A One Insulation Limited

MDHS100 Type 2 Asbestos Survey

Standard sampling, identification and assessment survey (sampling survey)

The purpose and procedures used in this survey are the same as for Type 1, except that representative samples are collected and analysed for the
presence of asbestos. Samples from each type of suspect asbestos cement material found are collected and analysed to confirm or refute the
surveyor's judgement. If the material sampled is found to contain asbestos, other similar homogeneous materials used in the same way in the
building can be strongly presumed to contain asbestos. Less homogeneous materials will require a greater number of samples. The number should
be sufficient for the surveyor to make an assessment of whether asbestos is or is not present.

Sampling may take place simultaneously with the survey, or as in the case of some larger surveys, can be carried out as a separate exercise, after the
Type 1 survey is complete.

Bulk sampling may be carried out simultaneously with the survey or carried out later as a separate sampling exercise. Often for small surveys it is
convenient to take samples when the building is empty. After a visual examination to assess any apparent areas of different material, samples of
about 3-5 square cm area and through the entire depth of the asbestos cement material should normally be taken with the aim of collecting one or
more samples which are representative of the whole material. Sampling should not be carried out where there is an electrical hazard or if it will
damage the critical integrity of a roof, gutter, or a pipe.

The sampling strategy will be based on the types of asbestos cement materials present, and for larger premises there is often an advantage in
sampling after a Type 1 survey has been completed, so the numbers and locations of the samples required can be specified. In general, for
homogeneous manufactured products containing asbestos, it can be assumed that the asbestos is uniformly distributed throughout the material, and
one or two samples will suffice, eg boards, sheets, cement pipes, textiles, ropes, friction products, plastics and vinyls, mastics, sealant, bitumen
roofing felt and gaskets. Insulation materials are generally less homogeneous as they were applied on site and their composition depended on the
availability of supply. Subsequent repairs and patching may add to this variability and increase the number of samples required.

In addition, substantial over-spray contamination and debris may have been produced. Often a single sample may be all that is required to confirm the
suspicion that a homogeneous material is asbestos and to make a presumption that it applies to other material of the same type. However, for
non-homogeneous materials and for some presumed non-asbestos materials, additional sampling may often be needed, to reduce the possibility of
false negatives which may lead to uncontrolled exposures. The following sample numbers are suggested, but may be adapted depending on the site
and the circumstances prevailing.