4TH INTL CONFERENCE OF MEDICHEM; ACGIH, AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS; CANTOX; CHLORINE INST; EEC, EUROPEAN ECONOMIC COMMUNITY; FDA, FOOD AND DRUG ADMINISTRATION; GOODRICH; ICI; MONTEDISON; OSHA, OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION; RHONE POULENC; SOLVAY; TOXICOLOGY FORUM DC SEPTEMBER 1993; UK HSE