Cadmium

What is Cadmium?

Cadmium is a chemical element with the symbol Cd and atomic number 48. It is found naturally in the earth’s crust, where it commonly exists in combinations with other elements. For example, cadmium oxide (a mixture of cadmium and oxygen), cadmium chloride (a combination of cadmium and chlorine), and cadmium sulphide (a mixture of cadmium and sulphur) are commonly found in the environment. 

Cadmium is a lustrous, silver-white, ductile, very malleable metal. Its surface has a bluish tinge and the metal is soft enough to be cut with a knife, but will tarnish in the air. 

It is soluble in acids but not in alkalis. Cadmium doesn’t have a distinct taste or smell.

What is Cadmium used for?

Cadmium has many uses in a range of industries. Until the 1990’s, it was used as a pigment in dyes and leather tanning agents due to its ability to produce yellow, orange and red hues. 

Other common uses for cadmium today are in batteries, solar cells, alloys, electroplating coatings, plastic stabilisers, solder alloys, paint/plastic production, parasite treatment in farm animals and pigments. Most of the world’s cadmium is used in the production of rechargeable nickel cadmium (Ni-Cd) batteries.

China, South Korea, and Japan are the leading producers of cadmium in the world, with North America following.

Most of the world's cadmium is found in Ni-Cd batteries.
Most of the world’s cadmium is used in producing Ni-Cd batteries.

Cadmium Hazards

The routes of exposure for cadmium include; inhalation, ingestion and skin and eye contact. 

Inhalation of cadmium may produce severely toxic effects, possibly fatal. People with already compromised respiratory function (conditions such as emphysema or chronic bronchitis), may suffer further disability upon inhalation. Inhalation of freshly formed metal oxide particles may result in “metal fume fever” Symptoms of this may be delayed for up to 12 hours and may include; sudden thirst, a metallic or foul taste in the mouth, upper respiratory tract irritation and a cough. 

Ingestion of cadmium may be seriously damaging to the health of the individual, with animal experiments indicating that ingestion of several hundred milligrams, likely to prove fatal. Ingesting cadmium salts causes a person to vomit soon after and the chemical is not retained, making this route of exposure less harmful than inhalation. Symptoms of ingestion include; excessive salivation, nausea, persistent vomiting, diarrhoea and stomach pain.

Skin contact to the chemical is not thought to produce harmful health effects, however, open wounds or cuts can lead to the chemical entering the bloodstream which may produce more harmful health effects as a result. 

According to animal experiments, it is expected to produce severe ocular lesions which can remain for 24 hours or more after the exposure. 

There is evidence that cadmium causes prostate and kidney cancer in humans and has been shown to cause lung and testicular cancer in animals. The United States Department of Health and Human Services determined that cadmium and certain cadmium compounds are probable or suspected carcinogens, but there is little evidence that it causes cancer at the low levels typically occurring in the environment. Inhalation of cadmium can cause lung cancer, however ingestion of the chemical is not thought to cause cancer.

Cadmium Safety

If inhaled, remove the patient from the contaminated area to the nearest fresh air source and monitor their breathing. Lay them down and keep them warm and rested. If the patient is not breathing and you are qualified to do so, perform CPR. Seek medical attention without delay. 

If swallowed, a dose of at least 3 tablespoons of activated charcoal in water should be taken. Vomiting may be recommended but is generally avoided due to the risk of aspiration, however if charcoal is unavailable, inducing vomiting is the answer. Seek medical attention without delay.

If skin exposure occurs, remove all contaminated clothing, footwear and accessories and cleanse the affected area with plenty of soap and water. Contaminated clothing should be washed prior to wearing again. In the case of burn, immediately apply cold water to burn by immersion or wrapping with a clean saturated cloth. Treat for shock by keeping the person warm and in a lying position. Seek medical attention if symptoms persist. 

If the chemical is exposed to the eyes, flush the eyes out immediately with fresh running water for at least 15 minutes, remembering to wash under the eyelids. Removal of contact lenses should only be done by a skilled individual. Seek medical attention without delay.

Cadmium Safety Handling

Emergency eyewash fountains should be accessible in the immediate area of the potential exposure to the chemical and there should always be adequate ventilation (install local exhaust if necessary).

The PPE recommended when handling cadmium includes; safety glasses with side shields, chemical goggles, dust respirators, protective gloves, overalls and boots.

Cadmium is a classified carcinogen and must be handled with the proper care.
Cadmium is a classified carcinogen and must be handled with the proper care.