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CAS No. 302-01-2

Wikimedia Commons, Hydrazine^[1]

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

General Information

Hydrazine is a clear, colourless liquid.^[3,4] It has a distinctive ammonia-like odour and is highly flammable.^[3] It may also be referred to as diamine or anhydrous hydrazine. There are numerous other synonyms and product names; see HSDB for more information.^[5]

Hydrazine has been classified by IARC as Group 2B, possibly carcinogenic to humans.^[2] Hydrazine is carcinogenic in experimental animals. Exposure caused increased incidence of mammary and lung tumours in mice; lung, liver, and nasal tumours in rats; and liver and thyroid tumours in hamsters. However, there is inadequate epidemiological evidence for carcinogenicity of hydrazine in humans.^[2] Two small cohort studies found men exposed to hydrazine had no elevated risk of cancer.^[2]

Additionally, hydrazine is corrosive and skin contact may cause burns and dermatitis.^[5,13] Inhalation and ingestion cause irritation of the respiratory and digestive systems, respectively.^[4,5] Exposure may also cause central nervous system health effects such as nausea, vomiting, convulsions, tremors, lethargy, seizures, neuritis and, in severe cases, coma.^[4,5,13] Long term exposure to hydrazine may cause liver, kidney, and reproductive organ damage.^[4,5]

Hydrazine has been ranked by CAREX Canada as Group B (possible high priority) for both the occupational and 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	0.01 [sk]
AB, BC, MB, NB, NL, NS, ON, PE	0.01 [sk]
SK	0.01 [sk] 0.03 [stel]
QC	0.1 [sk]
YT	0.1
NT, NU	0.1 [sk] 0.3 [stel]
Other Jurisdictions	OEL (ppm)
ACGIH 2010 TLV	0.01 [sk]

ppm = parts per million

sk = easily absorbed through the skin

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

TLV = Threshold Limit Value (8 hour maximum)

Canadian Environmental Guidelines

Hydrazine is included on Health Canada’s Cosmetics Ingredient Hotlist which means that its use in cosmetics in Canada is prohibited.^[12] Hydrazine was not included in other Canadian government environmental guidelines reviewed.^[10,11,17]

Canadian Agencies/Organizations

Agency	Designation/Position	Year
Health Canada	DSL – high priority substance with intermediate potential for exposure	2006^[6]
CMP Challenge	Batch 10 [Health]	2007^[9]

DSL = Domestic Substances List

CMP = Chemicals Management Plan

Hydrazine was not included in other Canadian government chemical listings reviewed.^[8,9]

Main Uses

Hydrazine is mainly used in the production of agricultural pesticides as a chemical intermediate, in the production of blowing agents used in plastic production and as an anti-corrosion agent in boilers and heating systems.^[3,4]

Hydrazine is also used as a chemical intermediate in spandex production, as a rocket fuel, and a catalyst or reducing agent in a number of chemical processes.^[3,4] It is also used to plate metals on glass, in solders and fluxes, textile dyes, during nuclear fuel processing, as a heat stabilizer, in explosives, and in water treatment and photography developing chemicals.^[3]

Hydrazine was previously used as a medical treatment for cancer and sickle cell disease.^[4]

In Canada, hydrazine is used for the following purposes, as identified under the DSL use codes:^[14]

Antioxidant, corrosion inhibitor, tarnish inhibitor, scavenger, anti-scaling agent
Chemical intermediate
Formulation component
Fragrance, perfume, deodorizer, flavouring agent
Water or waste treatment chemical
Agriculture, other
Biotechnology
Organical chemicals, industrial
Organic chemicals, specialty
Plastics
Plating and surface finishing
Water and waste treatment

Canadian Production and Trade

In 2010, Canada imported hydrazine mainly from France and Korea, and had only had limited export to the US.^[15] Current hydrazine production in Canada, if present, is likely very limited.

Production and Trade

Export
Mainly to the US	5 t of ‘hydrazine and hydroxylamine and their inorganic salts’	2010^[7]
Import
Mainly from France and Korea	517 t of ‘hydrazine and hydroxylamine and their inorganic salts’	2010^[7]

t = tonne

Occupational Exposures

Inhalation and dermal contact are the most important routes of occupational exposure to hydrazine.^[3]

The main occupations exposed include workers involved in production or processing of hydrazine, chemical blowing agents and agricultural chemicals, as well as those who work in water treatment, water boiler system maintenance, and pesticide application.^[2,4]

Other occupational exposure may occur during the military use of hydrazine rocket fuel and in the laboratory where hydrazine is used for research or other experimental purposes.^[4,5,19]

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

Environmental Exposures

The majority of hydrazine found in the environment is generated by industry, although it occurs naturally in small amounts in some plants and algae.^[4]

In Canada, the most significant source of environmental releases of hydrazine is from power generation facility effluents (from using hydrazine as an anti-corrosive agent in boilers).^[19] Emissions and spills or leaks may also occur in industrial plants involved in hydrazine production, processing, and application, or during the use of hydrazine fuels.^[4,19]

Once released, hydrazine is rapidly oxidized and does not persist in the environment,^[4,14,19] therefore public exposures to hydrazine are expected to be low.^[3,19]

Some environmental exposure above ambient levels may occur for individuals living near industrial sites with activities involving hydrazine.^[4]

Hydrazine has also been found in tobacco products and tobacco smoke at a concentration of 32 µg/cigarette.^[3,4] Individuals who chew tobacco, smoke cigarettes or are exposed to second hand smoke are exposed to hydrazine.^[3,4]

No household products are listed with hydrazine as an ingredient in the US Household Products Database.^[16]

A search of an environmental database yielded the following results on current potential for exposure to hydrazine in Canada:

NPRI Database

NPRI 2009^[15]
Search Term:	’hydrazine (and its salts)’
Results:	3 companies

Category	Quantity	Industry
Released into Environment	0.746 t	Nuclear power generation; chemical manufacturing
Disposed of	0.13 t
Sent to off-site recycling	None