Cadmium fumes, toxicity

Inhalation exposure to high levels of cadmium fumes or dust is intensely irritating to respiratory tissue. Particle size appears to be a more important determinant of toxicity than... 

Some toxic chemicals cause both local and systemic effects. For example, cadmium fumes, which may occur in industrial environments, can cause lung damage when inhaled, but the cadmium absorbed will damage the kidneys. 

Dimethylcadmium, (CH3)2Cd, is an oily liquid at room temperature and has a very unpleasant odor. The compound melts at -4.5"C and boils at 106°C. It decomposes in contact with water. Diethyl-cadmium is likewise an oil it melts at -21°C, boils at 64°C, and reacts explosively with oxygen in air. Dipropylcadmium, (C3H7)2Cd, is an oil that melts at -83°C, boils at 84°C, and reacts with water. The dialkyl cadmium compounds are distillable, but decompose above about 150°C, evolving toxic cadmium fume. 

Chronic cadmium toxicity occurs in industrial workers exposed to cadmium fumes. The symptoms are those of nephrotoxicity, bone disease and. to a lesser extent, hepatotoxicity. Renal stone formation may be increased. 

Cadmium was previously used for batteries, electroplating, pigments, and alloys. However, applications of cadmium have declined over the years because of its toxicity to humans. Acute exposure to cadmium fumes can cause flu-Uke symptoms (examples chills, fever, etc.). 

Precautions have to be taken during the dissolution of cadmium precipitates or the galvanic precipitation of cadmium with 2inc to remove possible mist and toxic gases such as arsine. Suitable exhaust hoods and scmbbers must be provided. The fume that may be formed during cathode melting must be removed similarly. 

Emissions from other nonferrous metal facilities are primarily metal fumes or metal oxides of extremely small diameter. Zinc oxide fumes vary from 0.03 to 0.3 jiim and are toxic. Lead and lead oxide fumes are extremely toxic and have been extensively studied. Arsenic, cadmium, bismuth, and other trace metals can be emitted from many metallurgical processes. 

Fire Hazards - Flash Point Not flammable Flammable Umits in Air (%) Not flammable Fire Extinguishing Agents Not pertinent Fire Extinguishing Agems Not To Be Used Not pertinent Special Hazards cf Combustion Products Toxic hydrogen fluoride and cadmium oxide fumes can form Behavior in Fire Not pertinent Ignition Temperature Not pertinent Electrical Hazard Not pertinent Burning Rate Not pertinent. 

Cadmium powder, dust, and fumes are all flammable and toxic if inhaled or ingested. Cadmium and many of its compounds are carcinogenic. 

Caution. Cadmium(II) compounds are extremely toxic, and care should be used when handling them. The reactions should be carried out in a well-ventilated fume hood, and gloves should be worn at all times. 

Acute poisoning may result from inhalation of cadmium dusts and fumes (usually cadmium oxide) and from the ingestion of cadmium salts. The major toxic effects are due to local irritation. In the case of oral intake, these include nausea, vomiting, salivation, diarrhoea and abdominal cramp. Cadmium is more toxic when inhaled. Signs and symptoms, which appear after a few hours, include irritation of the upper respiratory tract, chest pains, nausea, dizziness and diarrhoea. Permanent lung damage may occur in the form of emphysema and peribronchial and perivascular fibrosis. Death is usually due to massive pulmonary oedema. 

General caution and safety. The metal alkyls trimethylaluminum, trimethylgallium, trimethylindium, triethylindium, dimethylzinc, and diethyl-zinc all spontaneously inflame in air (pyrophoric) and are violently reactive toward water and carbon dioxide. Dimethylcadmium fumes upon exposure to air but does not inflame, and decomposes, sluggishly, in water. As with cadmium dichloride, and in common with all cadmium compounds, dimethylcadmium is extremely toxic. A dry powder extinguisher, sand bucket, and fire blanket should be at hand at all times. 

Wear nitrile rubber gloves, laboratory coat, and eye protection. Avoid breathing dust. Cadmium compounds are not so toxic as to present serious disposal problems. The insoluble compounds can be mixed with wet sand, swept up, and treated as normal waste. The soluble salts can be mopped up with water, and a 10% aqueous solution of sodium metasilicate (Na2Si03-5H20) added until no further precipitation occurs. Adjust the pH to 11.0 with 2 M sulfuric acid. The solid is collected by filtration or by allowing the filtrate to evaporate in the fume hood. It is dried, packaged, and labeled for disposal in a secure landfill.14... 

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