CAREX Canada

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CAS No. 79-46-9

Image: Wikimedia Commons

IARC Monograph Vol. 71, 1999 (Group 2B)

General Information

2-Nitropropane is a colourless oily liquid with a mild, sweet odour.^[2,3] It is flammable and soluble in water.^[2] It may also be referred to as dimethylnitromethane or isonitropropane.^[3] There are numerous other synonyms and product names; see HSDB for more information.^[4]

2-Nitropropane was classified by IARC as a group 2B carcinogen, possibly carcinogenic to humans, based on animal studies linking exposure to liver cancer in rats.^[1] The carcinogenicity of 2-nitropropane in humans was not evaluated due to the lack of adequate epidemiological data.^[1]

Chronic inhalation exposure to 2-nitropropane in occupational settings is associated with non-cancer health effects such as nausea, vomiting, diarrhea, severe headaches, and pulmonary irritation.^[5] Acute exposure to high concentrations of 2-nitropropane can cause liver damage and death.^[5,6]

2-Nitropropane has been ranked by CAREX Canada as Group B (possible immediate high priority) for occupational settings and as Group C (further investigation needed) for environmental settings. Prioritization was based on the carcinogenicity and other toxic properties of the substance, the prevalence of exposure in Canada, and the feasibility of assessing exposure.

Regulations and Guidelines

Occupational Exposure Limits (OEL)

Canadian Jurisdictions	OEL (ppm)
Canada Labour Code	10
MB, NL, PE, NB, NS, AB, QC	10
BC	5
SK, ON	10 20 [stel]
NT, NU	25 [c]
YT	25
Other Jurisdictions	OEL (ppm)
ACGIH 2010 TLV	10

ppm = parts per million

stel = short term exposure limit (15 min. maximum)

c = ceiling (not to be exceeded at any time)

TLV = Threshold Limit Value (8 hour maximum)

Canadian Environmental Guidelines

Jurisdiction	Designation	Year
Food Additives Permitted for Use	CE	2006^[7]

CE = permitted as carriers or extraction solvents

2-Nitropropane was not included in other Canadian environmental guidelines reviewed.^[8-10]

Canadian Agencies/Organizations

Agency	Designation/Position	Year
Health Canada	DSL – high priority substance with intermediate potential for exposure	2006^[11]
Challenge to Industry	Batch 8	2010^[12]

2-Nitropropane was not included in Environment Canada's Toxic Substance List (CEPA Schedule 1).^[13]

Main Uses

2-Nitropropane is primarily used as a solvent in inks, paints, varnishes, coatings, adhesives and various organic compound resins.^[1,2] 2-Nitropropane may also act as a chemical intermediate in the production of different propane derivatives such as 2-nitro-2-methyl-1-propanol and 2-amino-2-methyl-1-propanol.^[2,3] It is used to a lesser extent as a component in paint and varnish removers;^[6] a chemical intermediate in the manufacturing of pharmaceuticals, dyes, insecticides, and textile chemicals;^[5,6] and an additive in explosives, propellants and fuels for internal combustion.^[2]

Canadian Production and Trade

2-Nitropropane is not manufactured in reportable quantities in Canada.^[6] No quantitative Canadian commercial production and trade information was found for 2-nitropropane.^[14,15]

Occupational Exposures

Inhalation is the most important route of occupational exposure to 2-nitropropane, although dermal and ingestive exposures are also possible.^[2,3] The main occupations exposed include workers involved in 2-nitropropane manufacturing and handling, paint, ink, pigment coating and varnish production, printing and painting, industrial construction and maintenance, shipbuilding and maintenance, furniture manufacturing, tire manufacturing, food packaging and scientific research.^[2,3]

Since the production of 2-nitropropane is often an enclosed process, exposure is limited.^[3] The highest exposures occur during the handling, transport and use of 2-nitropropane and 2-nitropropane-containing products.^[3]

CAREX Canada is reviewing whether it is feasible to prepare exposure estimates for Canadian workers exposed to 2-nitropropane. This will likely depend on availability of exposure data.

Environmental Exposures

Environmental exposure to 2-nitropropane is estimated to be very low in Canada.^[3,6] Sources of potential environmental exposure include contaminated ambient air and water near industrial sites of 2-nitropropane manufacture and use, and cigarette smoke.^[1]

2-Nitropropane may be present in trace amounts in certain pharmaceuticals which use 2-nitropropane as a chemical intermediate during production.^[6] Approximately 1.1-1.2 µg of 2-nitropropane is present in the mainstream smoke of a single unfiltered cigarette.^[6]

Exposure may also occur through the consumption of foods processed with solvents containing 2-nitropropane or packaged with materials containing 2-nitropropane, such as beverage can coatings and packaging inks.^[3,6] Recent food packaging submissions to Health Canada's Food Directorate suggest that the latter use is unlikely in Canada.^[6] The use of 2-nitropropane as a carrier and extraction solvent in vegetable oil is permitted in Canada. It is no longer used in North America for this purpose, however.^[6,7] Although the use of 2-nitropropane in food processing is not recommended by the WHO, Canadians may be exposed through the consumption of imported foods processed with 2-nitropropane.^[3,6]

Use of 2-nitropropane in consumer products has largely been eliminated. Adhesives, paints and coatings containing 2-nitropropane are mostly used in industrial and commercial applications.^[6] 2-Nitropropane release into the environment is reportable to the NPRI in Canada. No releases have been reported since 1996, when 0.125 tonnes were released by 1 company involved in plastics and foam manufacture.^[6,17]

2-Nitropropane was not included in the Household Products Database.^[18]

Sources

Published March 2011

2-Nitropropane