Air Matters participated in the recent review  of the Workplace Exposure Standards that were submitted for review by Worksafe in June 2018.

Air Matters was involved in these reviews via four different perspectives; clients, professional societies and consultants. The wide-ranging scope of the work we are involved with meant we had a good understanding of the impact these changes will likely have on workplaces into the future.

The proposed changes are a positive move based on recent scientific studies that will work towards keeping workers healthy and able to go home from work each day without concern of long term health implications.

Air Matters see the challenges faced by these proposed new levels as being the ability for industry to comply. In some cases, the cost of implementing changes will be significant but in others the change reflects a more realistic standard that many already achieve. The challenges faced by some may be difficult to deal with initially but are seen as a necessary step to protect worker health.

The new proposed standards come from a scientifically robust analysis of international studies that relates to actual health effects. The older standards for all substances in this round of review were clearly out of date and often not protecting the health of workers enough, especially over longer periods of time.

The fifteen workplace exposure standards reviewed are summarised in the table below.

Table 1: Table of Workplace Exposure Standards reviewed in June 2018.

Flour dust Beryllium Portland Cement
Hydrogen sulphide Chromium VI Synthetic mineral fibres
Nitrogen dioxide Cobalt Sulphuric acid
Propylene oxide Manganese Welding fume
Styrene Nickel
x17 BEIs Perchloroethylene

Of the fifteen workplace exposure standards reviewed Air Matters are commonly involved with those bolded in the table above. In addition to the workplace exposure standards there were also seventeen biological exposure indices (or measurement of levels in urine, breath or blood) that were reviewed. Air Matters are not commonly involved with this type of measurement so did not comment.

Air Matters commonly measure exposures to substances through inhalation. In this case the chemical needs to be airborne as a gas, fume, mist or particulate. However, many of these substances also have skin notations associated with them which also means that they have a health effect through contact with skin and any other extremities, such as eyes and nose.

The fifteen substances were reviewed through a standardised set of questions that remained very similar for each substance. These questions generally covered being able to comment on the new level, any new or added notations, the feasibility of meeting the new WES and the ability to be able to sample for the new levels. The most interesting of the substances reviewed based on the experiences of Air Matters staff were nitrogen dioxide and welding fume.

The nitrogen dioxide standard is proposed to drop from 3 ppm (WES-TWA) to 0.2 ppm (WES-TWA). This is a significant drop and will likely impact significantly on a client we represent. The other quirk to this change was the complete removal of the short-term exposure limit (STEL). There is nothing in its place except a heavy reliance on the excursion limits, which was always seen as general guidance in the absence of an alternative rather than a standard itself.

The proposal to remove the welding fume standard was also an interesting concept to be able to comment on from Air Matters point of view. On one hand it seems a reasonable change to make due to the standard not being a combination of substances and having no direct health protecting effect. However, on the other hand it serves a great purpose as a simple guide for industry with the ability to measure a much easier option than the alternatives. This type of standard needs knowledge of the type of exposure to be used well and we can see that the proposed removal is making sure that it is not misused.

Air Matters welcomed being able to contribute to something that will have a long-lasting impact on worker health in New Zealand. Occupational hygiene is all about protecting worker health so these standards are a vital tool in the assessments we undertake each day.

We look forward to the next round of reviews that will likely take place in the near future!