News coverage¹ of asbestos fibres detected in children’s crayons this month may have come as a surprise to some in Australia but the contamination problem has been known for much longer. Back in August 2000, the Consumer Product Safety Commission (CPSC) in the USA² released a report detailing that asbestos fibres had been detected in a range of children’s crayons, manufactured locally and imported. The Australian Competition and Consumer Commission (ACCC) released a statement this week³ on the asbestos crayons analysed in Australia.
Although both the CPSC and the ACCC reports asserted that the risk was low based on air monitoring during typical use and that “asbestos in fixed within the crayon wax”, the CPSC stated that “…as a precaution, crayons should not contain these fibres.”
Typical use, as stated in the CPSC report, only amounted to ’30 minutes continued drawing’ and did not look at any ageing effects of the wax breaking down and potentially releasing fibres with time. Paraffin wax, commonly used in crayons, degrades and dries with time potentially releasing more fibre than this original testing was able to quantify.
Asbestos fibre concentration within the various crayons that have been tested to date have been stated as either 0.03%² or ‘low’³. This is not necessarily a useful figure if it is not stated as a weight percent of the original crayon or of the filler/inorganic material within the wax – 0.03 wt % of the entire crayon may represent 5 % of the filler material, which may be all that’s left should a crayon break down under UV exposure, be thrown in a fire/incinerated or used on a surface which is prone to abrasion eg concrete floor. As stated by Crayola⁶, kids ‘on average’ will have worn down 730 crayons by their 10th birthday. These figures indicate young children may potentially be exposed to up to 10g of asbestos fibre.
The issue has arisen from contaminated filler material within the crayon – commonly talc (talcum powder) which is a magnesium silicate mineral historically mined in areas that have geological variations/impurities present, such as asbestos. Careful selection of quarried material for commercial products such as personal hygiene cosmetics/talc has been an issue in the past with various cases of lung cancer and mesothelioma associated with contaminated talc⁴ found to contain chrysotile and tremolite.
Crayons analysed using a full dissolution, scanning electron microscopy technique at Microanalysis Australia’s laboratory recently found significant⁵ concentrations of tremolite and chrysotile. The image above is of a highly asbestiform, tremolite fibres with an aspect ratios of > 100:1 and diameters < 0.3 µm. Many of the finer fibres (< 0.5 µm) would not be detectable via optical techniques.
Testing continues at Microanalysis to reveal the extent of contamination in crayons sold throughout Australia.
Feeling the love – Messages from the Telstra Business Awards Night
The Telstra Business Awards Night may be a distant memory for us now and the fuzzy heads have cleared, however we wanted to share with you all our messages of support from the evening.
Thank you to everyone who has been a part of Microanalysis over the last 7 years.
Congratulations on your achievements at the Telstra Business Awards! We hope you had a great night celebrating your success.
As a keepsake, we’d love to share with you your supporter messages that were screened on the night:
Arms, legs, fingers and toes crossed for you all. Remember someone needs to stay sober for the acceptance speech. X – Heather
Congratulations on this recognition of the amazing success you have achieved through the application of your expertise and your determination! – Bronwyn Baker
Congratulations Rick, Debbie & the Microanalysis Australia team on reaching the TBA finals. – John Warmington, Technology Incentive Services
Congratulations to Nimue and the rest of the Team, all the best and hope you win the award – Stephen Fennell
Congratulations to Rick, Debbie and team. I could see your success reflected in the faces of your workforce. A shared adventure! – Reg Hill FCA, MBA.
Good luck to Rick, Debbie and the whole Microanalysis Australia crew! Best scientists in the business.- Phill English
Good luck to you Microanalysis Australia. – Sue Doherty
Microanalysis is a brilliant business built by an outstanding team. You are most deserving of this nomination. Go Rick, Debbie and team! – Bec Shillington
Taking the leap is a beginning, keeping together is progress, working together is success. Congratulations Microanalysis Australia! – Mia, Jez & Ella
Your nomination is a wonderful achievement! We share your happiness on this special occasion. – Mia, Jez & Ella
To Rick, Debbie and the Team at Microanalysis Australia, Well done to all of you in having your passion and professionalism recognised tonight. Good Luck! From The Team at Datatech Solutions
The Australian Mining Review
Microanalysis recently appeared in an article in the September edition of The Australian Mining Review in the XRF & XRD Technology section.
Thank you Jane Goldsmith for a great article about our team.
Actinolite has commonly been acknowledged to be a less hazardous form of asbestos. But longitudinal studies show that shorter and thinner fibres may be just as hazardous – and that the fibre size might be too thin to be detected by standard optical techniques!
Cracker dust (also known as crusher dust or quarry fines) is finely crushed blue metal or other aggregate rock which is commonly used as a base for roadways, paths, as a screed for landscaping or for hardstand areas. It is known for its good compaction properties.
Cracker dust supplied from two quarries in the Pilbara has historically been known¹,³, to inadvertently contain actinolite asbestos mineral fibre at low concentrations. Actinolite (CAS # 12172-67-7)⁶, an amphibole asbestos mineral with the chemical formula [Ca2(Mg,Fe2+)5Si8O22(OH)2]n can occur in both asbestiform (low diameter and high aspect ratio) and non-asbestiform (cleavage fragment) morphologies. All forms of asbestos (chrysotile, crocidolite, amosite, tremolite, actinolite and anthophyllite) as well as other highly acicular mineral fibres (richterite, erionite, winchite, fluoro-edenite) are classified as group 1 human carcinogens².
Actinolite is an intermediate-member mineral of the solid-solution series from the magnesium-rich tremolite to the iron-rich ferro-actinolite. The International Agency for Research on Cancer (IARC) quotes a study conducted in 1989 by Pott et al⁹., which concludes that relatively low concentrations of fibrous actinolite dust had significant impacts on the tumour incidence in intrapleural experiments on rats. Similar dust loadings with blue asbestos, otherwise known as crocidolite (Davis et al., 1991, Roller et al., 1996) have shown comparable levels of tumour incidence in rats. Studies by Cook, P. et al.,(1982)¹⁰ suggest ferroactinolite is more potent to health compared to amosite/grunerite (brown asbestos).
To date there has been limited epidemiological research conducted into the health impacts of different morphologies of asbestos fibres. NIOSH, 2009⁴ and Dodson et al., 2006⁵ showed that fibre aspect ratio and size play an associated role in fibre-diseases development – asbestosis being correlated with the surface area of biopersistant fibres, – fibrosis with fibres > 2 µm long, – mesothelioma with fibres longer than 5 µm and thinner than 0.1 µm (below optical resolution limits), – lung cancer with fibres longer than 10 µm and thicker than 0.15 µm². Composition (particularly iron) and biosolubility are also known to be influencing factors in a fibre’s potency.
Whilst there is evidence to show that actinolite from cracker dust in the Pilbara has morphologies indicative of cleavage fragments, there is also evidence that shows several nodes of highly asbestiform morphologies were associated with road base and pathway fill constructed from this quarry dust (see figure 1) – d50 diameter, 0.4 µm, aspect ratio >15:1. Recent evidence published by F. Baumann et al.,(2011)⁷ from the study of asbestos containing road base material in New Caledonia, has suggested a correlation between low concentration serpentinitic (chrysotile/antigorite) containing road base fibres and mesothelioma. According to the article, short fibres such as antigorite are not usually taken into account in air monitoring analyses due to their lower aspect ratio. An article published by Suzuki Y et al.( 2005)⁸, suggests shorter fibres may in fact contribute to mesothelioma, contrary to currently accepted paradigms.
⁴ NIOSH (2009). Asbestos fibres and other elongated mineral particles: state of the science and roadmap for research Report. Department of Health and Human Services, Public Health Service, Centers for Disease Control.
⁵ Dodson RF & Atkinson MA (2006). Measurements of asbestos burden in tissues. Ann N Y Acad Sci, 1076
⁶ USGS (2001). Some Facts about Asbestos (USGS Fact Sheet FS-012–01), 4 pp
⁸ Suzuki Y, Yuen S, Ashley R. 2005. Short, thin asbestos fibers contribute to the development of human malignant mesothelioma: pathological evidence. Int J Hyg Environ Health 208:201–210
⁹ Pott F, Roller M, Ziem U et al. (1989). Carcinogenicity studies on natural and man-made fibres with the intraperitoneal test in rats. IARC Sci Publ, 90: 173–179. PMID:2744824
¹⁰ Cook, P. et al.,(1982). Interpretation of the carcinogenicity of amosite asbestos and ferroactinolite on the basis of retained fibre dose and characteristics in vivo, Toxicology Letters, 13 (1982) 151-158.
We can help you find out what it is and where it came from.
Identifying an unknown sample is always an entertaining challenge. Without any idea of the origin of a sample, the first step is visually assessing the most appropriate analytical technique (smell and texture can help too). From there we can pick which technique or series of techniques will be the most appropriate.
Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM EDS) can be used the determine the elemental composition of the unknown and the morphology (shape) of the particles. Sometimes this is enough to identify the material and the possible origin.
X-ray Diffaction (XRD) is appropriate for crystalline samples, materials where the atoms form a repeating pattern. We choose to do XRD if the material appears clearly crystalline or if the SEM indicates that the material is likely crystalline and that the elemental composition could indicate the presence of multiple substances. XRD will give the type and relative concentrations of the crystalline phases in the unknown.
Fourier Transform Infra-red Spectroscopy (FTIR) is able to identify certain organic compounds, so if the SEM shows an elemental composition indicative of an organic substance (or if the initial assessment shows that the unknown is likely organic) then FTIR could help to identify it.
We also have a wide range of other techniques at our disposal, including GCMS, ICP, XPS, BET, Brightness/Colour and much more. Each step of the way, we assess what we’ve found out and what the next step should be, if there even needs to be one.
We transform a complete unknown to a story to be told.
sen from contaminated filler material within the crayon – commonly talc (talcum powder) which is a magnesium silicate mineral historically mined in areas that have geological variations/impurities present, such as asbestos. Careful selection of quarried material for commercial products such as personal hygiene cosmetics/talc has been an issue in the past with various cases of lung cancer and mesothelioma associated with contaminated talc⁴ found to contain chrysotile and tremolite.
