CPCS Specialist Guideline

BROMATES/CHLORATES

I. Mechanism of Toxicity

· Background: Bromates are found in home kits for hair permanent neutralizers. Commercially, bromates are used in bakeries, and as a component in fusing explosives. Bromates had previously been used in matchheads. Chlorate salts are compounds found in matchheads, fireworks, commercial herbicides, and in dye production. Chlorates were also once used in antiseptic mouthwashes.

· Bromates and chlorates are strong oxidizing agents. Both may cause hemolysis and methemoglobinemia. In animal studies, bromates are estimated to be 20-30 times more toxic than chlorates. Bromates react with gastric hydrochloric acid to release hydrobromic acid. Bromates also cause sensorineural damage that may result in irreversible deafness. This effect is attributed to bromate’s oxidizing action and ability to penetrate membranes.

II. Toxic Dose

· Potassium bromate: In children, ingestion of 2-4 ounces of 2% potassium bromate has resulted in severe poisoning. The estimated lethal dose of potassium bromate ranges from 200-500 mg/kg.

· Potassium chlorate: In children, 20 or more wooden matches (330 mg) or more than 2 matchbooks of paper matches (220 mg) containing potassium chlorate may be toxic. The lethal dose in adults ranges from 7.5-35 grams.

III. Clinical Presentation

· Within minutes to hours of toxic ingestions of either compound, abdominal pain, nausea, vomiting and hematemesis develop. The patient may also develop lethargy, convulsions, and coma.

· Hemolysis and methemoglobinemia are more profound with chlorates, but can also occur in exposures to bromates.

· Acute tubular necrosis and renal failure may occur in exposures to either bromates or chlorates, resulting from both direct effects and hemolysis.

· Deafness may occur with bromates.

IV. Diagnosis

· The presence of hemolysis, methemoglobinemia, renal failure, and hearing loss should suggest bromates.

· Although serum bromide levels may be available at certain institutions, they may not correlate with the severity of bromate poisoning. Serum bromate and chlorate levels are not routinely measured and are not clinically useful in cases of poisoning.

Recommended laboratory tests:

· Methemoglogin levels and CBC (to look for hemolysis).

· Renal function tests

V. Treatment

Decontamination

· Activated charcoal is probably not effective

· For bromate ingestions, alkalinizing the stomach may prevent the pH-dependent conversion of bromate to hydrobromic acid. Administration of antacids can be attempted.

Specific drugs and antidotes

· Sodium thiosulfate may inactivate bromate/chlorate ions. To use, administer 10% sodium thiosulfate, 10-50 ml (0.2-1 ml/kg) intravenously. Although there is no clinical data proving efficacy, no significant risk is associated with the doses recommended and early intravenous administration may be beneficial.

· Methylene blue 1-2 mg/kg (0.1-0.2 ml/kg of 1% sol) IV slowly over 5 minutes for methemoglobinemia. May repeat dose in 30-60 minutes.

Enhanced elimination

· The kidney eliminates bromates and chlorates. Hemodialysis may be indicated for large ingestions or in patients with renal failure.

Consider referral to HCF if:

·     Patient is significantly symptomatic.

·     Patients with suspected intentional self-harm ingestions.

·     Children ingesting > 1 g or 1-2 oz of 2% bromate solution.

·     Children ingesting > 20 wooden matches or > 2 books of paper matches.

Mode of transport:

Private auto:

· Accidental exposure, and patient is asymptomatic or mildly symptomatic. A second adult should accompany the victim and the driver to assist the victim if necessary.

Consider paramedic transport:

· Patient has significant altered mentation.

· Prolonged (greater than 1 hour) transport time.

· Self harm exposure.

When to Consider Backup Consultation

· Patients with severe hemolysis or refractory hypotension, or those who may need dialysis.

· Patients with hearing loss.

VI. Follow-up calls

Home-managed cases:

· Follow up in 4-6 hours post exposure at SPI discretion to identify any symptoms.

HCF managed cases:

· Once every 8 hours while symptomatic in the ED or ICU.

· Once daily until medically cleared.

· Minimal recommended information to obtain at follow up:

1.     Brief clinical status: e.g., awake, oriented, vital signs

2.     Methemoglobin levels

3.     Renal function, CBC, and other labs if available

Approved 12/98

Revised: October 2005