Determination of talc

According to TRGS 900, there is no specific occupational exposure limit for talc.

Talc falls under the scope of the general dust limit values (ASGW). 

For the assessment of the occurring dust concentrations in the air of the working area, the inhalable (E-dust fraction) and the alveolar dust fraction (A-dust fraction) of the ASGW according to TRGS 402 have to be determined and evaluated as a rule. The higher substance index is to be used for the workplace assessment.
The former occupational exposure limit for talc, according TRGS 900 (from 2004), was 2 mg/m³ in the alveolar fraction (A-dust).
 

Sampling

Sampling is carried out as described for the gravimetric determination of the alveolar dust fraction (A-dust) according to IFA 6068 or for the gravimetric determination of the inhalable dust fraction (E-dust) according to IFA 7284.

If you are interested in the pure talc content, we recommend the analysis in the FTIR spectrometer.

Analysis with FTIR spectrometer

• FTIR spectrometer Spectrum TWO and Spectrum 100 by Perkin Elmer

Preparation of sampling

The collected cellulose nitrate filter is incinerated with the aid of a cold ashing device under oxygen supply. In the cold ashing device, at 60 °C, the filter substrate as well as interfering organic components of the dust sample are oxidised away. The resulting residue is then homogenised with potassium bromide and pressed into a compact.

Evaluation

An absorption spectrum in the range of 4000 cm^-1 bis 400 cm^-1 is recorded from this compact with the aid of the FTIR spectrometer.

At 3677 cm^-1 talc has an unusually narrow but characteristic band which is used for quantitative detection.

The detection limit here is 100 µg absolute.