1. Copyright Resources Safety,Department of Mines and Petroleum
Fibrous minerals and dust – managing the risks Part 1 Dust and mineral fibre exposure

2. Please read this before using presentation
This presentation is based on content presented at the Exploration Safety Roadshow held in December 2010
It is made available for non-commercial use (e.g. toolbox meetings) subject to the condition that the PowerPoint file is not altered without permission from Resources Safety
Supporting resources, such as brochures and posters, are available from Resources Safety
For resources, information or clarification, please contact:
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3. Copyright Resources Safety,Department of Mines and Petroleum
Dust emissions from drilling operations may contain some very hazardous material
These may include nickel, mercury, lead, manganese and carcinogens such as quartz and certain types of mineral fibres
Dust composition is often unpredictable and health effects from exposure can be delayed
Chris White will discuss drilling and dust from an OH perspective
I will focus on mineral fibres and why we should be concerned about them

4. Copyright Resources Safety,Department of Mines and Petroleum
Why mineral fibres?
Rising demand for State’s minerals so some previously uneconomic orebodies containing fibrous minerals are now commercially viable
Increased probability of encountering fibrous minerals as depths of exploration and mining increase
All airborne fibrous minerals have some health implications
Fibrous minerals have always been around. Why should mineral fibres be on our radar when doing risk assessments?
Increased opportunity to encounter fibres either because of the ore type or simply the amount of ground being accessed.
It’s important to be aware that all mineral fibres may be harmful, not just those that we hear about most often, such as asbestos.

5. Copyright Resources Safety,Department of Mines and Petroleum
Recent release
Guideline - Management of fibrous minerals in Western Australian mining operations
Help mining industry understand hazards
Risk-based approach
Fibrous minerals management plan
Recent release “Management of fibrous minerals in Western Australian operations”
Replaces asbestos publications
Greater emphasis on a risk based approach - recommendation for a Fibrous Minerals Management Plan
Employers’ duty to ensure exposure of workers to airborne fibrous minerals within regulatory standards, and workers’ rights to know about workplace hazards, access to information and training outlined in guidelines?

6. Copyright Resources Safety,Department of Mines and Petroleum
Mineral fibre types
Asbestos “Asbestiform minerals”
Erionite
Winchite
Brucite
Rickterite
Pyrolusite
Many others

7. Asbestiform and non-asbestiform minerals
Copyright Resources Safety,Department of Mines and Petroleum
Asbestiform and non-asbestiform minerals
Asbestiform riebeckite
Non-asbestiform riebeckite

8. Copyright Resources Safety,Department of Mines and Petroleum
Types of asbestos

9. Asbestiform fibre types
Copyright Resources Safety,Department of Mines and Petroleum
Asbestiform fibre types
Crocidolite
(Amphibole)
Chrysotile
(Serpentine)

10. Copyright Resources Safety,Department of Mines and Petroleum
Origins of asbestos
Parent rock is mafic or ultramafic (igneous)
Disturbance in rock formation (e.g. faulting, slippage)
Heat, pressure, water and minerals from parent rock lead to asbestos crystal formation
Often occurs in “lenses” or bands (mm – cm)
Mineral deposits with asbestos present include iron ore, nickel sulphides

11. Asbestos minerals probability
Copyright Resources Safety,Department of Mines and Petroleum
Asbestos minerals probability
This is a very general map and really just illustrates that understanding the geology of the area is important so you are aware of what minerals might be encountered.

12. Pros and cons of asbestos
Copyright Resources Safety,Department of Mines and Petroleum
Pros and cons of asbestos
Useful properties
Fibrous morphology
Durable
High tensile strength, flexible
Heat and corrosion resistant
Low electrical conductivity
Detrimental aspects
Health implications from inhalation of airborne fibres

13. Why are mineral fibres hazardous?
Airborne and respirable size (low micron)
Morphology (long and thin)
Persistence in the lung (insolubility of fibres and macrophages)
Interaction of fibres with lung tissue to induce free radical formation

14. Respiratory system – particle size

15. Alveolar region of lung

16. Copyright Resources Safety,Department of Mines and Petroleum
Health effects
Asbestosis
Lung cancer
Mesothelioma
Plural plaques
Type of asbestos inhaled is important factor in determining which lung disease may develop
crocidolite (blue) > amosite (brown) > other amphiboles >> chrysotile (white)

17. Exposure to asbestos fibre
Typical non-occupational exposure is fibres/mL
National exposure standard (TWA) is 0.1 fibres/mL (any form of asbestos)
Humans breathe 10 to 20 m3 of air per day
10 m3 of air = 1,000 respirable fibres breathed per day
About 25,000,000 fibres inhaled in a lifetime

18. NOHSC:3003 (2005) Membrane Filter Method Light microscopy
Exposure measurement
NOHSC:3003 (2005) Membrane Filter Method
MSIR b (iv) and 9.33 (2)
Light microscopy
Electron microscopy (SEM, TEM)
Direct reading instruments

19. Respirable fibre definition
Copyright Resources Safety,Department of Mines and Petroleum
Respirable fibre definition
Widely used definition
< 3 µm diameter
> 5 µm long
> 3:1 aspect ratio
Mining definition in WA [MSIR 9.33 (3)]
Maximum width  1 µm
Length > 5 µm
> 5:1 aspect ratio
Fibre = morphology (not mineralogy)
Does mineralogy matter with respect to fibre counting
No! A countable fibre is defined by morphology not mineralogy.

20. Copyright Resources Safety,Department of Mines and Petroleum
Controls
If you control the dust then you control fibre emission
RC dry drilling
RC wet drilling
Control dust = control fibre emission

21. Copyright Resources Safety,Department of Mines and Petroleum
Any questions?
For further information please contact:
Dave Fleming  