EH40/2005 Workplace exposure limits

The HSE have issued a new report containing the list of workplace exposure limits for use with the Control of Substances Hazardous to Health Regulations (as amended). This latest version of EH40 has been updated to include new and revised workplace exposure limits (WELS) introduced by the 2nd and 3rd Indicative Occupational Exposure Limit Values (IOELV) Directives. It will guide those responsible for controlling exposure to hazardous substances at work.

This 2011 edition replaces the previous version, first published in 2005 and takes account of new substances and limits introduced in 2007 and 2011.

New and revised workplace exposure limits (WELs) in force from 1 October 2007 In 2007 the European Commission's second Directive on Indicative Occupational Exposure Limit Values (2006/15/EC) was implemented in Great Britain and Northern Ireland.

The details can be summarised as follows:

There were new entries for the following substances:

• 2-(2-Butoxyethoxy) ethanol
• Isopentane
• Methyl acrylate
• 2-(2-Methoxyethoxy) ethanol
• Neopentane
• Pentane
• Pyrethrum (purified of sensitising lactones)
• Vinyl acetate.

New 8-hour time-weighted averages (TWA) were introduced for:

• Diphosphorus pentoxide
• Phosphine.

A new short-term exposure limit (STEL) was introduced for:

• Phosphorus pentachloride.

The following substance was removed:

• Pyrethrins (ISO).

The WELs (either 8-hour TWA or STEL or both) for the following substances were amended:

• Aminoethanol
• Bromine
• Chlorine
• Cyanamide
• Diethylamine
• Diphosphorus pentasulphide
• Morpholine
• Nitric acid
• Nitrobenzene
• Phosphine
• Toluene.

The 8-hour TWA for the following substances were withdrawn:

• Chlorine
• Nitric acid.

The short-term exposure limit (STEL) for the following substance was withdrawn:

• Nitrobenzene.

A 'Skin' notation was added for the following substances:

• 2-Aminoethanol
• Cyanamide
• 2-(2-Methoxyethoxy).

New and revised workplace exposure limits (WELs) in force from December 2011 On 18 December 2011, the European Commission's third Directive on Indicative Occupational Exposure Limit Values (2009/161/EU)1 was implemented in Great Britain and Northern Ireland.

This Directive requires Member States of the European Union to introduce domestic occupational exposure limits for the substances listed in the Annex to the Directive. Additionally, the level of the domestic limit must take account of the Indicative Occupational Exposure Limit Value (IOELV).

The Health and Safety Executive has approved new and revised workplace exposure limits (WELs) required to implement the third IOELV Directive.

Details of the changes that came into force on 18 December 2011 can be summarised as follows:

There were new entries for the following substances:

• Bisphenol A
• Mercury and divalent inorganic mercury compounds including mercuric oxide and mercuric chloride (measured as mercury)
• Methyl acrylate
• Sulphuric acid (mist)
• Vinyl acetate.

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

• Bisphenol A
• Mercury and divalent inorganic mercury compounds including mercuric oxide and mercuric chloride (measured as mercury)
• Sulphuric acid (mist).

New 8-hour time-weighted average (TWA) and short-term exposure limits (STELs) are required for the following substances:

• Methyl acrylate
• Vinyl acetate.

The following substances require reductions to the existing workplace exposure limits (WELs):

• Carbon
• Disulphide
• N,N-Dimethylformamide
• 1,4-Dioxane
• 2-Ethoxyethanol
• 2-Ethoxyethyl acetate
• Ethyl acrylate (STEL only)
• 2-Methoxyethanol
• 2-Methoxyethyl acetate
• n-Methyl-2-pyrrolidone.

The STEL for 1,4-dioxane is removed.

The WEL is increased for:

• Tertiary-butyl-methyl-ether.

A STEL is introduced for:

• Phenol.

The existing 8-hour time-weighted average WEL is removed and the existing STEL is reduced for:

• Methyl isocyanate.

The Chemicals (Hazard Information and Packaging for supply) Regulations will gradually be replaced by the European Regulation on Classification, Labelling and Packaging of Substances and Mixtures - known as the CLP Regulation. The CLP Regulation provides a transitional period to allow a gradual migration from the existing system to the new regime. The transitional period ran to 1 December 2010 for substances, and continues until 1 June 2015 for mixtures (preparations).

The transitional period will end on 1 June 2015 when the CLP Regulation enters fully into force.

HSE
Dec 2011