Omethoate chemical review

Omethoate was nominated for review in 1995 as part of the Existing Chemicals Review Program, which was established to systematically review a number of agvet chemicals that have been on the Australian market for some time. Omethoate was nominated because of concerns about toxicology, occupational health and safety, residues and trade. This action was based on advice from the Office of Chemical Safety that omethoate may pose an undue hazard to public health. The office further advised that an assessment of omethoate was required in conjunction with a concurrent review of dimethoate. This is because omethoate is the metabolite of dimethoate and the use of dimethoate on crops may lead to residues of omethoate in treated produce.

APVMA began its review of omethoate in 2004 and released the Dimethoate and omethoate review scope document, which outlined the information needed to conduct a comprehensive scientific assessment of omethoate and included a call for public submissions.

In 2011, the APVMA released Review of the mammalian toxicology and metabolism/toxicokinetics of omethoate. The assessment recommended:

• a change to the acceptable daily intake from 0.0003 to 0.0004 mg/kg bw
• the establishment of a new acute reference dose for omethoate of 0.003 mg/kg bw
• changes to the registration and safety directions for some home garden products
• a change in the maximum limit of the impurity O,O,S-TMP from 5 to 20 g/kg ai.

The APVMA has considered the Office of Chemical Safety recommendation and decided to maintain the impurity level at the current, more conservative, level of 5 g/kg.

In 2015 the APVMA published the Occupational health and safety assessment of omethoate which considered the risks to workers mixing or loading omethoate or re-entering crops treated with omethoate. The assessment recommended that the APVMA cannot be satisfied that the use of omethoate according to its existing label directions will not be a risk to workers and recommended:

• that the application of 800 g/L omethoate products by airblast equipment, equipment carried on the back of the user, or by aerial application to eucalypts should no longer be allowed
• amended and new safety directions including personal protection equipment
• new and amended re-entry periods for all crops.

In March 2016 the APVMA published the Omethoate: Residues and Dietary Risk Assessment Report which considered the residues and dietary risk arising from the treatment of food crops with omethoate. The assessment considered the available data and recommended that the APVMA could not be satisfied that any of the current uses of omethoate on food crops can be supported.

Assessments of the content of submissions in response to the Omethoate proposed regulatory decision report have been completed. The summary of these assessments is included in the final Omethoate regulatory decision report.

In May 2016 the Omethoate proposed regulatory decision report was published for a consultation period of three months. Submissions closed COB Thursday 4 August 2016.

The public, industry and interested parties were invited to provide written submissions on the proposed decisions for the reconsideration before the closing date of 4 August 2016. The APVMA has considered those comments when making the final decisions for the omethoate reconsideration.

The report took into consideration the recommendations in the technical assessment reports:

• Review of the mammalian toxicology and metabolism/toxicokinetics of omethoate
• Occupational health and safety assessment of omethoate
• Omethoate residues and dietary risk assessment report.

In May 2016 the Omethoate proposed regulatory decision report was published for a consultation period of three months. Submissions closed COB Thursday 4 August 2016.

A total of 12 submissions were received. The information in those submissions has been assessed by the APVMA and considered as part of the final decisions for the reconsideration of omethoate.

On 1 December 2016 the APVMA completed the reconsideration of approvals and registrations related to Omethoate. On 13 December 2016 the APVMA published the Omethoate regulatory decision report.

The APVMA has:

• affirmed all exisiting omethoate active ingredients approvals
• varied the instructions for the use of all products containing omethoate, as included in the relevant label particulars of label approvals
• affirmed the registrations of products and the varied label approvals.

The variations to the instructions for use of products containing omethoate have:

• removed all use patterns for the use of omethoate on food producing crops
• removed all use patterns for the use of omethoate on crops fed to food producing animals
• added re-entry periods and restraints on the methods of application of omethoate
• amended the safety directions for the use of omethoate.

This final decision has taken into account submissions received during the consultation period for the Omethoate proposed regulatory decision report.

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

The APVMA has decided to allow a 12 month period for the supply of omethoate products bearing previously approved versions of the label.

This period ends 1 December 2017.

After this period all product supplied should bear a currently approved label.