Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MAGNESIUM PHOSPHIDE

NFPA

PRODUCT USE

Fumigant. Intermediate

SYNONYMS

Mg3-P2

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

In use, may form flammable/ explosive vapor- air mixture.
Very toxic if swallowed.
Contact with water liberates toxic, extremely flammable gas.
Very toxic to aquatic organisms, may cause long- term adverse effects in the
aquatic environment.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Severely toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 5 gram may be fatal or may produce serious damage to the health of the individual.  At sufficiently high doses the material may be cardiotoxic (i.e. poisonous to the heart).  Symptoms of exposure may be delayed.  At sufficiently high doses the material may be nephrotoxic(i.e. poisonous to the kidney).  At sufficiently high doses the material may be hepatotoxic(i.e. poisonous to the liver).  

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 be a skin irritant (as classified using animal models). Abrasive damage however, may result from prolonged exposures. Good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  Skin contact with the material may damage the health of the individual; systemic effects may result following absorption.  Reactions may not occur on exposure but response may be delayed with symptoms only appearing many hours later.  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

  Inhalation of vapours may cause drowsiness and dizziness. This may be accompanied by narcosis, reduced alertness, loss of reflexes, lack of coordination and vertigo.  Inhalation of dusts, generated by the material during the course of normal handling, may produce severe damage to the health of the individual. Relatively small amounts absorbed from the lungs may prove fatal.  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.  The only signs during exposure to phosphine may be mild respiratory irritation although some victims report dyspnea, weakness, tremor and convulsions.  Phosphine is a very toxic gas. It appears to cause, chiefly, a depression of the central nervous system (CNS) and irritation of the lungs. Inhalation of phosphine causes restlessness, followed by tremors, fatigue, slight drowsiness, nausea, vomiting, cyanosis,  pulmonary oedema, rapid pulse (tachycardia) low blood pressure (hypotension) and frequently, severe gastric pain and diarrhoea. There is often headache, thirst, dizziness,  oppression in the chest and burning substernal pain; later the patient may become dyspneic and develop cough and sputum. Coma or convulsions may precede death.  Overexposure may cause tightness of chest and cough, headache, dizziness, nausea, vomiting, tremor, loss of coordination, diarrhoea. More severe poisoning may result in pulmonary oedema, cardiovascular collapse, cardiac dysrhythmias, myocardial injury, disordered liver function. Mortality from severe poisoning is high. Death has resulted from exposure to 8 ppm phosphine for 1-2 hours per day over several days. Asthma and inflammatory or fibrotic pulmonary disease will be aggravated.  Phosphine which is not eventually expired through the lungs may be metabolised to phosphate, hyposphosphite and phosphite and excreted in urine. Oxyhaemoglobin in mammals is converted by phosphine into a verdichromogen-like material through Fe3+-containg compounds. Birds exposed to phosphine exibited tonic-clonic convulsions; their organs were congested with oxygenated blood on exzmination. Similar effects were seen in cats, rabbits, rats and guinea pigs and death was attributed to respiratory paralysis followed by cardiac arrest.  High concentrations cause inflamed airways and watery swellingof the lungs with edema.  

CHRONIC HEALTH EFFECTS

  Limited evidence suggests that repeated or long-term occupational exposure may 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. Prime symptom is breathlessness; lung shadows show on X-ray.  Chronic phosphine poisoning is said to resemble chronic phosphorus poisonings which produces stomach pains, vomiting and diarrhoea. Chronic poisoning, characterised by anemia, bronchitis, gastrointestinal disturbances and visual, speech and motor disturbances may result from continued exposure to low concentrations.  Chronic exposure may produce systemic poisoning characterised by cachexia (general ill-  health and malnutrition), anaemia, bronchitis, and necrosis of the mandible, the so-  called "phossy" or Lucifer's" jaw. Other bones may also be involved as demonstrated by chronic systemic administration to animals which produces dense growth lines in all extremities proximal to the epiphyses (phosphoschicht).