Using solvents in printing results in exposing Operatives to hazardous vapours.
The Control of Substances Hazardous to Health Regulations (1994) (COSHH) includes Regulation 7 that requires LEV’s ( Local Extract Ventilation) to be installed to control the risk. Regulation 9 requires that the control measures be assessed every 14 months maximum to ensure that they are operating correctly and efficiently to minimise the exposure risk.
EPM carry out the assessment in two parts:-
- mechanical inspection
- monitoring Operator exposure levels
Low level extraction (LEV’s) is necessary in Ink Stores, etc to prevent build up of solvent vapours to dangerous levels. However, the press dryers, recirculation and supply ducts are also classed as LEV’s because they are controlling solvent levels. The mechanical inspection involves monitoring the airflows, checking for correct fan operation, air leaks in ducts and flexible connections, etc. Flexible ducts on inter-colour dryers are particularly vulnerable to damage and are important that they are airtight. Dryers should also be checked for correct air balance to ensure good suction with no overspill of solvent vapour into the workspace.
Operator exposure concentrations are defined in the HSE document EH40 for different solvent levels. In a printing environment, Operatives most at risk are identified and monitored over a working shift (normally 8 hours) carrying out their normal tasks. Exposure is assessed using sampling equipment which captures the airborne solvent during the working period. The solvents are quantified by analysis and compared to the levels defined in EH40.
Monitoring Operator Exposure
Using a sampling pump and absorption tube
Checking for correct suction at a Big Wicket Machine