Posted By Darren J Fraser Hi All I could find was this on HSE website search (updated 05.05.06)if any help, alternatively ring the HSE Infoline on 0845 345 0055 Under the COSHH Regulations there is a Maximum Exposure Limit (MEL) for respirable crystalline silica (RCS) of 0.3 mg.m-3 (8-hour time weighted average [TWA]). Current evidence indicates that if workers are exposed regularly to 0.3 mg.m-3 there is a much higher risk of lung damage than had been previously thought. The legal requirement for substances with MELs is to control exposure as far below the MEL as is reasonably practicable. In the past some industry sectors had difficulty in controlling exposure to RCS below 0.3 mg.m-3. HSE believes it should now be reasonably practicable for all industry sectors to control RCS to 0.1 mg.m-3 (8-hour TWA). The purpose of this CHAN is to raise awareness among employers and workers about the new evidence on RCS and to advise that employers should aim to control exposures to 0.1 mg.m-3 (8-hour TWA) or below. HSE is not proposing a formal change to the MEL because a new system of Occupational Exposure Limits (OELs) is planned to be in place by the end of 2004 which is likely to overtake any new MEL developments. HSE's intention is to consult on a more stringent OEL for RCS when the new OEL system comes into force. Regards Darren