Evaluation of the use of low flow passive sampling technique in offset printing plants.

Objectives: The aim of this study was to evaluate the suitability and applicability of low-flow passive tubes for sampling of organic solvents in occupational environment.

Materials And Methods: Laboratory and field studies were conducted to continue the evaluation of low-flow diffusive sampling combined with thermal desorption and gas chromatographic/mass spectrometric analysis in occupational hygiene surveys. Passive sampler tubes with Tenax GR adsorbent were employed to assess exposures to organic solvents in 10 small sheet-fed offset printing plants in Finland. The retention of the solvent compounds in the samplers was investigated using laboratory chamber studies. Active sampling with activated carbon tubes served as the control method.

Results: The laboratory tests showed that passive tubes had good retention, stability and reproducibility for the solvent compounds. Parallel passive and active sampling in both breathing zone and area monitoring in the printing plants yielded similar measurements though passive sampling tended to give slightly higher concentrations (by 5 to 12%). The suitability of passive sampling to be done by workers was also confirmed. The study also shows that exposure to organic solvents can be effectively reduced by the use of vegetable oil-based cleaning fluids. Especially, since ventilation and other protective measures are often inadequate in small facilities, the use of toxic cleaning solutions should be avoided.

Conclusions: Passive sampling tubes with capillary orifice analyzed with thermal desorption GC-MS are well suited for measuring occupational solvent exposure. Method is well suited for sampling done by workers.