Current Intelligence Bulletin 29: Glycidyl Ethers
October 12, 1978
DHHS (NIOSH) Publication Number 79-104
The National Institute for Occupational Safety and Health (NIOSH) would like to inform the occupational health community of the possibility of adverse effects to the testes and the hemopoietic (blood forming) system in workers exposed to glycidyl ethers.
During development of a NIOSH criteria document on glycidyl ethers, a pattern of research findings emerged which indicates that some of the glycidyl ethers may be capable of producing testicular atrophy and hemopoietic abnormalities in various species of laboratory animals. Additionally, after the issuance of the June 1978 NIOSH criteria document, a 1957 study was released to NIOSH reporting testicular atrophy in laboratory rats exposed to n-butyl glycidyl ether. While none of the individual research reports are conclusive with respect to the ability of glycidyl ethers to produce permanent changes to the testes or hemopoietic system in laboratory animals, some of the changes observed may act as predisposing factor to systemic problems. NIOSH is not aware of any studies investigating the possibility of occurrence of testicular atrophy or hemopoietic abnormalities occurring in humans exposed to glycidyl ethers. The possibility of these effects occurring in humans is reason for concern. Therefore, NIOSH requests that any information regarding testicular atrophy or hemopoietic abnormalities observed in workers exposed to glycidyl ethers be reported to the NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies, Industry-Wide Studies Branch, Medical Section, Telephone: (513) 684-3593.
NIOSH advises strict adherence to the detailed recommended occupational standard described in the glycidyl ethers criteria document. Particular attention should be given to appropriate medical surveillance in order to detect testicular atrophy or hemopoietic abnormalities in exposed workers. NIOSH requests that producers, distributors, users, professional associations, and unions transmit this information to their customers, employees, associates and members.
Glycidyl ethers are synthetic compounds characterized by the group and find their major use as components of epoxy resin systems. The “diglycidyl ether of bisphenol A” has been a traditional basic active ingredient of epoxy resins; other glycidyl ethers are frequently incorporated into epoxy resin systems as reactive diluents. The epoxy group of the glycidyl ethers reacts during the curing process and glycidyl ethers are therefore generally no longer present in completely cured products. Epoxy resins containing glycidyl ethers are used in a variety of applications including protective coatings, reinforced plastics, as well as bonding materials and adhesives.
Much occupational exposure to glycidyl ethers results from the use of proprietary or trade name products which do not disclose the presence of toxic agents in their formulations. This complicates efforts to take appropriate precautionary measures for the prevention of occupational disease. For example, unrecognized hazardous situations can occur where protective coatings containing epoxy resins are sprayed, thereby facilitating the inhalation of even non-volatile materials, and where there is skin contact with epoxy resins containing glycidyl ethers.
Data collected by the NIOSH National Occupational Hazards Survey (NOHS) have been used to estimate the number of people having potential occupational exposure to glycidyl ethers, as well as in identifying the industries in which the exposures occur. Pertinent data from NOHS are presented in Tables 1 and 2. NIOSH has previously estimated that approximately 1,000,000 workers are exposed to epoxy resins.1
Table 1. NIOSH National Occupational Hazard Survey Estimates of Occupational Exposure to Glycidyl Ethers
|Glycidyl Ether||Estimated Number of Workers
|Diglycidyl Ether of Bisphenol A||36,000|
|n-Butyl Glycidyl Ether||13,000|
|Phenyl Glycidyl Ether||8,000|
|Resorcinol Diglycidyl Ether||3,000|
|Allyl Glycidyl Ether||2,000|
|Octyl-Decyl Glycidyl Ether||200|
|Isopropyl Glycidyl Ether||100|
|Triglycidyl Glycerol Ether||70|
*A worker may be exposed to more than one glycidyl ether, thus the exposure estimates are not additive. Due to the difficulty of obtaining data regarding the composition of trade name products, these estimates may be low. [return to table]
**Exposures were entered into the NOHS data base either under the specific glycidyl ether (when the information was available) or under the general term “glycidyl ethers” (when more specific information was not available). To the extent that an exposure to a specific glycidyl ether was reported as exposure to “glycidyl ethers,” the data may underestimate occupational exposure to individual glycidyl ethers.[return to table]
Table 2. Industries Where the Majority of Occupational Exposures to Glycidyl Ethers Occur*
|Transportation Equipment||Stone, Clay, and Glass Products|
|Instruments and Related Products||Medical and Other Health Services|
|Chemicals and Allied Products||Fabricated Metal Products|
|Electrical Equipment and Supplies||Building Materials and Farm Equipment|
|Special Trade Contractors||Food and Kindred Products|
|Automotive Dealers and Service Stations||Rubber and Plastic Products|
|Transportation by Air||Furniture and Fixtures|
|Miscellaneous Repair Services||Amusement and Recreation Services|
|Machinery, except electrical||Leather and Leather Products|
The National Occupational Hazard Survey, conducted between 1972 and 1974, was based on a sample of businesses selected by the Bureau of Labor Statistics and consisted of approximately 5,000 establishments employing nearly 900,000 workers in 67 standard metropolitan areas throughout the United States. This sample was representative of non-agricultural businesses covered under the Occupational Safety and Health Act of 1970.
NIOSH is not aware of any studies investigating the possible occurrence of testicular atrophy or hemopoietic abnormalities in humans exposed to glycidyl ethers. However, other effects observed in humans include dermatitis, irritation and allergic reactions. The NIOSH glycidyl ethers criteria document1 provides detailed evaluative review of reported adverse effects resulting from exposure to glycidyl ethers.
Laboratory Animals — Testicular Atrophy and Hemopoietic Abnormalities
Studies in several different research laboratories indicate that some of the glycidyl ethers are capable of producing adverse effects to the testes and hemopoietic system in various species of laboratory animals. Reported testicular abnormalities (including testicular atrophy with decreased spermatogenic activity) following exposure to glycidyl ethers are presented in Table 3. Table 4 summarizes reported hemopoietic abnormalities following exposure to glycidyl ethers, including alteration of the leukocyte count, atrophy of lymphoid tissue, and bone marrow cytotoxicity. These abnormalities were usually observed along with pneumonia and/or toxemia, and therefore may be secondary effects. However, especially in light of the generalized reduction in leukocytes and the atrophy of lymphoid tissues, the observed hemopoietic abnormalities may have been predisposing factors to pneumonia. While none of the individual research reports are conclusive with respect to the ability of glycidyl ethers to produce permanent changes to the testes or hemopoietic system in laboratory animals, the pattern of effects displayed in Tables 3 and 4 is reason for concern.
The NIOSH glycidyl ethers criteria document1 contains an evaluative review of the literature on effects of exposure to glycidyl ethers. Reported adverse effects in laboratory animals include sensitization, and skin and eye irritation, as well as mutagenic and tumorigenic activity.
Table 3. Reported Testicular Disorders Following Exposure to Glycidyl Ethers
|Agent (reference)||Animal||Exposure||Reported Testicular Disorder|
|Allyl Glycidyl Ether3||Rat||400 mg/kg intramuscular injections on days 1,2,8, and 9
animals sacrificed on day 12
|focal necrosis of the testis in 1 of 2 of the 3 surviving rats|
|n-Butyl Glycidyl Ether4||Rat||38 ppm, 75 ppm, 150 ppm, 300 ppm by inhalation, seven hours/day, five days/week for a total of 50 exposures||atrophic testes in 5 of 10 at 300 ppm; very small testes in 1 of 10 at 300 ppm; slight patchy atrophy of the testes in 1 of 10 animals at 75 ppm|
|Diglycidyl Ether5||Rat||125 mg/kg, 250 mg/kg cutaneous daily application, 5 days/week, total of six applications||focal necrosis of the testes|
|3 ppm by inhalation 4 hours/day, 5 days/week total of 19 exposures||necrosis of the tubules of the testes in 1 of 15 animals|
|0.3 ppm by inhalation, 4 hours/day, 5 days/week total of 60 exposures||poorly defined focal degeneration of the germinal epithelium in 5 of 10 animals|
|Rabbit||single 24 hour inhalation exposure of 24 ppm||greatly atrophied testes in two animals which died on the evening of the fifth day|
|Phenyl Glycidyl Ehter6||Rat||1.75 ppm, 5.84 ppm, 11.20 ppm by inhalation 6 hours/day for 19 consecutive days||Initial Report: focal degenerative changes involving the seminiferous tubules in both gonads in 1 of 8 at 1.75 ppm, 1 of 8 at 5.84 ppm, and 3 of 8 at 11.20 ppm|
|Supplemental Examination: 1 of 8 in each of 1.75, 5.84, and 11.20 ppm groups had a marked degree of gonad change|
|Triethylene Glycol Diglycidyl Ether7||Mouse||7208 mg/kg total dose administered in 12 intraperitoneal injection, 3 per week for four weeks, animals sacrificed 39 weeks after the first injection||testular atrophy with decreased spermatogenic activity|
Table 4. Reported Hemopoietic Abnormalities in Animals Following Exposure to Glycidyl Ethers
|Allyl Glycidyl Ether3||Rat||400 mg/kg intramuscular injections on days 1,2,8, and 9
animals sacrificed on day 12
|atrophy or loss of lymphoid tissue in 2 of 3 rats decreased leukocyte count|
|n-Butyl Glycidyl Ether3||Rat||400 mg/kg intramuscular injections for 3 consecutive days||increased leukocyte count|
|Butanediol Diglycidyl Ether8||Rat||100 mg/kg, 200 mg/kg single intraperitoneal injection||bone marrow cytotoxicity|
|Diethylene Glycol Diglycidyl Ether8||Rat||100 mg/kg, 200 mg/kg, 400 mg/kg single intraperitoneal injection||bone marrow cytotoxicity|
|Diglycidyl Ether5||Rat||single application of 0.5 g/kg, 1 g/kg to shaved backs||decreased leukocyte count|
|daily skin application of 125 mg/kg, 5 days/week for 4 weeks; skin application on days 1,2,3,4,5, and 8 of 250 mg/kg, 500 mg/kg||decreased leukocyte count increase in percentage of polymorphonuclear cells|
|fewer nucleated cells of the bone marrow|
|enlarged myeloid cells in 250 and 500 mg/kg groups.|
|lymphoid atrophy of the thymus at 500 mg/kg.|
|3 ppm by inhalation, 4 hours/day, 5 days/week, total of 19 exposures||decreased leukocyte count|
|Rat||Single application of 1.13 g/kg to shaved back||decreased leukocyte count|
|Single intravenous injection of 50 mg/kg, 100 mg/kg, 200 mg/kg||decreased leukocyte count|
|23 nucleated erythrocytes per 100 leukocytes in 100 mg/kg group|
|Dog||25 mg/kg intravenous injection, 2 injections, six days apart, in two dogs
3 weekly injections in one dog
|decreased leukocyte count|
|Phenyl Glycidyl Ether3||Rat||400 mg/kg intramuscular injections for 3 consecutive days||increased leukocyte count|
Reports from different laboratories present a pattern of findings indicating that some of the glycidyl ethers may be capable of producing testicular atrophy and hemopoietic abnormalities in various species of laboratory animals. While none of the individual research reports are conclusive with respect to the ability of glycidyl ethers to produce permanent changes to the testes or hemopoietic system in laboratory animals, some of the changes observed may act as predisposing factors to systemic problems. NIOSH is not aware of any studies investigating the possible occurrence of testicular atrophy or hemopoietic abnormalities in humans exposed to glycidyl ethers. The possibility of these effects occurring in humans is reason for concern. Therefore, the occupational health community is advised of the possibility of these effects appearing in workers exposed to glycidyl ethers.
The “NIOSH Criteria for a Recommended Standard……Occupational Exposure to Glycidyl Ethers” was transmitted to the Occupational Safety and Health Administration (OSHA), Department of Labor, on June 30, 1978.1 This criteria document contains detailed recommendations regarding maximum exposure levels medical surveillance, labeling and posting, personal protective clothing an equipment, informing employees of hazards, work practices, sanitation, monitoring and recordkeeping requirements as well as sampling and analytical procedures. Existing occupational exposure limits for specific glycidyl ethers are listed in Table 5.
Table 5. Existing Occupational Exposure Limits for Specific Glycidyl Ethers
|Allyl Glycidyl Ether||10 ppm (45 mg/cum)*||45 mg/cu m (9.6 ppm)|
|n-Butyl Glycidyl Ether||50 ppm (270 mg/cu m)**||30 mg/ cu m (5.6 ppm)|
|Diglycidyl Ether||0.5 ppm (2.8 mg/cu m)*||1 mg/cu m (0.2 ppm)|
|Isopropyl Glycidyl Ether||50 pp (240 mg/cu m)**||240 mg/cu m (50 ppm)|
|Phenyl Glycidyl Ether||10 ppm (60 mg/cu m)**||5 mg/cu m (1 ppm)|
**8-hour time-weighted average
NIOSH advises strict adherence to this detailed recommended occupational standard for glycidyl ethers described in the NIOSH criteria document. Particular attention should be given to appropriate medical surveillance in order to detect testicular atrophy or hemopoietic abnormalities in exposed workers.
NIOSH requests that any information regarding testicular atrophy or hemopoietic abnormalities in workers exposed to glycidyl ethers be reported to the NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies, Industry-Wide Studies Branch, Medical Section, Telephone: (513) 684-3593.
J. Michael Lane, M.D.
- NIOSH Criteria for a Recommended Standard …. Occupational Exposure to Glycidyl Ethers. United States Department of Health, Education, and Welfare. Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Cincinnati (1978), in press.
- Standard Industrial Classification Manual 1967. Executive Office of the President, Bureau of the Budget, Washington (1967).
- Kodama, J. K., R. J. Guzman, M. K. Dunlap, G. S. Loquvam, R. Lima and C. H. Hine: Some Effects of Epoxy Compounds on the Blood. Arch. Environ. Health 2: 56-67 1961.
- Anderson, H. H., C. H. Hine, R. J. Guzman and J. S. Wellington: Chronic Vapor Toxicity of n-Butyl Glycidyl Ether. Confidential Report to Shell Development Company, Emeryville, California from Department of Pharmacology and Experimental Therapeutics, University of California School of Medicine, San Francisco, U. C. Report No. 270, February 4, 1957.
- Hine, C. H., J. K. Kodama, R. J. Guzman, M. K. Dunlap, K. Lima and G. S. Loquvwam: Effects of Diglycidyl Ether on Blood of Animals. Arch. Environ. Health 2: 37-50 1961.
- Terrill, J. B. and H. J. Trochimowicz: A Two-Generation Reproduction and Mutagenic Study in Rats. E. I. du Pont de Nemours and Company, Haskel Laboratory for Toxicology and Industrial Medicine, Haskell Laboratory Report No. 163-75, Wilmington, Delaware, April 7, 1975.
- Shimkin, M. B., J, H. Weisburger, E. K. Weisburger, N. Gubareff and Suntzeff: Bioassay of 29 Alkylating Chemicals by the Pulmonary-Tumo Response in Strain A Mice. J. Nat. Cancer Inst. 36: 915-935 (1966).
- Hendry, J. A., R. F. Homer, F. L. Rose and A. L. Walpole: Cytotoxic Agents: II, Bis-Epoxides and Related Compounds. Brit. J. Pharmacol. 6: 235-255
- Occupational Safety and Health General Industry Standards. United State Department of Labor, Occupational Safety and Health Administration, OSHA Publication 2206, Washington (1976). (29 CFR 1910.1000)
Identifiers and Synonyms for Allyl Glycidyl Ether
Chemical Abstracts Service Registry Number 106-92-3
NIOSH RTECS Number RRO875000
Chemical Formula C6H10O2
|AGE||Ether, Allyl 2,3-epoxypropyl|
|Allyl 2,3-Epoxypropyl Ether||Glycidyl Allyl Ether|
|Allyl Glycidyl Ether||Oxirane, [(2-Propenyloxy)methyl]-|
Identifiers and Synonyms for n-Butyl Glycidyl Ether
Chemical Abstracts Service Registry Number 2426-08-6
NIOSH RTECS Number TX4200000
Chemical Formula C7H14O2
|1-Butoxy-2, 3-epoxypropane||Ether, Butyl 2,3-Epoxypropyl|
|3-Butoxy-1, 2-epoxypropane||Ether, Butyl Glycidyl|
|Butyl Glycidyl Ether||Glycidyl Butyl Ether|
|n-Butyl Glycidyl Ether||Oxirane, (Butoxymethyl)-|
|2,3-Epoxypropyl Butyl Ether||Propane, 1-Butoxy-2,3-epoxy-|
Identifiers and Synonyms for Diglycidyl Ether
Chemical Abstracts Service Registry Number 2238-07-5
NIOSH RTECS Number KN2350000
Chemical Formula C6H10O3
|Bis(2,3-Epoxypropyl) Ether||Ether, Diglycidyl|
|Di(2,3-epoxy)propyl Ether||NSC 54739|
|Diglycidyl Ether||Oxirane, 2,2′-[Oxybis(methylene)]bis-|
Identifiers and Synonyms for Diglycidyl Ether of Bisphenol A
Chemical Abstracts Service Registry Number 1675-54-3
NIOSH RTECS Number TX3800000
Chemical Formula C21H24O4
|4,4′-B is (2,3-epoxypropoxy) diphenyldimethylmethane|
|Bis(4-hydroxyphenyl)dimethylmethane Diglycidyl Ether|
|2,2-Bis(p-hydroxyphenyl)propane Diglycidyl Ether|
|2,2-Bis(4-hydroxyphenyl)propane Diglycidyl Ether|
|Bisphenol A Diglycidyl Ether|
|Dian Diglycidyl Ether|
|Diglycidyl Bisphenol A|
|Diglycidyl Bisphenol A Ether|
|Diglycidyl Diphenylolpropane Ether|
|Diglycidyl Ether of 2,2-Bis(p-hydroxyphenyl)propane|
|Diglycidyl Ether of 2,2-Bis(4-hydroxyphenyl)propane|
|Diglycidyl Ether of Bisphenol A|
|Diglycidyl Ether of 4,4′-Isopropylidenediphenol|
|4,4′-Dihydroxydiphenyldimethylmethane Diglycidyl Ether|
|p,p‘-Dihydroxydiphenyldimethylmethane Diglycidyl Ether|
|Diomethane Diglycidyl Ether|
|4,4′-Isopropylidenediphenol Diglycidyl Ether|
|Oxirane, 2,2′ [(1-Methylethylidene)bis(4,1-phenyleneoxymethylene)]bis-|
|Propane, 2-2-Bis [(p-(2,3-epoxpropoxy)phenyl]-|
Identifiers and Synonyms for Isopropyl Glycidyl Ether
Chemical Abstracts Service Registry Number 4016-14-2
NIOSH RTECS Number TZ3500000
Chemical Formula C6H12O2
|1,2-Epoxy-3-isopropoxypropane||Isopropyl Glycidyl Ether|
|Glycidyl Isopropyl Ether||[(1-Methylethoxy)methyl] oxirane|
Identifiers and Synonyms for Phenyl Glycidyl Ether
Chemical Abstracts Service Registry Number 122-60-1
NIOSH RTECS Number TZ3675000
Chemical Formula C9H10O2
|Benzene, (2,3-Epoxypropoxy)-||3-Phenoxy-1,2-propylene Oxide|
|2,3-Epoxypropyl Phenyl Ether||Phenoxypropene Oxide|
|2,3-Epoxypropylphenyl Ether||Phenoxypropylene Oxide|
|Ether, 2,3-Epoxypropyl Phenyl||y-Phenoxypropylene Oxide|
|Glycidol Phenyl Ether||Phenyl 2,3-Epoxypropyl Ether|
|Glycidyl Phenyl Ether||Phenyl Glycidyl Ether|
|Oxirane, (Phenoxymethyl)-||Phenylglycidyl Ether|
|Phenol Glycidyl Ether||Propane, 1,2-Epoxy-3-phenoxy|
Identifiers and Synonyms for Resorcinol Diglycidyl Ether
Chemical Abstracts Service Registry Number 101-90-6
NIOSH RTECS Number VH1050000
Chemical Formula C12H14 04
Araldite ERE 1359
Diglycidyl Resorcinol Ether
NCI – C54966
Oxirane, 2,2′- [1,3-Phenylenebis(oxymethylene)]bis-
Resorcinol Bis(2,3-epoxypropyl) Ether
Resorcinol Diglycidyl Ether
Resorcinol Glycidyl Ether
Resorcinyl Diglycidyl Ether
Chemical Structures of Some Glycidyl Ethers
|allyl glycidyl ether|
|n-butyl glycidyl ether|
|diglycidyl ether of bisphenol A|
|isopropyl glycidyl ether|
|phenyl glycidyl ether|
|resorcinol diglycidyl ether|