Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MALEIC HYDRAZIDE, POTASSIUM SALT

NFPA

PRODUCT USE

Systemic herbicide, treatment of tobacco plants, post- harvest sprouting inhibitor, weed
control, sugar content stabiliser in beets, synthesis of pyridazine. Plant growth
regulator of grass growth on lawns, roadside verges, embankments and amenity areas and of
growth of shrubs and trees. Inhibits sprouting in potatoes, onions, beets, swedes and
carrots in storage. Prevents sucker development in tobacco and induces dormancy in citrus
fruit. Inhibits cell division in the meristematic region but not cell extension.

SYNONYMS

C4-H3-K-N2-O2, "potassium maleic hydrazidemonopotassium salt of", "3, 6-
dihydroxypyridazine", "3, 6-dihydroxypyridazine", "3, 6-pyridazinedione, 1, 2-dihydro-",
"3, 6-pyridazinedione, 1, 2-dihydro-", "1, 2-dihydropyridazine-3, 6-dione", "1, 2-
dihydropyridazine-3, 6-dione", "1, 2-dihydro-3, 6-pyradizinedione", "1, 2-dihydro-3, 6-
pyradizinedione", "1, 2-dihydro-3, 6-pyridizinedione", "1, 2-dihydro-3, 6-
pyridizinedione", 6-hydroxy-3(2H)-pyridazinone, 6-hydroxy-3(2H)-pyridazinone, "maleic
acid hydrazide", "maleic hydrazine", "N, N-maleoylhydrazine", "N, N-maleoylhydrazine", "1,
2, 3, 6-tetrahydro-3, 6-dioxopyridazine", "1, 2, 3, 6-tetrahydro-3, 6-dioxopyridazine",
"pesticide/ herbicide/ plant growth regulator"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

May cause CANCER.
May cause SENSITIZATION by skin contact.
Toxic by inhalation, in contact with skin and if swallowed.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 40 gram may be fatal or may produce serious damage to the health of the individual.  Ingestion may result in nausea, abdominal irritation, pain and vomiting.  Considered an unlikely route of entry in commercial/industrial environments.  

EYE

  Although the material is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).  

SKIN

  Skin contact with the material may produce toxic effects; systemic effectsmay result following absorption.  The material is not thought to be a skin irritant (as classified using animal models). Temporary discomfort, however, may result from prolonged dermal exposures. Good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  The material may cause skin irritation after prolonged or repeated exposure and may produce on contact skin redness, swelling, the production of vesicles, scaling and thickening of the skin.  

INHALED

  The material is not thought to produce respiratory irritation (as classified using animal models). Nevertheless inhalation of the material, especially for prolonged periods, may produce respiratory discomfort and occasionally, distress.  Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.  

CHRONIC HEALTH EFFECTS

  Skin contact with the material is more likely to cause a sensitization reaction in some persons compared to the general population.  There is ample evidence that this material can be regarded as being able to cause cancer in humans based on experiments and other information.  

  Principal routes of exposure are by accidental skin and eye contact andinhalation of generated dusts.  When maleic hydrazide was injected into infant mice (55 mg in the first  3 weeks of life) there was a high incidence of remote tumours and  hepatomas. It seems unlikely that maleic hydrazide presents a high  carcinogenic hazard. The complete absence of pulmonary carcinomas and  multiple adenomas makes it improbable that the carcinogenicity of maleic  hydrazide is caused by a presumptive ring scission in vivo to yield  hydrazine or to trace contamination with this compound which is a potent  lung carcinogen in several species of rats and mice, although also  hepatocarcinogenic in CBA mice.