Glossary / Exposure limits
Skin notation
Skin notation is a label, often shown as "Skin", added to an exposure limit to warn that a chemical can be absorbed through intact skin and contribute significantly to the total dose. It means that air limits alone may not protect a worker who has skin contact.
Explanation
Occupational exposure limits are about what is in the air that is breathed. A chemical with a skin notation can enter the body through the Dermal exposure route as well, and a worker who keeps their air exposure below the limit could still receive a harmful dose through contact with liquid, vapor or contaminated surfaces. For some chemicals, skin absorption can exceed what is inhaled.
The notation is assigned by organizations such as OSHA, NIOSH and ACGIH, using their own criteria, so a chemical may carry a notation from one and not another. It does not describe skin irritation or Corrosive damage, which is a separate matter. It also does not give a numeric limit for skin exposure.
Controlling the hazard means preventing skin contact: suitable Chemical-resistant gloves chosen using Breakthrough time data, protective clothing, good work practices, prompt washing after contact and removal of contaminated clothing. Air monitoring may need to be supplemented with biological monitoring, such as a Biological exposure index (BEI), to show the real total uptake.
Look for the notation in the exposure table on the SDS or in the limits document. If you see it, treat skin protection as a primary control, not an afterthought.
What to do and watch for
- Use gloves proven for the chemical, not general-purpose gloves.
- Wash promptly after any skin contact and change contaminated clothing.
- Consider biological monitoring where skin uptake is significant.
Where it appears on an SDS
- Section 8: Exposure controls / personal protection. The exposure limits table may mark substances with a skin notation and give glove and clothing recommendations.
- Section 11: Toxicological information. Dermal toxicity data show how readily the chemical enters through skin.
SDS content and wording vary by supplier. This page is general reference and does not replace the current SDS for your product.