The International Agency for Research on Cancer (IARC) has recently completed a reassessment of the herbicide 2,4-D confirming its 1987 classification of possibly carcinogenic to humans (2B).

2,4-D (2,4-Dichlorophenoxyacetic acid) is a common chlorophenoxy herbicide used for the post-emergent control of broadleaf weeds. It is also used as a plant growth regulator for some fruit crops. There are around 250 products containing 2,4-D registered for use in Australia. 2,4-D has been registered for use for over 50 years.

APVMA’s current review of 2,4-D

All 2,4-D products currently registered for use in Australia have been through a robust chemical risk assessment process. The APVMA began a review of 2,4-D in 2003 due to concerns about its potential human toxicity (including carcinogenicity), occupational risks to people, risks to the environment and dietary risks due to residues in food. The review has examined all new and previously assessed scientific information. We expect the 2,4-D review findings and proposed recommendations to be available for public comment in the third quarter, 2018. Information about the review can be found on APVMA’s website.

Part 1 of the 2,4-D review involving high volatile ester (HVE) forms of 2,4-D has already been completed. Priority was given to the assessment of HVEs due to numerous reports of off-site plant deaths caused by 2,4-D HVE vapour movement. Regulatory action was taken cancelling most products containing 2,4-D HVEs.

Assessment of the other forms of 2,4-D is currently underway as Part 2 of the review and will include toxicity, occupational health and safety, environmental and residues assessments. The assessment reports will be published on the APVMA’s website when each report is finalised.

Assessment of 2,4-D products will also consider risks associated with dioxins impurities. Low levels of dioxins may be produced during the manufacturing process of 2,4-D. The assessment of 2,4-D will consider risks to workers and the public from exposure to dioxin contaminants in the 2,4-D products.

Revised timeline

Chemical Reviews (reconsiderations) are dynamic and our work plans must be flexible to consider:

  • new scientific information
  • our response to emerging issues that may need regulatory action to address.

The 2,4-D work plan has been reviewed and updated in line with the legislation and associated regulations. We have received additional assessment data from approval and registration holders since the review started on 1 July 2015, so the modular assessment levels in this work plan have been adjusted.

The 2,4-D review scope and work plan has been adjusted to include a toxicology level 3.2 assessment (previously a level 3.3) and environment level 7.1 assessment (previously a level 7.3). The recalculated timeframe for the 2,4-D review is 43 months. We expect the review findings and proposed recommendations to be available for public comment in the third quarter 2018.

Using 2,4-D products

Based on current risk assessments the label instructions on all registered 2,4-D products—when followed—provides adequate protection for users.

People should follow the use and safety instructions on all chemical product labels as these are designed to reduce human exposure to the chemical product. If the label has been removed or damaged, you can search the APVMA’s chemical database to find the safety information about registered products and permits.

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