroethane (Methyl Chloroform) (Revised 1961) I. Hygienic Standards A. Recommended maximum atmospheric concentration (8 hours): 600 parts of vapor per million parts of air, by volume (ppm)1 1. Basis for Recommendation: Rotated administration to animals and human fexpericncc.1- * B. Severity of hazards: 1. Health: Moderate for acute exposure, but chronic exposures to concentra tions that are without acute effects V 510 December, 1961 are, unlikely to produce injury. 1,1,1Trichloroethane is readily absorbed and excreted through the lungs.* In acute exposure the most important toxic action is a functional depression of the central nervous system leading ultimately to respiratory failure. Ex]>criments with dogs have indicated that this material can induce ventricu lar arrhythmia similar to that pro duced by other chlorinated solvents.* Animals ex|x>scd repeatedly to high concentrations exhibited some revers ible changes in liver histology, but they were not the severe effects asso ciated with carbon tetrachloride. Chronic exposures to 1000 ppm re sulted in moderate fatty degeneration of the liver but no liver necrosis or kidney injury. Growth depression oc curred at 650 ppm. No effects were seen from repeated 7-hour daily ex posures to 500 ppm. In controlled human exposures to 500 ppm no effects other than slight, transient eye irrita tion were noted, but at 1000 ppm and above, mild eye irritation was experi enced by all subjects, and some became dizzy.'' `As with most solvents, derma titis might result from repeated skin contact, but 1,1,1-trichloroethane is only poorly absorbed through the skin. Eye contact may result in pain and discomfort, but no impairment of vision is likely. 2. Fire: 1,1,1-Trichloroethanc has no flash point when tested by standard ASTM procedures for the TAG Closed or Cleveland Ojxm Cup tests. Some inhibited 1,1,1-trichloroethanes have been found to have explosive limits of 10% to 15.5% in air, but a high energy source is required to cause ig nition and, if the ignition source is removed, the vajior will not continue to burn.' When inhibited products are evaporated to a small volume the resi due may flash. Thermal decomposition products are very irritating and may be quite toxic, but voluntary overexjjosure to such 'materials (largely hydrogen chloride)* is not likely.. C. Short exposure tolerance: Beginning anesthetic effects, including incoordina tion, appear- in some human subjects exposed to concentrations of 800 to 1000 ppm. They occur quickly in humans at concentrations of 2000 ppm or higher.* Exposures to concentrations in excess of 30,000 (3% by volume) may be lethal in 5-6 minutes.1 D. Atmospheric concentration immedi ately hazardous To life: 30,000 ppm (3% by volume) based on animal exjieri- ments.*-1 II. Significant Properties Methyl chloroform is a volatile, colorless liquid with an aromatic "chloroform-like" odor. The odor threshold may range from 20-100 ppm.* Chemical formula: ClhCCl, Molecular weight: 133.42 Specific gravity: l .3366 (25/4C) Boiling point: 74.07C at 760 mm Hg Vapor pressure at 125 mm Hg 25C: Solubility: Insoluble in water, but miscible with alcohol, ether and most organic sol vents. At 25C and 760 mm Hg: 1 ppm of vapor: 0.00545 mg/litcr 1 mg/liter of va- 183 ppm jior: Saturated air con 16.5% centration: Relative density 4.6 (air -- 1,0) of vapor: Relative density 1.6 (air - 1.0) of saturated air; III. Industrial Hygiene Practice A. Recognition; Methyl chloroform is used os a solvent and as a degreasing and coldcleaning agent. In many instances it has been substituted for the more toxic car bon tetrachloride. B. Evaluation of exposure; I. Instrumentation: Instruments based on the Beilstein test such as the Davis Halide Meter* and halide leak detec tors may be calibrated for 1,1,1-trichloroethane. Instruments employing measurement of the conductivity of water which has absorbed the com bustion products of this material are . available, and those using hydrogen flame ionization, while .almost com pletely non-specific, can probably be used. Gas chromatographic, infrared, and mass spectrographic methods can be used, esjiccially when absolute identification is necessary. SL 029468 Industrinl Ilygicnc Journal 611 2 Chemical A nali/sis: Direct, combustion followed by absorption in a basic, re ducing; solution and determination of the halide, ion has been used success fully,10 as has adsorption on silica gel followed by thermal desorption and combustion.11 The method of Faliy11 using isopropyl alcohol to desorb from silica gel, followed by alkaline hydrol ysis, is said to be applicable.14 A modi fied Fujiwara reaction may bo used.1* Detector tubes by various manufac turers can probably be used, but each batch should be separately calibrated before use. C. Recommended control procedures: Concentrations to which men arc re peatedly exposed should not exceed 600 ppm. General ventilation is usually suffi cient to maintain such control at room temperature unless large surfaces arc wet with the solvent, Halogenntcd solvents should not be used where their vapors (in concentrations of a few ppm or more) will come into contact with very hot sur faces (such as near a welding operation) because toxic decomposition products such as chlorine and hydrogen chloride may be formed. In such cases local ex haust ventilation will be necessary. Non-inhibited methyl chloroformshould not be used in contact with aluminum because of its reactivity with this metal. , Gross skin contact should be prevented; spectacles will usually offer adequate eye protection. IV. Specific Procedures A. First aid: Remove victim to an uncontaminated atmosphere and apply artificial respiration if breathing has stopped. Re move wet clothing and do not allow it to bo re-worn until it is thoroughly dry. If eyes are contaminated they should be flushed with large amounts of water. B. Specific medical procedures: Treat s3rmptomatically, watch the cardiac rhythm in any case of anesthesia pro duced by 1,1,1-triehloroethane, Oxygen therapy may be used, but epinephrine is contraindicated. Rome indication of tho extent of exposure may Ire obtained from an analysis of exhaled air.* Urinary uro bilinogen may be of interest as a liver function test following acute excessive exjTOsurcs.* Recovery from a non-fatal acute episode can bo expected to be com plete and prompt. V. References 1. American Conference of Governmental Industrial Hygienists: Threshold Limit Values for 1061. Amer. Ind. Iiyg. Assoc. J. 22: 325 (1961). 2. Torkelson, T. R., el al.: Amer. Ind. Hyg. Assoc. J. 19: 353 (1058). 3. Hake, C. L., et al.: AMA Arch, of Env. Health 1: 101 (1060). 4. Rennick, R. R., ef al.: Federation Proc. S: 327 (1940). 5. Stewart, R. D., ef al,: Amer. Ind. Hyg. Assoc. J. 22: 252 (1061). 6. Crummctt, W. D., and V. A. Stenger: Ind. Eng. Chem. 48: 434 (1956). 7. Adams, E. M., et al.: AMA Arch, of Ind. Hyg. and Occup. Med. 1: 225 (1950). 8. The Dow Chemical Company, unpub lished data. 9. Schaffer, A. W., and H, R. Hoyle: Amer. Ind. Hyg. Assoc. J. 22: 93 (1961). 10. Jacobs, M. B.: Analytical Chemistry of Poisons, Hazards and Solvents, 2nd Edi tion. Intcrscienec Publishers, Inc., New York (1949). 11. Peterson, J. E., et al.: Amer. Ind, Hyg. Assoc. Quart. 17: 429 (1956). 12. Fahy, J. P.: J. Ind. Hyg. and Toxicol. SO: 205 (1948). 13. Rogers, G. W., and K. K. Kay: J. Ind. Ilyg. and Toxicol, 29: 229 (1947). 14. Elkins, H. B., Personal Communication. Epichlorohydrin (l-Chloro-2,3-epoxypropane) I. Hygienic Standards A. Recommended maximum atmospherio concentration (8 hours): No official Tho Committoo wiohoo to ooknowlodoo thoooniotnnooof V. O* Poount in tho propnntion et thi* Hyiionlo Guido. value has been published. Five parts of vapor per million parts of air (ppm) by volume has been suggested on the basis of extensive animal exiierimcnts.*-* Such a level cannot be detected hy odor. B. Severity op hazards: SL 029469 Industrial ASSOCIATION HYGIENIC GUIDE SERIES Hygienic Guide Scies 1,1,1-Trichloroethane (Methyl Chloroform) (Revised 1961) I. Hygienic Standards A. Recommended maximum atmospheric concentration (8 hours): 500 parts of vapor per million parts of air, by volume (ppin)' 1. Basis for Recommendation: Repeated administration to animals and human experience.2 5 B. Severity of hazards: 1, Health: Moderate for acute exposure, but chronic exposures to concentra tions that are without acute effects are unlikely to produce injury. 1,1,1Trichloroethane is readily absorbed and excreted through the lungs.3 In acute exposure the most imixirtant toxic action is a functional depression of the central nervous system leading ultimately to respiratory failure. Ex periments with dogs have indicated that this material can induce ventricu lar arrhythmia similar to that pro duced by other chlorinated solvents.* Animals exposed repeatedly to high concentrations exhibited some revers ible changes in liver histology, but they were not the severe effects asso ciated with carbon tetrachloride. Chronic ex[>osures to 1000 ppm re sulted in moderate fatty degeneration of the liver but no liver necrosis or kidney injury. Growth depression oc curred at 650 ppm. No effects were seen from repeated 7-hour daily ex posures to 500 ppm. In controlled human exposures to 500 ppm no effects other than slight, transient eye irrita tion were noted, but at 1000 ppm and above, mild eye irritation was experi enced by all subjects, and some became dizzy.2' s As with most solvents, derma titis might result from repeated skin contact, but 1,1,1-trichloroethanc is only poorly absorbed through the skin. Eye contact may result in pain and discomfort, but no impairment of vision is likely. 2. Fire: 1,1,1-Trichloroethanc has no flash point when tested by standard ASTM procedures for the TAG Closed or Cleveland Open Cup tests. Some inhibited 1,1,1-trichloroethanes have been found to have explosive limits of 10% to 15.5% in air, but a high energy source is required to cause ig nition and, if the ignition source is removed, the vapor will not continue to burn.2 When inhibited products are evaporated to a small volume the resi due may flash. Thermal decomposition products are very irritating and may be quite toxic, but voluntary overexposure to such materials (largely hydrogen chloride)6 is not likely. C. Short exposure tolerance: Beginning anesthetic effects, including incoordina tion, apjicar in some human subjects exposed to concentrations of 800 to 1000 ppm. They occur quickly in humans at concentrations of 2000 ppm or higher.2 Exposures to concentrations in excess of 30,000 (3% by volume) may be lethal in 5-6 minutes.7 D. Atmospheric concentration immedi ately hazardous to life: 30,000 ppm (3% by volume) based on animal experi ments.5' 7 I. Significant Properties Methyl chloroform is a volatile, colorless liquid with an aromatic "chloroform-Iikc" odor. The odor threshold maj- range from 20-100 ppm.8 Chemical formula: CH3CCI3 Molecular weight: 133.42 Specific gravity: 1.3366 (25/4C) Boiling ixiint: 74.07C at 760 mm Hg Vapor pressure at 125 mm Hg 25C: Solubility: Insoluble in water, but. miscible with alcohol, ether and most organic sol vents. SL 029470 December, 1961 At 25C anil 700 mm Xon-inhibited methyl chloroform should Hg: 1 ppm of vapor: 1 mg/liter of vapor: Saturated air con- 0.00545 mg/liter 183 ppm 16.5 % not be used in contact with aluminum because of its reactivity with this metal. Gross skin contact should be prevented; sjiectacles will usually offer adequate eye centration: protection. Relative density 4,0 (air = 1,0) of vapor: IV. Specific Procedures Relative density 1.6 (air = 1.0) of saturated air: A. First aid: Remove victim to an uncon taminated atmosphere and apply artificial III. Industrial Hygiene Practice respiration if breathing has stopped. Re A. Recognition: Methyl chloroform is used as a solvent and as a degreasing and cold cleaning agent. In many instances it has been substituted for the more toxic car bon tetrachloride. B. Evaluation of exposure: 1. Instrumentation: Instruments based on the Beilstein test such as the Davis Halide Meter9 and halide leak detec tors may be calibrated for 1,1,1-trichloroethane. Instruments employing measurement of the conductivity of water which has absorbed the com bustion products of this material are available, and those using hydrogen flame ionization, while almost com pletely non-specific, can probably be move wet clothing and do not allow it to be re-worn until it is thoroughly dry. If eyes are contaminated they should be flushed with large amounts of water. B, Specific medical procedures: Treat symptomatically, watch the cardiac rhythm in any case of anesthesia pro duced by 1,1,1-trichloroethane Oxygen therapy may be used, but epinephrine is contraindicated. Some indication of the extent of exposure may be obtained from an analysis of exhaled air.5 Urinary uro bilinogen may be of interest as a liver function test following acute excessive exposures.5 Recovery from a non-fatal acute episode can be expected to be com plete and prompt. used. Gas chromatographic, infrared, and mass spectrographic methods can V. References be used, esix'cialiy when absolute identification is necessary. 1. American Conference of Governmental Industrial Hygienists: Threshold Limit 2 Chemical Analysis: Direct combustion followed by absorption jn a basic, re Values for 1961. Amer. Ind. Hyg. Assoc. J. 22: 325 (1961). ducing solution and determination of the halide ion has been used success fully,10 as has adsorption on silica gel followed by thermal desorption and combustion." The method of Fahy12 using isopropyl alcohol to desorb from silica gel, followed by alkaline hydrol ysis, is said to be applicable.14 A modi fied Fujiwara reaction may be used.12 Detector tubes hy various manufac turers can probably be used, but each batch should be separately calibrated before use. C. Recommended control procedures: Concentrations to which men are re peatedly exposed should not exceed 500 ppm. General ventilation is usually suffi cient to maintain such control at room temperature unless large surfaces are wet with the solvent. Halogenated solvents should not be used where their vapors (in concentrations of a few ppm or more) will come into contact with very hot sur faces (such as near a welding operation) because toxic decomposition products such as chlorine and hydrogen chloride may be formed. In such cases local ex haust ventilation will be necessary. 2. Torkelson, T. R., et al.: Amer. Ind. Hyg. Assoc. J. 19: 353 (1958). 3. Hake, C. L., et al.: AMA Arch, of Env. Health 1: 101 (I960) 4. Rennick, B. R., et al.: Federation Proc. 8: 327 (1949). 5. Stewart, R. D., et al.: Amer. Ind. Hyg. Assoc. J. 22: 252 (1961). 6. Crummett, W. D., and V. A. Stenger: Ind. Eng. Chem. 48: 434 (1956). 7. Adams, E. M., et al.: AMA Arch, of Ind. Hyg. and Occup. Med. 1: 225 (I960). 8. The Dow Chemical Company, unpub lished data. 9. Schaffer, A. W., and H. R. Hoyle: Amer. Ind. Hyg. Assoc. J. 22: 93 (1961). 10. Jacobs, M. B-: Analytical Chemistry of Poisons, Hazards and Solvents, 2nd Edi tion. Intersciencc Publishers, Inc., New York (1949). 11. Peterson, J. E., et al.: Amer. Ind. Hyg. Assoc. Quart. 17: 429 (1956). 12. Fahy, J. P.: J. Ind. Hyg. and Toxicol. 30: 205 (1948). 13. Rogers, G. W., and K, K. Kay: J. Ind. Hyg. and Toxicol. 29: 229 (1947). 14. Elkins, H, B., Personal Communication. SL 029471