Herbicide ban

The herbicide known as 2,4,5-T was used across Ontario from the 1950s through the 1970s for weed and bush control.

It was used by government ministries and agencies and by individuals, companies and municipalities.

Ontario banned 2,4,5-T in 1980 due to possible human health impacts. It was deregistered by the federal government in 1985.

If you’ve been exposed

If you have health concerns related to possible 2,4,5-T exposure see your doctor.

If you are concerned about potential past workplace exposure to 2,4,5-T, contact the:

Workplace Safety and Insurance Board (WSIB)


Report on 2,4,5-T

In 2011, the Ontario government established an independent fact-finding panel to look at:

  • when, where and how 2,4,5-T was used in the province for weed or brush control by government ministries and agencies. The panel also examined whether exposure to provincial workers and bystanders may have potential health impacts
  • how 2,4,5-T was prepared, stored and applied
  • the occupational health and safety laws and workplace practices in place at the time

You can read the full report online or request a paper copy from:


Toll-free: 1-800-668-9938

TTY: 1-800-268-7095

Download the report on herbicide 2,4,5-T

Herbicide safety in Ontario

Since 2,4,5-T was banned, the government has continuously improved the way herbicides and other pesticides are used in Ontario, including strict regulations and approvals on how they are:

  • sold
  • transported
  • used
  • stored
  • disposed