Skip over navigation
New Zealand Plumbers, Drainlayers & Gasfitters Association Inc

New Zealand Plumbers, Drainlayers & Gasfitters
Association Inc

Latest News / Top Tech Tip - Silicosis

Silicosis and the risks of working with engineered stone bench tops used primarily in bathrooms and kitchens.

Silicosis is an irreversible and progressive disease that causes fibrosis of the lungs from the inhalation of respirable crystalline silica (RCS).  RCS is produced when engineered stone (which contains up to 95% crystalline silica) is cut, ground, drilled or polished. Trades persons need to become aware of the issues and the control strategies available to minimize the likelihood of workers being exposed to RCS.

The majority of the dust particles making up the RCS are too small to be seen with the naked eye, however the fine particles are often associated with larger-sized particles that are visible.  In addition to accelerated silicosis, exposure to RCS can also cause lung cancer, chronic obstructive pulmonary disease (COPD) and kidney disease.

Confirmed cases of silicosis, associated with engineered stone bench top work, have been identified in Queensland, Australia and in the vast majority of cases, the workers displayed no symptoms.  Many of these cases have been consistent with accelerated silicosis – a form of the disease that develops over a short period (1 to 10 years) due to the inhalation of very high concentrations of RCS. 

The prevalence of the disease in New Zealand is currently not known, but WorkSafe wishes to raise awareness of the risks to health of working with engineered stone and of the controls that should be used to ensure this work can be done safely.
The finished bench tops themselves do not present a risk to health once they are installed, provided they are not cut, ground, drilled or polished.  Those at risk of exposure to RCS include:
  1. Workers who fabricate these bench tops without adequate controls in place (WorkSafe has already engaged with the engineered stone bench top fabrication industry to raise awareness); and
  2. Others who may modify the bench tops as a part of the installation process OR, to accommodate new fittings such as cook tops, into existing engineered stone bench tops.
If a trades person is uncertain about whether or not a bench top is made from engineered stone, they should, so far as is reasonably practicable, find this out by asking the principal contractor, designer, or homeowner.  Where uncertainty remains, it should be assumed that the bench top is made from engineered stone, and appropriate controls implemented as discussed in the resources below.  It is noted that bench tops made from other stone materials (such as granite) still contain crystalline, albeit at lower concentrations than in engineered stone, so the same controls can be used to minimize exposure to RCS.

How do you know if you have silicosis?
Symptoms of silicosis are:
  1. Cough is an early symptom and develops over time with exposure to inhaled silica.
  2. In acute silicosis, fever, sharp chest pain, and difficulty breathing can come on suddenly.
  3. You may see phlegm production.
  4. You may hear wheezing and crackling sounds in your lungs.

What is silicosis disease?
Silicosis is an interstitial lung disease caused by breathing in tiny bits of silica, a common mineral found in many types of rock and soil.


Does silicosis go away?
Silicosis cannot be cured, but its progression can be slowed if exposure to silica is avoided, especially at an early stage of the disease. A whole lung lavage (washing) can be used to treat both acute and chronic silicosis.

How long can you live with silicosis?
The survival times of silicosis stage I , II and III, from the year of diagnosis to death, were 21.5, 15.8 and 6.8 years, respectively. There was 25 % of the silicosis patients whose survival time was beyond 33 y. The mean death age of all silicosis cases was 56.0 y.

The following guidance material is available on the WorkSafe website, and it covers what silica dust is, and how the risks of exposure can be effectively controlled.
WorkSafe is also working with the industrial and commercial vacuum industry to develop guidance for those wishing to use vacuum methods to remove hazardous dusts, such as RCS.  Once completed, this will be made available on the WorkSafe website
WorkSafe is supporting the New Zealand Occupational Hygiene Society (NZOHS) with the development of the “Breathe Freely New Zealand” (BFNZ) programme.  The website ( will be launched in early July 2020 and guidance material on that site includes material developed for specific trades (including stonemasons, plumbers, carpenters/joiners, electrical engineers/fitters) as well as more general material on crystalline silica.  WorkSafe encourages individuals and organizations to access BFNZ resources as they complement the material from WorkSafe New Zealand, listed above.

  • NZ Certified Builders
  • Franklin
  • Aqualine
  • Aquatica
  • Crombie Lockwood
  • Konnect
  • Licensed NZ
  • Rinnai
  • Terra Cat
  • BP Connect
  • Reflection Water Treatment
  • System Control Engineering
  • AIL
  • Galpro