The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the data available for absorption through the skin for arsenic [7440‐38‐2] and its inorganic compounds including gallium arsenide [1303‐00‐0]. Available publications are described in detail.
Dermal penetration has been demonstrated for pentavalent arsenic compounds, and it can also be assumed for trivalent arsenic compounds. The extent of skin penetration depends on the solubility of the substance. Arsenic and its inorganic compounds are classified in Category 1 for Carcinogenic Substances and in Category 3 A for Germ Cell Mutagens. No MAK value (maximum concentration at the workplace) could be established. No safe concentration range can therefore be estimated, so that an increased carcinogenic or genotoxic risk should be assumed even for low amounts absorbed percutaneously. Therefore, inorganic arsenic compounds, with the exception of arsenic itself and gallium arsenide, which are both very poorly soluble in water, are designated with an “H” (for substances that can be absorbed through the skin in toxicologically relevant amounts).