4.2 Example—outline of bulk sampling qa/qc procedure

Bulk sample analysis procedures are defined in the NIOSH method for PLM and the NIOSH 7402 method for ТЕМ. Because bulk sample analysis is done by an independent laboratory off-site, this QA/QC document will not address bulk sampling as a field-verified procedure. The NVLAP is currently used to ascertain laboratory effectiveness. The contractor must provide proof that NVLAP certification is current for the laboratory des­ignated to receive both the initial bulk samples and the 10% bulk sample duplicates.

The optical properties and ID of fibers are as follows:

• Determine 13 specific items for asbestos.

• ID other fibers with some optical data.

• ID matrix components.

In addition record

• Special procedures or solvents

• Sampling of layers

• Deviations from EPA test procedure

The 10% bulk sample duplicates are provided by physically dividing 10% of the sam­ples collected. This division should occur concurrently with the collection of field samples. The rationale for splitting the samples at a time and location removed from the field col­lection site must be provided.

All field collection procedures, sample labeling, and transport and disposal procedures must be addressed in the QA/QC document. Provide the rationale for the classification and remediation of errors. The following is a sample of error classification:

Major Error

• False positive

• False negative (asbestos actually >1%)

• Incorrect asbestos type classification

• Analysis quantification in error by 25%

Minor Error

• Incorrect ID of tremolite or actinolite as another type of asbestos

• False negative (asbestos actually >1% or trace)

• Analysis quantification in error by 15%

• Incomplete lab data sheets (repeated omissions may equal major error)

Corrective Steps—Major Errors

• Take immediate action.

• Review documents for transcription errors.

• Review sample, especially matrix description.

• Reanalyze sample; submit to other labs for analysis.

• Check environment for contamination and out of calibration equipment.

• For misidentification of asbestos species review literature and reference samples.

Corrective Steps—Minor Errors

• One to two weeks or after monthly summaries

• Steps 1 through 4 above.

• Review to determine if error is systematic estimation bias, then retrain on esti­ mation techniques and/or sample preparation techniques.

• Completed data sheets are required; frequent omissions should be considered a major error.

• Review sampling and stereomicroscope sample preparation procedures.

• To recalibrate estimation techniques, reanalyze known samples; review literature on estimation training.

• Review; retrain on reference samples, especially in problem matrix mixtures. Review specific problems like tremolite or crocidolite samples.

• Review lab's special sample preparations for Vinyl Asbestos Tile (VAT) or tar matrix materials. Practice on known materials including blanks.