6-Propyl-2-thiouracil

SECTION 2: Hazards identification

CHEMWATCH HAZARD RATINGS Min Max Min/Nil=0 Flammability 1 Low=1 Toxicity 2 Moderate=2 High=3 Body Contact 0 Extreme=4 Reactivity 1 Chronic 2 CANADIAN WHMIS SYMBOLS EMERGENCY OVERVIEW RISK Harmful if swallowed. Danger of cumulative effects. Limited evidence of a carcinogenic effect.

Potential Acute Health Effects

SWALLOWED ■ Accidental ingestion of the material may be harmful; animal experiments indicate that ingestion of less than 150 gram may be fatal or may produce serious damage to the health of the individual. ■ Side effects from the usage of antithyroid agents include nausea, vomiting, distress, headache, skin rashes, hives, and itching. Other effects include fever, joint pain, lupus, inflammation of blood vessels, liver inflammation, and hair loss. 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. SKIN ■ Skin contact is not thought to produce harmful health effects (as classified using animal models). Systemic harm, however, has been identified following exposure of animals by at least one other route and the material may still produce health damage following entry through wounds, lesions or abrasions. ■ 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 either adverse health effects or irritation of the respiratory tract following inhalation (as classified using animal models). Nevertheless, adverse effects have been produced following exposure of animals by at least one other route and 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.

Potential chronic health

■ There has been concern that this material can cause cancer or mutations, but there is not enough data to make an assessment. Repeated or long-term occupational exposure is likely to produce cumulative health effects involving organs or biochemical systems. 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. Prolonged exposure to high doses of thyroid inhibitors cause severe enlargement of the thyroid and reduced levels of circulating thyroid hormone. Overexposure affects taste and smell and may cause fever and liver damage. Oral administration produced thyroid tumours in mice, rats, hamsters and guinea pigs; pituitary adenomas were seen in mice.