What is cadmium?
Cadmium is a soft, malleable, bluish-white metal with a low melting point that occurs as a minor component in zinc ores. Therefore, cadmium is produced mainly as a by-product from the refining of zinc ores.
What is cadmium used for?
Cadmium has been used in pigments, corrosion resistant plating on steel and as a stabilizer in plastics. Due to a variety of regulations, cadmium is no longer used in these applications. Three-quarters of cadmium usage today is in nickel-cadmium batteries. It is suspected that manufacturers have started to replace lead, which is highly restricted in children's products, with cadmium. Cadmium is a low cost metal, easy to work with, and has similar characteristics to lead.
Why is cadmium a chemical of concern?
Cadmium is a highly toxic substance, exposure to which can produce a wide range of health effects. Cadmium can replace zinc in the body and can bind strongly to certain biological systems, making it difficult to remove. It can build up in the kidneys and cause kidney damage. It is also been found to cause several types of cancer.
Is cadmium more hazardous in children than adults?
Both adults and children can suffer from the effects of cadmium poisoning. Babies and young children are more susceptible to cadmium poisoning than adults because they often put their hands or other objects in their mouths. Exploring their environment by mouthing objects is a developmental behavior which they outgrow somewhere between 24-36 months. Cadmium can enter the body when they put their hands or other objects in their mouths.
Is cadmium regulated for children's products or jewelry?
Cadmium is not regulated for the total amount found in the metal substrates for children's products or jewelry.
Under the Consumer Product Safety Improvement Act (CPSIA), ASTM F963 has become mandatory. Cadmium is regulated as one of the heavy metals tested under ASTM F963 for coatings on children's toys. Under this requirement, the coatings are tested as soluble or extractable cadmium and not total content.
California regulates cadmium through their Safe Drinking Water and Toxic Enforcement Act of 1986, more popularly referred to as Proposition 65 or Prop 65 (California Health and Safety Code. Section 25249.6, et seq.). Through specific settlements, cadmium is regulated in food and beverage use ceramic and glassware, artist paints and surface coatings on specific consumer products.
Under the REACH requirements, total cadmium is limited in plastics, pigments and paints. Cadmium is also regulated under EN-71 part 3 as extractable cadmium in modeling clay and in paints, coatings, and substrates in toys.
Similar to ASTM F963, Canada regulates cadmium under their Hazardous Substances Act (CHPA) and limits the amount of extractable cadmium in coatings on toys.
What is the difference between total and soluble cadmium?
Total cadmium - this provides the total amount of cadmium in a sample.
Soluble cadmium - this provides the amount of cadmium that can be extracted out of a sample typically using a dilute hydrochloric acid solution similar to stomach acid. ASTM F963, CHPA and EN-71 part 3 define methods for determining the soluble cadmium. Depending on the type of material, the soluble cadmium can be much lower than the total amount of cadmium actually present.
Regulatory activity since the Associated Press study?
Several states, including New York and Mississippi, have proposed laws regulating cadmium in children's jewelry at specific limits. The US House of Representatives has also proposed a bill that would consider any piece of children's jewelry containing cadmium, barium, or antimony as a banned hazardous substance under the Federal Hazardous Substances Act (FHSA). See Bulletin #10B-003 for more information on the Federal proposed bill.
Can XRF be used to test for the presence of cadmium?
As an x-ray received in a hospital goes through the skin and to the bone, similarly, XRF reads both the surface coating and base substrate material.
XRF analysis has some limitations when used for screening: