1. Centre for Workplace Health, Health & Safety Laboratory Harpur Hill Buxton SK17 9JN U.K
2. Procter & Gamble Rusham Park, Whitehall Ln Egham Surrey TW20 9NW U.K
3. Health & Safety Executive Redgrave Court, Merton Road Bootle Merseyside L20 7HS U.K
4. Leeds General Infirmary Great Geore St Leeds West Yorkshire LSI 3EX U.K