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New Worksafe Australia Standard
by Fred Salome
Control of Inorganic Lead at Work
Worksafe
Australia last October published its standard The Control of Inorganic Lead at Work with
an accompanying National Code of Practice for the Control and Safe Use of lnorganic Lead
at Work
Although published in October 1994 the Standard was substantially
completed in 1991. Final ratification was delayed due to action in the Federal Court on
the question of sex discrimination in setting differing requirements for women who are of
reproductive capacity, pregnant or breast feeding than for others.
This matter was resolved in November 1993 when the Court ruled that
Worksafe had a duty to clearly indicate the health affects for all workers who may
be exposed to lead and to set appropriate health and safety standards.
Because of this delay the standard is out of date on the permissible
occupational exposure level of lead-in-air, and the definition of lead paint.
Atmospheric Lead Exposure Levels
The standard sets the maximum level of lead in air permitted to he
inhaled by workers over a normal 8-hour working day at the current exposure standard of
150 µg/M³. This is the figure listed in "Exposure Standards for Atmospheric
Contaminants in the Occupational Environment' last reviewed in 1991.
The standard requires medical removal from lead-risk jobs if the PbB
exceeds 50 µg/dL, and for all pregnant or breast-feeding employees regardless of PbB.
It defines a lead-risk job as one that might cause the PbB to rise
above 30 µg/dL (less for some women). The Code of Practice gives a correlation between
PbB's of 30 µg/dL and exposure to lead-in-air concentrations of 30 µg/M³.
No direct linear correlation exists between lead exposures and PbB. The
actual compound of lead, its bioavailability and particle size and the exposed person's
metabolic system impact on this relationship.
Nevertheless it is clear that workers inhaling lead levels approaching the permissible
exposure
standard of 150 µg/M³ may readily end up with PbB's well in excess of the limits set for medical removal. According
to US OSHA legislation the permitted exposure level (PEL) is 50 µg/M³, one third of the
Australian limit. US law (under the current Title X legislation) also defines an Action
Level (intended to he a warning signal to employers that a job is approaching the PEL) of
30 µg/M³.
At the Action Level monitoring of lead-in-air concentrations, employee
training and medical surveillance of employees (ie. monitoring PbB's) become compulsory.
The US Action Level is equal to the Australian figure defining a lead-risk job.
An exposure standard of 150 µg/M³ is inconsistent with the objective
of preventing elevated blood lead levels in workers, and we urge Worksafe to revise the
exposure standard for lead downwards to a figure of 50 µg/M³ at the earliest
opportunity.
Definition of Lead Paint
The standard contains a schedule of "lead processes" which
includes "Machine sanding or buffing of paint (with more) than 1% of lead". Because
of this, the same figure of 1% lead content has been included in the new draft Standard Guide
to lead paint management – Industrial Applications.
However sanding or buffing paint is not the same as removing paint
by abrasive blast cleaning or power grinding. Abrasive blast cleaning is the commonly
preferred method of removing lead paint from steel. Lead-in-air levels of 50 µg/M³ can
be exceeded when blast-cleaning paint with 0.06% lead.
US studies have shown that lead paint removal workers recorded higher
PbB's (and lower life expectancies) than general lead-industry workers. Lead paint removal
has been identified as a major cause of lead poisoning among workers and OSHA regards a
lead-containing paint to be one containing any amount of lead.
In 1991, the Australian NH&MRC limit for lead in paint was 0.5% for
domestic use. This figure was lowered to 0.25% in March 1992 and in 1997 will be further
lowered to 0.1%.
We urge Worksafe to amend its standard to include the removal by abrasive blast
cleaning, power tool or hand tool cleaning of paint containing greater than 300 ppm
(0.03%) by dry weight of lead.
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