In November 1991 the National Health and Medical Research Council (NHMRC) began a reconsideration of chloroxuron because of concerns over the lack of toxicological data. At that time, the registrant advised the NHMRC that it had voluntarily ceased production in 1990 and would discontinue the registrations of products containing chloroxuron when existing stocks had been exhausted. A one-year period was requested to phase out existing retail stocks.
In 1993 the NHMRC recommended that chloroxuron be placed in Appendix M of the Standard for the Uniform Scheduling of Drugs and Poisons; this appendix was for ‘substances for which registration under agricultural and veterinary chemicals legislation cannot be supported by scheduling until further toxicological information becomes available’.
In August 1994 the APVMA (then known as the NRA) was advised of concerns over the gaps in the chloroxuron toxicological database, and began a special review of chloroxuron to formally consolidate the previous regulatory action taken by the NHMRC.