Methiocarb chemical review

In May 1995, methiocarb was nominated for review as part of the Existing Chemicals Review Program (ECRP) which was established to systematically review a number of Agvet chemicals which have been on the Australian market for some time. Methiocarb was nominated because of concerns over public health, occupational health and safety, exposure to methiocarb residues in food, and possible risks to Australian trade and the environment. There were also some adverse experience reports relating to domestic animals that were investigated by state departments at the time.

In 1995, the APVMA began a review of methiocarb because of concerns over public health, occupational health and safety, residues, and the environment

In May 2000, the National Drugs and Poisons Schedule Committee reconsidered the scheduling of methiocarb. The committee included methiocarb in schedule 7 (Dangerous Poison) of the Standard for the Uniform Scheduling of Medicines and Poisons (SUSMP). Formulations containing 20 per cent or less of methiocarb were placed in schedule 6 (Poison), and products containing 2 per cent or less remained in Schedule 5 (caution) of the SUSMP. Existing products had their labels amended to reflect the scheduling changes.

Component assessment reports on toxicology, occupational health and safety, environment and residues and trade were published in April 2005, along with the Preliminary Review Findings (PRF) (see Phase 6). These assessment reports were since updated to take into account the public comments on the PRF and the additional data received after the publication of the PRF report.

The 2005 toxicology and OHS assessments were updated by Office of Chemical Safety (OCS) and were published in June 2013. The OCS assessed toxicology data submitted to the review, together with information from its toxicological database and relevant published data. The 2013 assessment report recommended continued approval and registration of methiocarb, and revised the safety directions and first aid instructions for all methiocarb products.

In May 2017, the APVMA published a supplementary OHS report to update the 2013 OHS assessment. This report contains contemporary First Aid Instructions and Safety Directions for all methiocarb products.

In August 2018, the APVMA published the updated methiocarb toxicology report. This third toxicology report incorporates consideration of additional toxicological studies received after the publication of the 2013 toxicology report. As an outcome of this report the acute reference dose (ARfD) for methiocarb has been amended from 0.03 mg/kg bw to 0.005 mg/kg bw. Further, there have been no changes recommended to the approval status of the active constituent or to the current poisons schedule of methiocarb.

In August 2018, the APVMA published the updated methiocarb residues and trade report. This second residues report incorporates consideration of new information received after the publication of the 2005 PRF report. This report recommended that the label instructions be varied to delete, add or amend certain use patterns and amend withholding periods. It was recommended that the maximum residue limits (MRLs) standard of methiocarb be amended to reflect the findings of the residue assessments. Further, there have been no changes to the current residues definition of methiocarb and it remained appropriate for enforcement and dietary risks assessment purposes.

In August 2018, the APVMA published the updated methiocarb environmental report. This second environmental report incorporates consideration of new information received after the publication of the 2005 PRF report. This report recommended that label instructions be varied to minimise the risk to aquatic organisms resulting from runoff and harmful effects to birds and mammals.

In April 2005, the APVMA released the Methiocarb preliminary review findings report (PRF). The 2005 proposed review outcomes included deleting all uses on food crops. The 2005 assessment reports have since been updated to take into account the public comments on the PRF and the additional data received after the publication of the PRF report (see Phase 5).

On 27 August 2018, the methiocarb Proposed Regulatory Decisions report (PRD) was published for a consultation period of three months (see Phase 7).

After consideration of all data and assessments, the APVMA has concluded that the use of methiocarb according to its current instructions for use does not meet the safety criteria listed in sections 5A of the Agvet Code for continued registration and approval.

Therefore, the proposed regulatory decisions are that methiocarb active approvals and product registrations can continue provided the product labels are updated to delete, add or amend certain use patterns, amend safety directions and first aid instructions, add restraint statements and amend withholding periods. For more information on the proposed regulatory outcomes refer to methiocarb PRD.

On 27 August 2018, the methiocarb Proposed Regulatory Decisions report was published for a consultation period of three months.

The APVMA invites comment on the methiocarb Proposed Regulatory Decisions report from 27 August 2018 to 30 November 2018. Submissions close COB Friday 30 November 2018.

The APVMA will consider those comments when making the final decisions for the methiocarb review.

On 22 August 2019, the APVMA completed the reconsideration of registrations and approvals related to methiocarb.

Based on the findings of the regulatory decision report the APVMA has:

• affirmed methiocarb active constituent approvals as shown in the regulatory decision report
• varied the relevant particulars of product registrations and label approvals for methiocarb-containing products as shown in the regulatory decision report
• affirmed the product registrations and the varied label approvals as shown in the regulatory decision report.

The variations to the relevant particulars of label approvals for products containing methiocarb are shown in Appendix A of the regulatory decision report.

The final decision has taken in to account submissions received during the consultation period for methiocarb following the publication of the proposed regulatory decisions.

The APVMA has decided to allow a 12 month period for the supply of methiocarb products bearing the previously approved labels. After this period, all products supplied should bear the currently approved label.

The 12-month implementation period for the final regulatory decisions ended 22 August 2020.