Recent Regulatory Actions Concerning Hexavalent Chromium-Containing Leather Products
Hexavalent chromium [Cr(VI)] is commonly used as a tanning agent during the production of leather for various clothing articles (NTP, 2018). The levels of residual Cr(VI) in chromium-tanned leathers are influenced by the tanning process itself as well as several aging factors, including storage conditions, temperature, humidity, and UV light (Fontaine et al, 2019) The most common health effect associated with Cr(VI) exposure is the elicitation of an allergic contact dermatitis (ACD) response in previously sensitized individuals. In both Europe and the United States, there has been a recent and substantial increase in regulatory actions related to the Cr(VI) content of leather clothing products.
In 2015, the European Chemicals Agency (ECHA) restricted the Cr(VI) content in leather clothing products to 3 mg/kg based on a recommendation from the Committee for Risk Assessment (RAC) (REACH, 2014). The RAC conducted a theoretical risk assessment based on assumptions regarding ACD elicitation thresholds and migration rates of Cr(VI) from leather onto skin and derived a lowest observed adverse exposure level (LOAEL) of 0.02 µg/cm2 (ECHA, 2012). Because the LOAEL was below the detection limit of 3 mg/kg, the acceptable Cr(VI) concentration in clothing was set at the detection limit of 3 mg/kg. Audits conducted by Sweden’s Chemicals Agency in 2019, indicated that all but one of 70 leather products including gloves, watch straps, cellphone cases, and other skin-contact leather items, contained Cr(VI) concentrations that exceeded 3 mg/kg (Bloomberg Environment, 2019). Similarly, in Denmark, 35% of 43 tested leather products, including baby shoes and watch straps, contained levels of Cr(VI) greater than 3 mg/kg (Hansen et al, 2002).
While there is no federal regulation in the United States for Cr(VI) in leather products, California’s Proposition 65 has regulated Cr(VI) on the basis of carcinogenicity and reproductive toxicity since 1987 (OEHHA - Prop65). Proposition 65 is a right-to-know act that is intended to protect citizens in consumer, occupational, and community exposure settings. Over the last year, there has been a substantial increase in the number of Proposition 65 notices issued for Cr(VI) compounds in leather goods (SGS, 2019; Attorney General of California). For example, from 2015 to 2018, a total of 12 notices were issued for Cr(VI)-containing materials such as recycled tires, game calls, cement, emissions, and drinking water; none of the notices were related to leather clothing. Conversely, in 2019 alone, 39 notices were issued for Cr(VI)-containing substances, [JB1]25 of which were issued for leather goods such as gloves and footwear. In 2020 thus far, 4 notices have been issued for Cr(VI)-containing articles, all of which were leather gloves. The Prop 65 notices for leather goods have been based on dermal exposure or the recommended use of the product (generally skin contact); they also indicate that hand to mouth oral contact is a possible route of exposure.
When evaluating compliance with the regulations that govern Cr(VI) levels in leather clothing and other consumer products, it is important to understand not only the Cr(VI) content of the products, but also the basis of the applicable regulatory statute and the potential exposures to and toxicological effects of Cr(VI). Cardno ChemRisk has experience in evaluating potential health risks from a wide range of consumer products and exposure scenarios, including Cr(VI) in leather goods. We provide recommendations for screening level testing and assistance, exposure and toxicological assessments, and comparative risk calculations. For more information regarding Cardno ChemRisk’s consumer products testing and assessment capabilities, please contact Dr. Ernest Fung or Dr. Brent Finley.