Résumé : |
In this two-part paper the first will look of the basics of chromium and how the different types of chromium are tested. In the second part, more detailed chemistry will be covered to allow greater understanding of this complex subject.
Hexavalent chromium, Cr(VI), is not intentionally added to leather during its manufacture. Cr(VI) is formed during poor chromium management (or design) of the process and treatment of the leather articles made of chromium tanned material.
A European Union (EU) Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Annex XV dossier was submitted to the European Chemical Agency (ECHA) on January 19 2012, by Denmark providing evidence that exposure to Cr(VI) through die skin from leather articles posed a risk to human health by inducing an allergic response. Restrictive measures in Europe were requested and die ars Risk Assessment Committee (RAC) and the Committee for Socio-Economic Analysis (SEAC) considered it.
The RAC concluded (on November 28 ,2012) that a content in leather of 3 mg/kg (3 parts per million or 0,0003%, by dry weight) of Cr(VI) is expected to be 80% effective in reducing Cr(VI)-related allergic dermatitis. The SEAC agreed (on March 6, 2013) that an EU-wide restriction was appropriate to address the identified risks relative to the socio-economic balance of an enforcement.
In March 2014 the new restriction was introduced into REACH Annex XVII and from May 2015 leather articles touching the skin should not be placed on die market when they contain Cr(VI) in concentrations equal in excess of 3 parts per million (ppm). The restriction excludes second-hand articles placed on die market before May 1, 2015.
Cr(VI) has been listed on the Californian Safe Drinking Water and Toxic Enforcement Act of 1986 (also known as Proposition 65) since 1988 due to Prop 65's concern over links to cancer, and reproduction/ developmental toxicity. |