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Safeguard OSH Solutions - Thomson Reuters

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Safeguard Magazine

Proposed WES updates

RICHARD STEELE explains why some air quality standards are up for review.

Under New Zealand’s performance-based safety and health legislative framework, it is up to individual duty-holders to determine how they meet the requirements of the HSE Act.

Given non-compliance is enforceable, there is considerable pressure on duty-holders to take all practicable steps to identify and manage workplace hazards successfully. Duty-holders therefore have a strong interest in receiving assistance or guidance about how they can effectively manage hazards and avoid breaching the HSE Act.

As a modern regulator the department is committed to influencing practice by providing high quality information in the form of standards, which is a general term to describe the range of guidance material including Regulations, (Approved) codes of practice, guidelines, alerts and bulletins.

Standard-setting framework

The Workplace Services Group of the Department of Labour has recently established a team dedicated to producing standards material within a clearly defined framework, to help those who have duties under the act comply with the legislation.

Standards and guidance sit within a hierarchy, the top end of which is populated by the legislation and regulations. These are mandatory and enforceable. This legislation also provides for the Minister to approve Codes of Practice (or statements, amendments or revocations relating to existing Approved Codes of Practice) on the advice of the Secretary of Labour. Courts may have regard to approved codes of practice (ACOPs) when determining whether someone has failed to comply with the HSE Act. Although ACOPs are non-mandatory, they provide statutory guidance to help meet the minimum requirement for taking “all practicable steps”.

There are also Standards, good practice guides and other guidance and standards material to help duty-holders identify and manage workplace hazards successfully.

The standards team aims to review its standards material at least every five years to ensure it is consistent with international and local best practice and delivers cost effective safety and health outcomes.

Proposed changes to WES

Workplace Exposure Standards (WES) provide a limit on how much or how often typical workers should be exposed to harmful airborne substances in the workplace atmosphere if they are to avoid the risk of adverse health effects.

Now that the transfer of hazardous substances from the former dangerous goods regime to the Hazardous Substances and New Organisms Act 1996 (the HSNO Act) is complete, Workplace Exposure Standards are now enforceable controls under HSNO. They set an enforceable maximum exposure level, while continuing to be a reference point against which to determine if all practicable steps have been taken. (Please note that ERMA has indicated that wood dust is not covered by HSNO legislation.)

All workplaces that use approved hazardous substances must also comply with the HSNO Act as well as the HSE Act. The Department of Labour enforces both laws, and their associated regulations, in workplaces.

The current New Zealand Workplace Exposure Standards, which date from 2002, are being reviewed by the Department of Labour in conjunction with ERMA New Zealand, and with the support of the New Zealand Chemical Industry Council. It is proposed that the WES for certain substances be revised to bring them more into line with current international best practice.

As New Zealand does not have prevalent epidemiological studies of the working population, our standards reflect international experience. Seven substances or groups of substances were prioritised for review, based on significant discrepancies with one or more comparable standards from Australia, USA or the UK.

Table 1: Proposed changes to current Workplace Exposure Standards
SubstanceCurrent WESProposed WES
Benzene5 ppm (8 hour TWA)

0.5 ppm (8 hour TWA)

2.5 ppm (STEL)

Lead (in whole blood)Suspension level of ≥; 3.2 _mol/L, or 3 consecutive monthly estimations of ≥ 2.6 _mol/L

BEI of 1.5 _mol/L

Suspension level of 2.4 _mol/L

Return to work level of 1.93 _mol/L

Formaldehyde1 ppm (Ceiling)

0.3 ppm (8 hour TWA)

0.6 ppm (STEL)

Methyl bromide5 ppm (8 hour TWA)1 ppm (8 hour TWA)
Crystalline silica0.2 mg/m3 for respirable quartz (8 hour TWA)0.1 mg/m3 for respirable quartz
 0.1 mg/m3 for respirable cristobalite (8 hour TWA)0.1 mg/m3 for respirable cristobalite
Synthetic vitreous fibres (currently listed under synthetic mineral fibres)

1 respirable fibre/mL

5 mg/m3 inspirable dust

(8 hour TWA’s)

0.2 respirable fibre/mL (for refractory ceramic fibres)

1 respirable fibre/mL (for special purpose glass (micro) fibres)

1 respirable fibre/mL (all other SVF’s)

Wood dust1 mg/m3 for certain hard wood dusts (8 hour TWA)1 mg/m3 for hard wood dusts
 5 mg/m3 for soft wood dusts (8 hour TWA)1 mg/m3 for soft wood dusts

Consultation process

Consultation targeted to appropriate stakeholders is an integral part of this current WES review process. Input from industry, unions, health and safety service providers, and academia is an extremely important part of this review.

Of particular importance is air monitoring and exposure data which either supports or opposes the practicable feasibility of achieving the more stringent Standards proposed..

As the Department of Labour does not have ready access to all the exposure monitoring data in New Zealand, this consultation process relies on industry and consultants to state their position, based on their own experiences, regarding the reduction of the Standards. Industry associations are also invited to be part of the consultation process, and the department relies on them to pass this invitation on to their membership, encouraging them to contribute.

All submissions will be reviewed and considered carefully before any final decisions are made in regards to the WES. It is expected this process will take some months.

Figure 1   Standards

RICHARD STEELE is manager technical support services with the Department of Labour’s Workplace Services group.

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