Could your ceramics classroom have exposed you to harmful clay dust?

When most people think of dangerous workplaces, they picture construction sites, mines, or factories. Few would consider a school ceramics classroom. But for anyone who regularly worked with clay, glazes, and kilns, there is a serious and often invisible health hazard: respirable crystalline silica.

Pottery and ceramics were at the height of their popularity in Australian schools throughout the 1970s, 1980s, 1990s, and early 2000s. Teachers who spent years or decades running these programs may only now be developing symptoms of silica-related disease. The long latency period, often 15 to 30 years between exposure and diagnosis, means that many former ceramics teachers now in their 60s, 70s, or 80s could be living with an undiagnosed occupational illness.

Silica is a naturally occurring mineral found in clay, sand, and stone. When clay dries out and is sanded, swept, or handled, or when powdered glazes are mixed, tiny silica particles can become airborne. These particles are fine enough to penetrate deep into the lungs, where they can cause inflammation and scarring and, over time, contribute to cancer and other serious diseases.

Crystalline silica is classified as a Group 1 carcinogen^[1], meaning there is sufficient evidence that it causes cancer in humans. It sits in the same category as asbestos and tobacco smoke.

Who is at risk of silica exposure in ceramics?

You may have been exposed to harmful levels of silica dust if you worked as:

• a ceramics or pottery teacher in a school or TAFE
• an art teacher handling clay materials
• a professional potter or ceramics artist
• a studio technician loading kilns and mixing glazes

Research has found that silica dust can be present in ceramics classrooms at levels that may exceed recommended occupational exposure limits^[2].

Common tasks that can generate silica dust include:

• sanding dry clay before firing
• dry sweeping floors and work surfaces
• mixing powdered glazes
• handling dried clay scraps
• loading and unloading kilns

Dust can also settle on clothing and surfaces, becoming airborne again later. Without proper ventilation, respiratory protection and wet cleaning methods, exposure can accumulate over months and years.

How ceramics teachers may have been exposed to silica dust

In our experience acting for workers with silica-related disease, we have seen cases involving ceramics teachers who worked for years in conditions such as:

• enclosed classrooms with no functional ventilation, windows kept shut in winter, no air conditioning, and no dust extraction
• regular hand sanding of dry clay before firing, generating significant airborne dust that settled across desks, floors, and clothing
• dry sweeping rather than wet cleaning methods, pushing fine silica dust back into the air
• reusing dust-covered lab coats, worn lesson after lesson without cleaning
• mixing dry powdered glazes without respiratory protection or extraction
• no masks, no training, and no warnings, with teachers never told that the materials they were working with contained a known carcinogen
• inadequate systems of work, with little or no assessment of the dust being generated or measures to reduce exposure

In many cases, teachers had no idea that clay contained crystalline silica or that it posed a risk. They may have been given no safety data sheets, hazard training or appropriate protective equipment. They went to work each day and breathed in the dust over months, years, and even decades.

What about asbestos in older ceramics classrooms?

Silica was not the only potential hazard in some older ceramics classrooms.

Some older kilns contained asbestos components, while asbestos-containing fire-resistant materials may also have been used around kilns and in areas where they were installed. This means some ceramics teachers may also have experienced occupational asbestos exposure, depending on the age and type of equipment and the classroom in which they worked.

Anyone who worked around older kilns should include this information when discussing their occupational history with their doctor or lawyer, particularly if they do not know what materials the kiln or surrounding area contained.

Silica content in clay and glaze products

Clay and glaze products commonly used in Australian schools and studios can contain significant amounts of crystalline silica:

• General earthenware: 35–50% silica
• Stoneware: 25-35% silica
• Porcelain: 15–25% silica
• Clear gloss glazes: up to 60% silica^[3]

These figures illustrate why even routine pottery activities can pose a health risk when appropriate controls are not in place.

The link between silica and lung cancer

The scientific evidence linking silica exposure to lung cancer is very strong. A major international study of more than 16,000 lung cancer cases found that risk increased even at very low cumulative silica exposures, with no apparent safe threshold^[4].An Australian study estimated that approximately 10,390 future lung cancers may be attributable to current occupational silica exposure across the workforce^[5].

These risks are not limited to miners and construction workers. Pottery and ceramics teachers can face the same hazard when adequate controls are not provided. Many of these cancers could have been prevented with appropriate workplace protections.

Can smokers claim compensation for silica-related lung cancer? 

Many people think smoking rules them out of a claim, but being a smoker doesn’t necessarily disqualify you from making a compensation claim for work-related lung cancer.

The scientific research is clear: silica exposure increases lung cancer risk independently of smoking. The increased risk persists even after adjusting for cigarette smoking and passive smoke exposure. Silica is a risk factor for lung cancer in its own right, regardless of whether the worker also smoked.

Compensation for silica-related diseases

Many workers and former workers are surprised to learn they may be entitled to compensation for occupational disease, even if:

• the exposure occurred many years ago
• they have since retired or changed careers
• they no longer work for the employer
• they were also a smoker
• the employer is no longer operating

Depending on the circumstances, compensation may cover:

• loss of income, past and future
• medical and treatment costs
• pain and suffering
• care and support needs

What to do if you were exposed to silica as a ceramics teacher

If you have worked with clay, ceramics, or glazes and have been diagnosed with lung cancer, silicosis or another serious condition:

1. See your GP and tell them about your work history, including how long you worked with clay and what tasks you performed.
2. Keep a record of where you worked, what materials you used and what safety measures were, or were not, in place.
3. Seek legal advice. An experienced occupational disease lawyer can help you understand your rights and whether you may have a claim.

If you worked around older kilns, it’s also worth recording what you remember about the kiln, when it was installed or used, and any maintenance, repairs or renovations carried out around it.

We’re here to help with silica exposure claims

Our team has experience helping teachers, tradespeople, and other workers who have developed serious illnesses as a result of workplace exposure to silica, asbestos, and other hazardous substances.

We offer free first consultations and act on a No Win, No Fee basis for workplace disease claims.

If you or someone you care about has been diagnosed with lung cancer, silicosis, COPD, or another serious condition linked to working with clay or ceramics, get in touch today.

Contact our workplace disease team on 1800 111 222.

_{[1] T Sato, T Shimosato & DM Klinman, ‘Silicosis and lung cancer: current perspectives’, Lung Cancer: Targets and Therapy, vol 9, 2018, pp 91–101}

_{[2] Fechser M, Alaves V, Larson R and Sleeth D, Evaluation of Respirable Crystalline Silica in High School Ceramics Classrooms, International Journal of Environmental Research and Public Health (2014), accessed via PubMed Central: https://pmc.ncbi.nlm.nih.gov/articles/PMC3945536/}

_{[3] GL Burgess, ‘Development of an Exposure Matrix for Respirable Crystalline Silica in the British Pottery Industry’ (1998) 42(3) Annals of Occupational Hygiene 209, https://doi.org/10.1016/S0003-4878(98)00005-2}

_{[4] Sato, Shimosato & Klinman, above note 1}

_{[5] R Carey and L Fritschi, The Future Burden of Lung Cancer and Silicosis from Occupational Silica Exposure in Australia: A Preliminary Analysis (Curtin University of Technology, 2022), https://www.curtin.edu.au/about/wp-content/uploads/sites/5/2022/07/FEFreport_formatted.pdf}