Faas

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F. _ RECOMMENDATIONS
(a) GENERAL

1. HOW TO SAMPLE :

As with the counting technique, a detailed protocol describing
the strategy, sampling rate, size of filter, sampling time, etc. is needed.
Any legislation involving a dust standard should spell out in absolute detail
the methods to be used, frequency of sampling, duration, the expected tolerance
on results and how results will be interpreted. This will ensure that the
effort is placed on control and not in endless confrontations between industry

and inspection authorities.

2. WHERE TO COLLECT SAMPLES

The decision on where to take samples will depend on the plant

in question but should include all locations where employees work. It is

useful to have some fixed sampling locations which will indicate more accurately
the changes in the general environmental situation. Personal samples are
essential to identify locations or jobs involving elevated exposures.

3F WHEN & HOW LONG TO SAMPLE

‘The tendency should be towards longer sampling periods, insofar
as the concentration permits. A statistically sound sampling program should
be established to provide information on the actual airborne fibre concen-
trations within a plant. Such a program would provide for a minimum number
of samples necessary to take account of operational, daily, weekly and
seasonal variations of dust concentrations. For some plants this approach
may involve many measurements and have practical limitations. Nevertheless,
the adoption of such an approach would permit the company to know how sure
it could be that the measurements really were reflecting the true environmental
conditions. A few spot measurements which are ideal when seeking dust leaks
may not give adequate information on the true exposure of the workers and
hence in future years compensation claims may still occur because the
environmental surveys were inadequate to determine whether controls were

effective.