Bromsalans chemical review

The bromsalans have been used as flukicides in commercially available mixtures of dibromsalan and tribromsalan. Hilomid contains a mixture of dibromsalan and tribromsalan in a 1:1 ratio; diaphene contains a 1:3 ratio.

No products containing the bromsalans are currently registered for use in Australia.

In 1989, the National Health and Medical Research Council (NHMRC) began a reconsideration of the bromsalans, in particular diaphene, based on concerns about a lack of toxicological and residues data. As part of the reconsideration, the NHMRC requested more toxicological data from registrants to support the continued registration and use of their bromsalans products.

The registrants failed to provide the additional data. In March 1993, the NHMRC advised the Australian Agricultural and Veterinary Chemicals Council (AAVCC) of its concerns and recommended withdrawing the maximum residue limits (MRLS) for the bromsalans and placing them in Appendix M of the Standard for the Uniform Scheduling of Drugs and Poisons (SUSDP). The appendix applied to ‘substances for which registration under agricultural and veterinary chemicals legislation cannot be supported by scheduling until further toxicological information becomes available’.

In January 1994, the APVMA began a special review of bromsalans to formally consolidate the previous regulatory action by the AAVCC and NHMRC.

The APVMA completed the special review of bromsalans in September 1994 but did not publish a final report due to the small number of registrants involved.

The APVMA withdrew the MRLs for bromsalans and cancelled the registration of all related products, with effect from 1 November 1994. The APVMA found that there were insufficient toxicological and residues data to support the continued registration and use of bromsalans and, in particular, the use of diaphene.

In its report, the APVMA recommended:

• cancelling the active constituent approval, with effect from 1 November 1994
• cancelling the MRLs for bromsalans (tribromsalan and dibromsalan), with effect from 1 November 1994
• cancelling all registrations and relevant approvals of products containing bromsalans, with effect from 1 November 1994.

Contac the APVMA for copies of the APVMA Gazette notice: Cancellation of registration for agricultural products.