Seeks comments on proposals for new maximum exposure limits (MELs) for refractory ceramic fibres and subtilisins. Explains the current system of exposure limits, how occupational exposure limits (OELs) are set. Describes the proposed new system of occupational exposure limits, regulatory impact/ cost benefit assessments, proposals for changes to the maximum exposure limits. Includes a response form. In the light of comments received, the Health and Safety Commission will approve the new limits as appropriate; the agreed limits will then come into force on the publication of the 2004 edition of The Health and Safety Executive publication 'EH 40 - Occupational exposure limits.'