Health and Safety

Taking care with materials, equipment and work procedures and dealing with hazards.

Airborne and other pollutants

Airborne and other pollutants may not be obvious, but exposure to them can be extremely dangerous. Past exposure to asbestos is the single-biggest cause of work-related death in Aotearoa New Zealand today, accounting for an estimated 220 deaths each year. Silica dust is also a risk on construction sites.

Pollutants from building sites include:

A measure of the danger

WorkSafe statistics show that cancers and respiratory diseases from all airborne substances account for around a third of the total burden of work-related harm in New Zealand. They account for an estimated 650 deaths per year, more than three-quarters of the total number dying from work-related causes.

The New Zealand Carcinogens Survey, the first survey looking at carcinogens (substances that can cause cancer) in the working population, found that construction workers are one of the three occupational groups exposed to the highest average number of carcinogens. Carcinogens include substances such as crystalline silica and wood dust.


Masks and respirators

Masks and respirators protect you when you are sanding, cutting, spraypainting, paint stripping, or carrying out other tasks that produce dust or fumes that could be harmful – demolition is an obvious example. There are different types of mask for different hazards and different levels of protection. Some come with exhalation valves to stop hot air buildup against your face and are more comfortable to use.

Unvalved P1 mist/dust mask

These masks are suitable for nuisance dust or mist sprays that are non-toxic or of very low toxicity. They don’t give protection against gases or solvent fumes.

Valved P2 toxic dust mask

These masks are suitable for cutting/sanding timber as well as welding and brazing.  They will not protect against toxic gases or fumes, although some have added features that reduce the nuisance levels of gases, vapours and oil-free aerosols.

Half-mask respirator

These masks have changeable filters and pre-filters for protection against paint mists and vapours – select the appropriate filter for the job.

  • Chemical filters are available to protect against solvent fumes from things like degreasing fluids, thinners, lacquers and enamel paints.
  • P2 toxic dust filters protect against fine dust and welding fumes.
  • P3 filters protect against more highly toxic fumes and particles.
  • Many other types of filter and pre-filter are available – seek advice from a specialist supplier

Half-masks are not suitable for use in highly toxic areas or if the paints contain iso-cyanates. In these cases use a full mask with air supply.

WorkSafe points out that you need to be clean shaven when you’re wearing a mask or respirator for it to form a proper seal and give effective protection. It has a Life Shavers campaign with more details.

WorkSafe also has a Respirator selection tool on its website.

On-tool extraction

Another key approach to reducing on-site risks from construction dusts is on-tool extraction. These are systems that are fitted directly onto power tools to remove dust. There is a hood that captures the dust as it is created, a hose and an extraction unit that sucks up the dust and stores it safely.

Typically, tools with exhaust ventilation are supplied as complete systems, but in some cases systems can be switched between tools. When buying a system, check that it will be able to handle the type of dust produced:

  • L Class – low risk
  • M Class – medium risk
  • H Class – high risk.


Updated: 04 July 2023