LADRA Limited

Asbestos / Asbestoid / Asbestiform – Is there a difference and does it matter?

Posted by Luke Austin on 11 March 2018 | 0 Comments

Tags: Asbestos, Asbestoid , Asbestiform, actinolite, grunerite, amosite, anthophyllite, chrysotile, crocidolite , tremolite, Antigorite, Erionite

Introduction and regulatory position

People involved with asbestos will be aware that there are six regulated types, and in New Zealand these are defined in Regulation 3 (1) of the Health and Safety at Work (Asbestos) Regulations (2016) (Asbestos Regulations).

“Asbestos means the asbestiform varieties of mineral silicates belonging to the serpentine or amphibole groups of rock-forming minerals, including the following:

(a)   actinolite asbestos

(b)   grunerite (or amosite) asbestos (brown)

(c)   anthophyllite asbestos

(d)   chrysotile asbestos (white)

(e)   crocidolite asbestos (blue)

(f)    tremolite asbestos

a mixture that contains 1 or more of the minerals referred to in paragraphs (a) to (f)” (Ministry of Business, Innovation, and Employment, 2016)

The definition supplied requires the public to treat all these types of asbestos equally, however it also suggests that any other type of asbestiform mineral has no risk.

This blog will endeavour to provide some information around the following:

(1)   How many types of asbestiform minerals are there?

(2)   What is the difference between asbestos, asbestoid, and asbestiform?

(3)   Why do we only specifically regulate six, and what is the consequence of that approach?

(4)   What should we do about it?

How many types of asbestiform minerals are there?

While people may think that only the six named minerals are fibrous, there are close to 400 different minerals which naturally have a fibrous form, see Table 1 below. All these are asbestiform minerals, as they have the form or appearance of asbestos. (Merriam-Webster, n.d.)

The non-Regulated Asbestiform minerals are often called Asbestoids, meaning they resemble asbestos. (Merriam-Webster, n.d.)

What is the difference between asbestos, asbestoid, and asbestiform?

From a mineralogical, and potentially a health point of view, there is no real difference between the three as all can form fibrous material. It is the Regulatory view point that provides the real difference. The simple definitions are:

1. Asbestiform: A mineral that has a natural fibrous form, and there are about 400 different minerals contained in this wide group.
2. Asbestos: The six Regulated Asbestiform minerals.
3. Asbestoid, The Non-Regulated Asbestiform minerals.

Why do we only specifically regulate six, and what is the consequence of that approach?

“The term asbestos is a commercial-industrial term rather than a mineralogical term. It refers to well-developed and hairlike long-fibered varieties of certain minerals that satisfy particular industrial needs.” (National Research Council (US) Committee on Nonoccupational Health Risks of Asbestiform Fibers., 1984)

In the 1970’s when asbestos regulations were starting to be formalised attention was only placed on those minerals that were deemed (at that time) to have a commercial application, and therefore potentially placing the public at risk. (Fitzgerald, 2014, p. 43)

This commercial focus has meant that Regulatory attention has only been placed on those six specific minerals due to their commercial uses, irrespective of any specific (known or unknown) health concerns regarding the balance of the approximate 370 other fibrous minerals in existence.

A perverse affect of this 1970 based approach is that as we (as a population) have restricted, via Regulations, the use of the six types of asbestos, we (as a population) have started to look at the remaining fibrous minerals to determine what commercial applications that they might have. Antigorite, which is found in New Zealand (Mindat, n.d.), is being targeted as a potential mineral to assist in carbon dioxide sequestration, amongst others. Recent research indicates that Antigorite has similar toxic properties to those already known for asbestos. (Fitzgerald, 2014, p. 43)

Furthermore, Baumann et al. state: “Erionite is regarded as the most potent carcinogenic mineral fibre, but is not defined as asbestos and is therefore not regulated, underscoring the problems caused by the present nomenclature and legislation.” (Baumann, 2013, p. 577)

So, there is the potential that we (as a population) by focusing our attention on only the six regulated are being blinded to the health risks posed by other asbestiform fibres. Asbestos Surveys will not pick the presence of these fibres up as Asbestos Analytical laboratories will generally not have the methods to identify them. When it comes to Clearance Certificates, Asbestos Assessors are only providing Clearance against the six Regulated asbestos fibres.

What should we do about it?

The asbestiform fibres that are not regulated will still produce fibres that may be sized within the respirable range. The membrane filter fibre counting methods relies on counting fibres that meet certain geometric properties of the respirable range. (National Occupational Health and Safety Commission, 2005, p. 15). This means that if someone is undertaking air monitoring in an area where exposure to these non-regulated fibres are known to located, there is the potential that they will be counted, and the result will stand.

Where there is the potential for harm due to a high respirable fibre count from non-regulated asbestiform fibres reference should be made to Health and Safety at Work (General Risk and Workplace Management) Regulations 2016 and there are two specific regulations that are relevant, these are set out below:

“5     Duty to identify hazards

A PCBU, in managing risks to health and safety, must identify hazards that could give rise to reasonably foreseeable risks to health and safety.

28    Managing risks associated with substances hazardous to health

(1)        A PCBU must manage, in accordance with regulations 5 to 8, risks to health and safety associated with substances hazardous to health at the workplace.

(2)        A PCBU who contravenes this regulation commits an offence and is liable on conviction, -

(a)    for an individual, to a fine not exceeding $10,000:

(b)    for any other person, to a fine not exceeding $50,000.” (Ministry of Business, Innovation and Employment, 2016)

As there is evidence that shows that specific asbestiform fibres are toxic to human health, then we must manage this risk appropriately. Regulation 5, above, means that while the use of these asbestiform fibres may be allowed (as they are not specified in the Asbestos Regulations) this does not relieve the obligations on PCBU’s to main a safe place to work.

In most situations the method of managing the risk to human health from non-regulated asbestiform fibres will be identical to that for the six regulated asbestos fibres.

Bibliography

Baumann, F. A. (2013, June). Asbestos is not just asbestos: an unrecognised health hazard. Lancet Oncology, 14(7), 576-578. Retrieved from http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(13)70257-2/abstract

Fitzgerald, S. H. (2014, August). Antigorite. Is it the forgotten asbestos? Professional Safety, 59(8), 43 - 48. doi:https://www.onepetro.org/journal-paper/ASSE-14-08-43

Merriam-Webster. (n.d.). Dictionary. Retrieved 07 March, 2018, from Merriam-Webster: https://www.merriam-webster.com/dictionary/asbestoid

Merriam-Webster. (n.d.). Dictionary. Retrieved 07 March, 2018, from Merriam-Webster: https://www.merriam-webster.com/dictionary/asbestiform

Mindat. (n.d.). mindat.org. Retrieved 08 March, 2018, from mindat.org: https://www.mindat.org/locentry-829.html

Ministry of Business, Innovation and Employment. (2016). Health and Safety at Work (General Risk and Workplace Management) Regulations 2016. Retrieved 06 March, 2018, from New Zealand Legislation: http://www.legislation.govt.nz/regulation/public/2016/0013/latest/DLM6727572.html

Ministry of Business, Innovation, and Employment. (2016). Health and Safety at Work (Asbestos) Regulations 2016. Retrieved 05 March, 2018, from New Zealand Legislation: http://www.legislation.govt.nz/regulation/public/2016/0015/19.0/DLM6729706.html

National Occupational Health and Safety Commission. (2005). Guideance Note on the Membrane Filter Method for Estimating Airborne Asbestos Fibres 2nd Edition. (C. o. Australia, Ed.) Retrieved 06 March, 2018, from Safework Australia: https://www.safeworkaustralia.gov.au/system/files/documents/1702/guidancenote_membranefiltermethodforestimatingairborneasbestosfibres_2ndedition_nohsc3003-2005_pdf.pdf

National Research Council (US) Committee on Nonoccupational Health Risks of Asbestiform Fibers. (1984). Asbestiform Fibers: Nonoccupational Health Risks. (The National Academies Press) Retrieved 05 March, 2018, from National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/books/NBK216753/