Sampling of metals can be done in the inhalable fraction (E-dust) as well as in the alveolar fraction (A-dust). The appropriate sampling depends on the fraction in which the occupational exposure limit is to be checked. 

Sampling

The following sampling systems are available at the GSA for sampling E-dust:

  • SG10-2 with GSP3.5 ( personal sampling)   
  • SG5100ex with GSP3.5 (personal sampling)   
  • PM4-2 with total dust head (stationary sampling)
  • VC25-2 with total dust head (stationary sampling) 

 
The following sampling systems are available at the GSA for sampling A-dust:

  • SG10-2 with FSP-10 (personal sampling)   
  • PM4-2 with fine dust head (stationary sampling)
  • VC25-2 with fine dust head (stationary sampling)

The sampling volume for the measurement depends on the occupational exposure limit to be checked.

As an example, the following heavy metals can be analysed from one sample: Arsenic, cadmium, cobalt, chromium, copper, mercury, nickel, lead, antimony, tin, thallium, zinc.
 

Analysis

Sample preparation is carried out according to DIN 16711-1 (04/2014) “Determination of metal – microwave digestion”. The sample is homogenised and processed by means of total digestion in the microwave in high-pressure vessels.

Subsequently, the quantitative determination is carried out according to DIN EN ISO 17294-2 (01/2017) “Determination of 62 elements by ICP-MS” mass spectrometer with inductively coupled plasma. Rhodium and rhenium are used as internal standards, the calibration of the ICP-MS is carried out in a simple linear way by means of a multi-element standard. 
 

Examples for assessment criteria of carcinogenic metals TRGS 910

Substance  Assessment criterion 
Arsenic compounds, classified as carc. 1A, 

carc. 1B 

TC 8,3 μg/m³ (E) 

AC 0,83 μg/m³ (E) 

Cadmium and inorganic cadmium compounds, classified as carc. 1A, carc. 1B  TC 1,0 μg/m³ (E) 

AC 0,16 μg/m³ (A) 

Cobalt and cobalt compounds, classified as 

carc. 1A, carc. 1B  

TC 5,0 μg/m³ (A) 

AC 0,5 μg/m³ (A) 

The occupational exposure limit values for most metals can be found in TRGS 900.

For example, manganese and its inorganic compounds have an occupational exposure limit value of 0.02 mg/m³ in the alveolar fraction (A-dust) and 0.2 mg/m³ in the inhalable fraction (E-dust).

Beryllium and beryllium compounds have an occupational exposure limit value of 0.06 µg/m³ in the alveolar fraction (A-dust) and 0.16 µg/m³ in the inhalable fraction (E-dust).

Stationary measurement of E-dust and A-dust for metals
Personal E-dust measurement for metals