Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MALEIC HYDRAZIDE

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-H4-N2-O2, "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", "3, 6-pyridazinediol",
"3, 6-pyridazinediol", "pyridazine-3, 6-diol", "pyridazine-3, 6-diol", "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", Burtolin, Chemform, De-cut, De-sprout,
"Drexel-Super P", "Fair 30, PS", KMH, MAH, "Maintain 3", Malazide, Malzid, "MH 30, 40,
36 Bayer", "Regulox , W", Retard, "Royal MH-30, Slo-Gro", "Sprout Off, Stop", Stuntman,
Sucker-stuff, "Super Desprout", Vonalhyde, Vondrax, "pesticide/ herbicide/ plant growth
regulator"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Although ingestion is not thought to produce harmful effects, the material may still be damaging to the health of the individual following ingestion, especially where pre-  existing organ (e.g. liver, kidney) damage is evident. Present definitions of harmful or toxic substances are generally based on doses producing mortality (death) rather than those producing morbidity (disease, ill-health). Gastrointestinal tract discomfort may produce nausea and vomiting. In an occupational setting however, ingestion of insignificant quantities is not thought to be cause for concern.  

EYE

  Although the material is not thought to be an irritant, direct contact with the eye may cause transient discomfort characterized by tearing or conjunctival redness (as with windburn). Slight abrasive damage may also result. The material may produce foreign body irritation in certain individuals.  

SKIN

  The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  Open cuts, abraded or irritated skin should not be exposed to this material.  Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.  

INHALED

  The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting.  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

  There has been some concern that this material can cause cancer or mutations but there is not enough data to make an assessment.  Long term exposure to high dust concentrations may cause changes in lung function i.e. pneumoconiosis; caused by particles less than 0.5 micron penetrating and remaining in the lung. Prime symptom is breathlessness; lung shadows show on X-ray.  When 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.