OSHA Hazard Information Bulletins
March 15, 1990
| MEMORANDUM FOR: | REGIONAL ADMINISTRATORS |
| |
| THRU: | LEO CAREY
Director
Office of Field Programs |
| |
| FROM: | THOMAS J. SHEPICH
Director
Directorate of Technical Support |
| |
| SUBJECT: | Health Hazard Information Bulletin:
N-Nitroso Compounds in Industry |
The Directorate of Technical Support issues Hazard Information Bulletin
(HIB) in accordance with OSHA Instruction CPL 2.65 to provide relevant
information regarding unrecognized or misunderstood health hazards,
inadequacies of materials, devices, techniques, and engineering controls.
HIBs are initiated based on information provided by the field staff, studies,
and reports and concerns expressed by safety and health professionals,
employers, and the public. Information is compiled based on a thorough
evaluation of available facts, literature and in coordination with
appropriate parties. HIBs do not necessarily reflect OSHA policy.
The purpose of this bulletin is to alert field personnel of the potential
for amine compounds, used in many industrial processes, to be nitrosated with
nitrogen oxides from the air. This bulletin was initiated by the United
Rubber, Cork, Linoleum and Plastic Workers of America (URW) who indicated to
OSHA their concern about a number of amine compounds that are used in rubber
or as rubber additives.
According to the National Institute for Occupational Safety and Health
(NIOSH) these amine compounds are considered animal carcinogens. The
International Agency for Research on Cancer (IARC) has classified nitrosated
amine compounds as Group 2A or Group 2B and the National Toxicology Program
(NTP) has designated them as anticipated human carcinogens. Other health
effects include effects on the liver, kidney, lungs, bladder, esophagus, skin
and eyes. Also, individual substances such as N-Nitrosaminethylamine can
produce other symptoms and can include headache, fever, weakness, stomach
upsets, enlargement of the liver and jaundice.
Under a contract sponsored by the National Institute for Occupational Safety
and Health (NIOSH), a total of 55 on-site plant surveys were conducted in 40
separate United States manufacturing facilities. N-Nitroso compounds were
found in 25 of the 40 plants surveyed. The industries where N-Nitroso
compounds were found, include the dye industry, rubber industry, fish meal
factory, leather industry, manufacturing and users of synthetic metalworking
fluids, foundries, and the soap, detergent and surfactant industry. Both the
rubber and leather industries were found to have relatively high levels of
nitrosamines.
RUBBER INDUSTRY
The NIOSH survey of eight plants manufacturing rubber and related products
indicated that seven of the facilities were contaminated with one or more of
the following compounds:
1- N-Nitrosodiethylamine (NDEA)
2- N-Nitrosodimethylamine (NDMA)
3- N-Nitrosomorpholine (NMOR)
4- N-Nitrosodiphenylamine (NDPhA)
5- N-Nitrosopyrrolidine (NPYR)
NIOSH states that exposures to N-Nitroso compounds occur in many operations
in the rubber industry including, Mill Operator, Banbury Operator, Tray
Compounder, Extruder Operator, Cure Heater Operator, Mold Press Operator,
Press Operator, Laminator, Calendar Operator and others.
NIOSH sampled in a number of rubber plants and found personal exposure
levels that range from:
0.1 ug/m(3) to 16.0 ug/m(3) NDMA, NDEA, NDBA, NMOR; Geauga Company
0.08 ug/m(3) to 1.8 ug/m(3) NDMA; B.F. Goodrich Company
1.2 ug/m(3) to 3.1 ug/m(3) NMOR; B.F. Goodrich Company
.005 ug/m(3) to .160 ug/m(3) NDEA, DMNA, NMOR, NDPhA; Uniroyal, Inc.
0.11 ug/m(3) to 1.6 ug/m(3) N-Nitrosodiisopropylamine (NDiPA), NDMA,
NDPhA, NMOR; Kelly Springfield Tire Co.
0.05 ug/m(3) to 0.98 ug/m(3) NDMA, NMOR; ST. Clair Rubber Company
In one rubber plant survey, NIOSH reported that levels were below detectable
limits for nitrosamine or metabolite biological samples in blood, urine and
stool. However, according to NIOSH, the negative findings in the biological
samples may reflect the fact that they were collected only during the last
two visits of a four visit survey, during which time the airborne nitrosamine
levels had been greatly reduced.
TANNING INDUSTRY
NDMA was the primary nitrosamine found associated with the tanning industry
with the highest levels being found in those tanneries which used
dimethylamine sulfate in the hide unhairing process. Because none of the
process water samples or other bulk samples were found to contain significant
amounts of any N-Nitroso compounds, NIOSH concluded that worker exposure will
occur via inhalation. NIOSH also concluded that the source for the airborne
NDMA in these tanneries is due to nitrosation of dimethylamine, in either the
gas phase or on surfaces, by airborne oxides of nitrogen.
NIOSH conducted process area/operation air sampling and obtained bulk
samples in a number of tanneries and leather plants for N-Nitroso compounds
and found:
0.3 ug/m(3) to 10.8 ug/m(3) NDMA; A.F. Gallun & Son Corp.
0.7 ug/m(3) to 3.3 ug/m(3) NDMA; Blue Side Tannery.
0.05 ug/m(3) NDMA and 0.12 ug/m(3) - 0.25 ug/m(3) NMOR; Prime Tannery.
OTHER INDUSTRIES
In the fish processing industry a small amount (10 ppt to 20 ppt (parts per
trillion)) of NDMA was found in air and bulk samples. This may be the result
of naturally occurring dimethylamine reacting with either nitrite or
atmospheric nitrogen oxides.
During the manufacturing of dyes, nitrite and amines are frequently used and
depending upon the dye being manufactured and the type of operation,
N-Nitroso compounds may be produced as unwanted by-products. Worker exposure
to known N-Nitroso compounds via inhalation in the azo dye industry did not
appear to be a serious problem at three plants NIOSH visited. However, not
all dye manufacturing processes involving all of the reaction conditions and
raw material combinations have been examined by NIOSH.
In the soap, detergent and surfactant industry, the only N-Nitroso compound
NIOSH found, in its three plant survey, was NDMA (highest level was 0.8
ug/m(3). Airborne dimethylamine, used in the synthesis of some cationic
surfactants, may have, according to NIOSH, formed NDMA with ambient levels of
nitrogen oxides.
Only one of the five iron and steel casting plants that NIOSH surveyed was
found to be contaminated with N-Nitroso compounds. NDMA and NDEA were found
within this plant. An amine catalyzed sand core process was in operation at
the time of the survey and triethylamine was reported being used. According
to NIOSH, this amine, and dimethylamine from an unknown source, may have
reacted with the nitrogen oxides being generated by the many combustion
sources within the foundry to produce the discovered N-Nitroso compounds.
According to NIOSH, N-Nitrosodiethanolamine (NDE1A) is a known contaminant
in metalworking fluids formulated with nitrite and ethanolamines. Therefore,
those plants that use these products may have workers exposed to pre-formed
NDE1A. Under certain conditions, such as heat, NDE1A can be formed from the
precursors present in metalworking fluids.
Currently there are no OSHA Permissible Exposure Limits (PELs) for these
amine compounds. OSHA does regulate N-Nitrosodimethylamine under 29 CFR
1910.1016. Use of the OSHA General Duty Clause, 5(a)(1) of the OSHA Act may
be considered for other amine compounds. Refer to the OSHA Field Operations
Manual (FOM) Chapter IV, A.2.a. for guidance.
At present, OSHA uses Thermosorb/N media or a 15 ml isopropanol bubbler for
air sampling and these samples are analyzed by using the Thermal Energy
Analyzer (TEA) or High Pressure Liquid Chromatography for most N-Nitroso
compounds. OSHA's Salt Lake City Analytical Laboratory (SLCAL) stated that
in general there are no problems except for N-Nitrosophenylamine which is
unstable in isopropanol used in the bubbler. Bubbler samples must be
protected for light during and after sampling. Samples must be either stored
in a freezer or analyzed within six days after collection. The limit of
detection for most nitrosamines is as low as .02 ug per 75 liter of collected
sample, according to the OSHA SLCAL.
OSHA Compliance Officers should be aware of the hazards of N-Nitrosoamine
compounds to avoid potential exposures to themselves. Protective clothing,
should include gloves, gowns, masks, and goggles, especially in laboratory
settings, for the protection of the face, skin, eyes and other parts of the
body.
Appropriate compliance action, based on available information, should be
taken to ensure that proper engineering controls, work practices, protective
clothing and respirators are being utilized. Engineering controls should
include process enclosure, local exhaust ventilation and dilution or general
ventilation. Isolation of the operation or equipment should also be
considered.
OSHA's standard for N-Nitrosodimethylamine requires, as a minimum, that
employees be provided with a half-face, filter-type respirator (NIOSH/MSHA
approved) for dusts, mists, and fumes, in accordance with 29 CFR 1910.134.
Compliance Officers should exercise professional judgement, based on expected
exposure and the most current literature findings, in selecting respiratory
protection for personal use or in any compliance action for other nitrosamine
compounds.
Please disseminate this bulletin to all Area Offices, State Plan States and
Consultation Project Officers.
BIBLIOGRAPHY
Fine, D.H. 1980. Exposure Assessment to Preformed Environmental
N-Nitroso Compounds from the Point of View of our own Studies. Oncology. 37:
99-202.
Fajen, J.M., et al. 1979. N-Nitrosamines in the Rubber and Tire
Industry. Science. 205: 1262-1264.
IARC. International Agency for Research on Cancer. N-Nitroso
Compounds: Occurrence, Biological Effects and Relevance to Human Cancer in
Proceedings of the VIIIth International Symposium, I.K. O'Neill, Editor, IARC
Scientific Publication No. 57, pp. 937-942, 1984.
NIOSH, Health Hazard Evaluation Report #HHE 79-126-951, U.S. HHS,
CDC, NIOSH; St. Clair Rubber Company, Marysville, Michigan.
NIOSH, Health Hazard Evaluation Report #HETA 79-109-1538, U.S. HHS,
CDC, NIOSH; Kelly-Springfield Tire Company, Cumberland, Maryland.
NIOSH, Health Hazard Evaluation Report # TA 80-121-919, U.S. HHS,
CDC, NIOSH; Kelly-Springfield Tire Company, Freeport, Illinois.
NIOSH, Health Hazard Evaluation Report # HETA 8l-O45B-l2l6, U.S.
HHS, CDC, NIOSH; Uniroyal, Incorporated, Mishawaka, Indiana.
NIOSH, Health Hazard Evaluation Report # HETA 85-003-1834, U.S. HHS,
CDC, NIOSH; B.F. Goodrich, Woodburn, Indiana.
NIOSH, Health Hazard Evaluation Report # HETA 81-107-1331, U.S. HHS,
CDC, NIOSH; Geauga Company, Middlefield, Ohio.
NIOSH, Industry Wide Study IWS-lO6-l2. In-depth Industrial Hygiene
Report of the A.F. Gallum and Son Corporation, Milwaukee, WI. July 22-24,
1980.
NIOSH, Industry Wide Study. Industrial Hygiene Report Survey for
N-Nitroso Compounds at Blue Side Tannery, St. Joseph, MO, January 16,
1979.
NIOSH, Survey for N-Nitroso Compounds at Prime Tannery, Berwick, ME,
February 5, 1979.
NIOSH, Industry Wide Report IWS-72.32, U.S. HHS, NIOSH; Survey for
N-Nitroso Compounds at Oaks Tire Plant, B.F. Goodrich Company, Oaks, Pa.,
January 23, 1979.
NIOSH Pocket Guide to Hazardous Chemical Hazards, #85-114, 1986.
U.S. HHS, NIOSH
NIOSH Technical Report # 83-114, U.S. HHS, CDC NIOSH; N-Nitroso
Compounds in the Factory Environment, June 1983.
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