Document ID: chunk:federal_register_of_legislation:F2016L00417:body:0:p14
Version: federal_register_of_legislation:F2016L00417
Segment Type: other
Provision Reference: 
Character Range: 34580–37452

for medical examinations and biological monitoring of workers carrying out a lead process, and
    * assessing each lead process to determine if the lead process is lead risk work, i.e. if the work is likely to cause a worker's blood lead level to be more than 10 micrograms per decilitre (for a female of reproductive capacity) or 30 micrograms per decilitre (for all other cases).

Assessing the risks from dust exposure
There are a number of factors that affect the degree of risk associated with dust produced in abrasive blasting activities. These factors include:
    * the concentration of airborne dust in the breathing zone of the worker
    * the size of the dust particles generated (whether dust particles are inhalable or respirable)
    * the duration of exposure, and
    * the type of dust and its biological effect
You should also identify situations where dust could spread to other workplaces or the environment.

Control of dust

Using a less hazardous abrasive material
Before purchasing any abrasive blasting mediums, you should look at the label and SDS to check the concentration of impurities and whether its use is prohibited or restricted under the WHS Regulations. Where a material is prohibited from use, your supplier may be able to advise alternative abrasive blasting medium (see Appendix A).
It is important to select an abrasive blasting medium with qualities that will generate minimum dust levels. Metallic abrasives have proven characteristics that resist shattering on impact, which is the major cause of the dust produced during blasting. Environmentally clean and recyclable abrasives, such as chilled iron grit or cast steel grit, should be used where reasonably practicable.

Using a less hazardous surface preparation method
The selection of methods of surface preparation can also affect the amount of dust in the air.

Wet abrasive blasting
A standard blast machine and compressed air are used to propel the abrasive with just enough water added to suppress the dust. Inhibitors are sometimes added to the water to minimise flash rusting. For effective dust suppression, the water should be added before the abrasive leaves the nozzle. The use of inhibitors such as chromate, nitrate or nitrite must comply with the restrictions on use  in Table 10.3 of Schedule 10 of the WHS Regulations.

Water jetting (high and ultra high pressure)
High pressure water jetting is an alternative method to abrasive blasting. For further information
on high pressure water jetting you should refer to AS/NZS 4233.1 High pressure water (hydro) jetting systems Part 1:– Guidelines for safe operation and maintenance and AS/NZS 4233.2: High pressure water (hydro) jetting systems Part 2:- Construction and performance.

Centrifugal wheel blasting
Centrifugal wheel blasting involves a rotating wheel assembly, either air or electrically driven,