VDI 3866 BLATT 4
Determination of asbestos in technical products - Phase contrast optical microscopy method
|Publication Date:||1 February 2002|
|ICS Code (Other standards related to air quality):||13.040.99|
Asbestos had many wide-ranging uses in the past, because of its many beneficial technical properties. The material was used in a highly concentrated form when heat insulation, fire prevention or noise insulation objectives were to be met, and no significant static requirements were made on the material (for example in the case of sprayed asbestos, seals, boards, strings). At lower contents, asbestos was used to reinforce materials, to improve fracture and bending characteristics (for example asbestos cement) or to increase elasticity and/or viscosity (for example of dyes, glues, seals, road pavings).
While the asbestos content in the former applications can be virtually 100%, in the latter products it is significantly lower and is usually between approximately 1% and 15 %. There are only a few known exceptions where the asbestos content is less than 1%. This is the case with some glues, sealing compounds and fillers.
Guideline VDI 3866 consists of the fundamental Part 1 on measurement planning and sampling and sample preparation  and four supplementary parts on determining asbestos with IR spectroscopy , X-ray diffactromety , phase-contrast microscopy and scanning electron microscopy .
All of the steps which are not method-specific and precede sample preparation and sample analysis are dealt with in Part 1.
Part 4 deals with the qualitative determination of asbestos, and estimation of asbestos content, by means of phase-contrast microscopy, a method which requires relatively little technical equipment. The main part of the guideline deals with routine determination of the three industrially relevant types of asbestos, chrysotile, crocidolite and amosite. The sequence of the rarely necessary analysis for all six types of asbestos (that is including the industrially unimportant asbestos types actinolite, anthophyllite and tremolite) is described in Annex A.
Even routine analysis requires knowledge of the entire guideline, including the annexes.