New edition of EH40 on workplace exposure limits published
Published: 10 Sep 2018

A new edition of EH40 on workplace exposure limits has been published.

This latest edition has been updated to include new and revised workplace exposure limits (WELs) introduced by Directive 2017/164/EU, establishing a fourth list of indicative occupational exposure limit values.

It also reintroduces the biological monitoring guidance values for chlorobenzene, isocyanates and 4,4-methylenedianiline which were omitted from the previous edition.

New and revised WELs

The new and revised WELs set out in Directive 2017/164/EU had to be implemented into UK law by 21 August 2018.

There are new entries for:

  • 2-ethylhexan-1-ol;
  • Acetic acid;
  • Acrylic acid;
  • Amitrole;
  • But-2-yne-1,4-diol;
  • Diacetyl;
  • Glycerol trinitrate;
  • Methyl formate;
  • Nitroethane;
  • Nitrogen dioxide;
  • Nitrogen monoxide;
  • Sulphur dioxide;
  • Hydrogenated terphenyl;
  • Tetraethyl orthosilicate.

New 8-hour time-weighted averages (TWAs) are introduced for:

  • 2-ethylhexan-1-ol;
  • Amitrole;
  • But-2yne-1,4-diol;
  • Calcium dihydroxide (respirable fraction);
  • Calcium oxide (respirable fraction);
  • Hydrogen cyanide (as cyanide);
  • Nitrogen monoxide;
  • Tetraethyl orthosilicate.

New 8-hour TWA and short-term exposure limits (STELs) are introduced for:

  • Acetic acid;
  • Acrylic acid;
  • Diacetyl;
  • Glycerol trinitrate;
  • Methyl formate;
  • Nitrogen dioxide;
  • Sulphur dioxide;
  • Hydrogenated terphenyl.

New skin notations have been added for:

  • 1,4-dichlorobenzene;
  • Glycerol trinitrate;
  • Methyl formate;
  • Tetrachloroethylene.

The following substances required reductions to the existing WELs:

  • 1,4-Dichlorobenzene;
  • Acrolein;
  • Bisphenol A;
  • Carbon monoxide;
  • Carbon tetrachloride;
  • Manganese and inorganic manganese compounds;
  • Methylene chloride (dichloromethane);
  • Potassium cyanide (as cyanide);
  • Sodium cyanide;
  • Tetrachloroethylene;
  • Vinylidene chloride.

A STEL was introduced for:

  • Acetic acid;
  • Acrylic acid;
  • Calcium dihydroxide;
  • Calcium oxide;
  • Carbon tetrachloride;
  • Diacetyl;
  • Diphenyl ether;
  • Glycerol trinitrate;
  • Lithium hydride;
  • Manganese and inorganic manganese compounds;
  • Methyl formate;
  • Nitroethane;
  • Nitrogen dioxide;
  • Potassium cyanide (as cyanide);
  • Sodium cyanide (as cyanide);
  • Sulphur dioxide;
  • Hydrogenated terphenyl;
  • Vinylidene chloride.

Finally, the existing 8-hour TWA WEL was removed and a STEL adopted for:

  • Lithium hydride.

For more information, see: