Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

ZINC BROMATE

NFPA

PRODUCT USE

Reagent. Intermediate

SYNONYMS

Br2-O6.Zn, "bromic acid, zinc salt"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Contact with combustible material may cause fire.
Irritating to eyes.
Limited evidence of a carcinogenic effect.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Accidental ingestion of the material may be damaging to the health of the individual.  Soluble zinc salts produces irritation and corrosion of the alimentary tract with pain, and vomiting. Death can occur due to insufficiency of food intake due to severe narrowing of the esophagus and pylorus.  Bromate poisoning almost always causes nausea and vomiting, usually with pain of the upper abdomen. Loss of hearing can occur, and bromates damage the kidneys. It can also depress the central nervous system, causing restlessness, apathy and lethargy.  

EYE

  This material can cause eye irritation and damage in some persons.  

SKIN

  Skin contact with the material may damage the health of the individual; systemic effects may result following absorption.  There is some evidence to suggest that this material can cause inflammation of the skin on contact in some persons.  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

  There is some evidence to suggest that the material can cause respiratory irritation in some persons. The body's response to such irritation can cause further lung damage.  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.  Welding or flame cutting of metals with zinc or zinc dust coatings may result in inhalation of zinc oxide fume; high concentrations of zinc oxide fume may result in "metal fume fever"; also known as "brass chills", an industrial disease of short duration. [I.L.O] Symptoms include malaise, fever, weakness, nausea and may appear quickly if operations occur in enclosed or poorly ventilated areas.  

CHRONIC HEALTH EFFECTS

  There has been concern that this material can cause cancer or mutations, but there is not enough data to make an assessment.  Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems.  There is some evidence that human exposure to the material may result in developmental toxicity. This evidence is based on animal studies where effects have been observed in the absence of marked maternal toxicity, or at around the same dose levels as other toxic effects but which are not secondary non-specific consequences of the other toxic effects.  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.  Chronic intoxication with ionic bromides, historically, has resulted from medical use of bromides but not from environmental or occupational exposure; depression, hallucinosis, and schizophreniform psychosis can be seen in the absence of other signs of intoxication. Bromides may also induce sedation, irritability, agitation, delirium, memory loss, confusion, disorientation, forgetfulness (aphasias), dysarthria, weakness, fatigue, vertigo, stupor, coma, decreased appetite, nausea and vomiting, diarrhoea, hallucinations,  an acne like rash on the face, legs and trunk, known as bronchoderma (seen in 25-30% of case involving bromide ion), and a profuse discharge from the nostrils (coryza). Ataxia and generalised hyperreflexia have also been observed. Correlation of neurologic symptoms with blood levels of bromide is inexact. The use of substances such as brompheniramine, as antihistamines, largely reflect current day usage of bromides; ionic bromides have been largely withdrawn from therapeutic use due to their toxicity. Several cases of foetal abnormalities have been described in mothers who took large doses of bromides during pregnancy.  Bromate produces tumours at multiple sites in male rats, including the kidney (adenomas and carcinomas), the thyroid gland (follicular cell adenomas and carcinomas) and the peritoneum (mesotheliomas); In the female rat, only kidney tumours are observed  Further, a clear dose-response relationship exists in tumour incidence and the severity/progression of tumours. The weight of evidence from the rat bioassays clearly indicates that bromate has the potential to be a human carcinogen.  Bromate is mutagenic both in vitro and in vivo. IARC (1986, 1999) has classified  potassium bromate in Group 2B (possibly carcinogenic to humans), concluding that  there is inadequate evidence of carcinogenicity in humans but sufficient evidence of  carcinogenicity in experimental animals. US EPA (2001b) has classified bromate as a  probable human carcinogen by the oral route of exposure under the 1986 EPA Guidelines for Carcinogen Risk Assessment (US EPA, 1986) on the basis of adequate evidence of carcinogenicity in male and female rats. Under the 1999 EPA draft Guidelines for Carcinogen Risk Assessment (US EPA, 1999), bromate is likely to be a human carcinogen by the oral route; the data on the carcinogenicity of bromate via the inhalation route are inadequate for an assessment of its human carcinogenic potential. Health Canada (1999) has classified bromate as probably carcinogenic to humans (sufficient evidence in animals;  no data in humans).  Observation of tumours at a relatively early time and the positive response of bromate in a variety of genotoxicity assays suggest that the predominant mode of action at low doses is due to DNA reactivity. Although there is limited evidence to suggest that the DNA reactivity in kidney tumours may have a non-linear dose-response relationship, there is no evidence to suggest that this same dose-response relationship operates in the development of mesotheliomas or thyroid tumours. Oxidative stress may play a role in the formation of kidney tumours, but the evidence is insufficient to establish lipid peroxidation and free radical production as key events responsible for induction of kidney tumours. Also, there are no data currently available to suggest that any single mechanism, including oxidative stress, is responsible for the production of thyroid and peritoneal tumours by bromate.  Bromate was mutagenic in Salmonella typhimurium strain TA100 in the presence of  S9 activation and produced chromosomal aberrations in cultured Chinese hamster  fibroblast cells. In assays using V79 Chinese hamster ovary cells, bromate increased the frequency of cells with micronuclei, the number of chromosomal aberrations and the number of DNA strand breaks and induced gene mutations at the HPRT locus. Positive results were also observed in in vivo studies. The number of aberrant metaphase cells was increased following single oral doses of potassium bromate in Long-Evans rats . Following either intraperitoneal injection or gavage dosing, the number of micronuclei was elevated in mouse micronucleus tests with MS/Ae and CD-1 mice strains. Intraperitoneal injection of bromate in F344 rats significantly increased the number of micronuclei in reticulocytes. Evidence of DNA damage, as indicated by elevated levels of 8-hydroxy-deoxyguanosine, has been observed in rats orally administered potassium bromate. The weight of evidence  demonstrates that bromate is clearly mutagenic in in vitro assays. The positive findings in in vivo studies show that this mutagenicity is also expressed in vivo. Thus, bromate should be considered a mutagenic disinfection by-product.  Welding or flame cutting of metals with zinc or zinc dust coatings may result in inhalation of zinc oxide fume; high concentrations of zinc oxide fume may result in "metal fume fever"; also known as "brass chills", an industrial disease of short duration. [I.L.O] Symptoms include malaise, fever, weakness, nausea and may appear quickly if operations occur in enclosed or poorly ventilated areas.