China’s National Health Commission has updated its occupational exposure limits (OELs) for the country’s Harmful Factors in the Workplace standard for the first time since 2007.

Standard GBZ2 is divided into two parts: Part 1: chemically harmful factors; and Part 2: Physical factors.

This update only covers the first part and was released 29 August. It will become mandatory from 1 April 2020.

The update contains four OEL tables, the first three of which are mandatory. They provide one or more of the following:

• the permissible concentration-time weighted average (PC-TWA);
• the permissible concentration-short term exposure limit (PC-STEL); or
• the maximum allowable concentration (MAC).

OELs for chemical hazards, dust and biological factors in workplace air are all covered.

The update also adds a new column – critical adverse health effect – to table one (chemical hazards) along with the following definition: “The adverse health effects that are used to determine the allowable exposure level of an occupational hazard, ie, the occupational exposure limit.”

The first three tables cover a combined total of 410 substances. This is an increase of 22 on the 2007 version. They include the addition of limits for:

• 1-bromopropane (1-BP); and
• methyl tert-butyl ether (MTBE).

A recent US EPA draft risk evaluation for the solvent 1-BP provisionally determined that the substance may present unreasonable risks to workers, occupational non-users, consumers and bystanders, under certain conditions of use.

In February, Japan’s Ministry of Health, Labour and Welfare (MHLW) included MTBE on a list of seven hazardous substances subject to workplace exposure reporting in 2020 under the country’s Industrial Safety and Health Law (ISHL).

The fourth table in the update is new and contains recommended biological monitoring indicators and biological occupational exposure limits for 28 substances. It covers biological exposure limits such as levels of benzene, mercury, lead and 1-BP in urine.

The updated standard also covers the following:

• improvements to the relevant requirements for monitoring and test methods;
• the addition of sensitisation markers for 16 substances, skin markers for four substances, and carcinogenic markers for 14 substances;
• adjustment of cancer markers for seven substances;
• the addition of nine concepts or definitions related to occupational exposure;
• deletion of terms in five normative references; and
• incorporation of nitric oxide exposure limits into the exposure limits of nitrogen dioxide.

Workplace exposure limits in Asia

Australia is currently seeking comments on draft evaluation reports and recommended workplace exposure standards for 50 chemicals ranging from acetaldehyde to benzoyl chloride.

This is the second of 16 reviews planned for workplace exposure standards for airborne contaminants.

In July, Vietnam’s Health Environment Management Agency (Vihema) published a circular confirming that its updated workplace airborne exposure limits and testing methods for 50 substances will become mandatory from 9 December.

On 1 July, Taiwan’s labour ministry (MoL) implemented a workplace air exposure limit for 1-BP and stricter limits for several other chemicals.

(Source : https://chemicalwatch.com/81871/china-health-commission-releases-updated-occupational-exposure-limits)