New research into asbestos exposure from contaminated children’s play sand has provided important evidence that asbestos fibres can become airborne during normal play activities. The study by Berry et al., published as a preprint in July 2026, tested contaminated craft and moulding sands under controlled simulated play conditions and found detectable airborne asbestos fibres from 90% of the craft sands examined.
The findings are particularly interesting because they move the discussion beyond simply establishing whether asbestos is present within a product. The more important question is whether fibres can actually become airborne and therefore create a potential inhalation exposure.
The research does not establish the level of health risk faced by an individual child, and the authors stress that further research is required. However, the results provide a useful warning about the potential for asbestos exposure from consumer products that might appear relatively innocuous.
Earlier this year, Casa investigated the presence of asbestos fibres within available play sand products and highlighted the absence of air monitoring data as a knowledge gap in the consumer advice being provided. We therefore welcome this study and are keen for other research to contribute furthermore.
What did the play sand study find?
A technician simulating play activities with asbestos contaminated sand, while air monitoring takes place. Photo courtesy of Berry et al. 2026
Researchers in New Zealand tested 15 sand products, including 14 samples that had previously tested positive for asbestos and one asbestos-free control. The researchers classified the products broadly as either loose “craft” sands or more cohesive “moulding” sands (which you may know as ‘kinetic’ sand).
The contaminated products contained either chrysotile, tremolite, or a combination of asbestos types. The research team then recreated different activities that children might undertake when playing with the products, including:
- Pouring and handling the sand
- Digging and burying objects
- Brushing sand from toys
- Building and knocking down sand structures
- Pouring sand through fingers
- Throwing sand into the air
Researchers conducted the experiments inside a purpose-built asbestos enclosure, using an asbestos-trained technician wearing appropriate RPE and PPE. They collected both static and personal air samples and subjected them to Phase Contrast Microscopy (PCM), Transmission Electron Microscopy (TEM) and SEM-EDX analysis.
The results showed detectable airborne asbestos during play with the craft sands. None of the four moulding sands produced detectable airborne fibres, although the researchers caution that this does not demonstrate that moulding sands are completely risk-free.
PCM and TEM results are particularly significant
The air monitoring results warrant careful consideration.
Twenty-one air samples from nine experiments contained detectable asbestos, all associated with craft sands. Transmission Electron Microscopy (TEM) analysis identified asbestos concentrations between 0.0123 and 0.0329 asbestos structures per millilitre (s/ml) of air, while Phase Contrast Microscopy (PCM) results for positive samples reached considerably higher reported fibre concentrations, including results of 0.044, 0.047, 0.053, 0.059 and 0.067 fibres per millilitre (f/ml) of air.
For comparison, the UK uses a 0.01 f/ml clearance indicator following licensed asbestos removal work. Air testing undertaken as part of the four-stage clearance process must demonstrate that airborne fibre concentrations are below this indicator before an asbestos enclosure can be signed off. It is therefore generally accepted that only fibre concentrations below 0.01f/ml are considered ‘satisfactory’, although the Health and Safety Executive state that there is no safe level of asbestos exposure.
That makes several of the reported results noteworthy: a number of the study’s PCM and TEM results exceeded 0.01 f/ml, with some results moving substantially closer to the UK’s asbestos Control Limit of 0.1 fibres/ml.
The highest PCM result reported in the study was 0.067 f/ml, while the highest TEM concentration was 0.0329 s/ml.
It is important not to scientifically interpret these figures as directly equivalent to occupational exposure measurements or a licensed asbestos removal clearance test. The study used different scenarios, sampling durations, analytical methods and experimental conditions.
Nevertheless, the comparison provides relatable context for the consumer. The results demonstrate that the concentrations measured during simulated play were not simply trace findings below conventional asbestos clearance criteria.
This table shows the reported PCM fibre concentrations ranked in comparison with the 4-Hour Control Limit and the Clearance Indicator
Why the results need to be interpreted carefully
There are important limitations to the research. The researchers explain that the large amount of dust generated by the sand caused significant filter loading; this reduced the airflow rate of many sampling pumps to approximately 3 litres per minute, resulting in relatively imprecise limits of detection.
This matters because a lower volume of air passing through a filter means that the laboratory has a smaller air sample from which to identify fibres. Consequently, the study’s limits of quantification (LOQ) were higher than would typically be desirable for this type of airborne asbestos testing. It could be queried as to why pooled samples were not used alongside higher field counts in order to lower the LOQ of each sample, but it is important to remember that operational guidance is different in New Zealand to the UK (though there are many similarities).
A negative result therefore does not necessarily demonstrate that asbestos fibres weren’t released. It only demonstrates that fibres were not detected above the applicable detection limit.
This limitation particularly affects interpretation of the moulding sand results. None produced detectable airborne asbestos, but the researchers specifically state that this should not be taken as proof that no risk exists. The study also did not establish what might happen as moulding sand dries out over time.
The study also used products that had already been distributed and, in some cases, used by members of the public. The researchers acknowledge that some of the finer fibre fraction may already have escaped before testing, potentially causing the experiment to underestimate fibre release.
Finally, this is currently a preprint and has not been peer reviewed, so its findings should be considered preliminary.
What does this mean for asbestos exposure?
The research does not allow us to calculate the future health risk to a particular child who has played with contaminated sand.
This distinction matters; detecting asbestos fibres in the air demonstrates the potential for exposure, but it does not tell us the cumulative dose inhaled by an individual or translate directly into a quantified lifetime disease risk.
However, the researchers make an important practical observation: airborne asbestos during normal use is not an acceptable characteristic for a children’s consumer product. Following the hierarchy of controls for protection against risks, the most effective way to eliminate continued exposure is simply to stop using contaminated products – this is particularly relevant given that the issue has resulted in countless product recalls internationally so far, with more recalled each week.
What should consumers do with contaminated sand?
The UK’s Office for Product Safety and Standards (OPSS) has published specific guidance for consumers and businesses following the discovery of asbestos in sand-containing products.
The Government advises consumers to stop using recalled products immediately. If the sand remains in its packaging, OPSS recommends placing it in a heavy-duty plastic bag, securely double-taping and clearly labelling it before storing it somewhere inaccessible to children.
Where contaminated sand has already been used, OPSS recommends cleaning affected areas using wet cloths to avoid generating dust, double-bagging the sand and cleaning materials, and keeping children and other people away from the area until cleaning has taken place. Consumers should then follow the relevant retailer’s recall arrangements or contact their local authority for advice about safe disposal.
Consumers should also check the current OPSS Product Safety Alerts, Reports and Recalls information rather than assuming that a product is safe simply because they have not heard of a recall.
Don’t assume an unlisted product is necessarily safe
This is perhaps one of the most important messages arising from the research.
The study could only test a limited selection of products and explicitly states that its findings cannot be generalised to every play sand product.
At the same time, the UK Government has acknowledged an increasing number of asbestos-contaminated sand-containing consumer products and has told businesses that they must have appropriate controls throughout their supply chains.
For consumers, that means a sensible precautionary approach is warranted. If a similar sand product has not been officially recalled, that does not necessarily constitute proof that it is asbestos-free. Consumers with concerns about a product that has not been recalled should follow the OPSS advice and contact the appropriate consumer protection authority.
The emerging evidence around asbestos-containing play sand demonstrates why identifying contamination within a product is only the first step. Understanding whether that asbestos can become airborne during normal use is equally important.
As the research develops, further studies should help establish how different sand types, fibre concentrations, moisture levels and play activities influence airborne fibre release. Until then, following official recall and disposal advice remains the most effective way for consumers to prevent further asbestos exposure from contaminated products. Check in with our News page regularly for more updates.
