Dinoseb Added to CEPA Schedule 1

Summary#

This is a proposed order to add phenol, 2-(1-methylpropyl)-4,6-dinitro- (dinoseb) to Schedule 1 of the Canadian Environmental Protection Act, 1999. The notice was published on October 1, 2022 and the public has 60 days to comment. Adding the substance to Schedule 1 would allow the government to develop rules or other actions to manage its environmental risks, but it would not itself create new legal obligations.

What it does#

• Adds dinoseb (the full chemical name above) to the List of toxic substances in Schedule 1 of the Canadian Environmental Protection Act, 1999.
• Gives the ministers responsible for the Act the authority to propose risk-management actions (for example, regulations or an environmental performance agreement). The Order itself does not impose new controls.
• Follows a screening assessment that found dinoseb meets the ecological test for being “toxic” because it can harm aquatic life when released from industrial activities.
• Opens a public comment period (published October 1, 2022; comments accepted for 60 days).

Who's affected#

• Companies involved in the industrial production or processing that can release dinoseb, notably facilities that make styrene monomer and small industrial users that handle dinoseb acetate.
• Importers of dinoseb or dinoseb salts.
• Rivers, lakes and the aquatic animals and plants near sites that release industrial wastewater containing dinoseb.
• The general public and consumers are unlikely to be affected now because dinoseb is not used in consumer products and its herbicide uses were discontinued (registration was suspended in 1990 and uses stopped by December 31, 2001).
• Indigenous groups and provincial/territorial governments, who may be consulted further if specific risk-management measures are developed.

Why it matters#

• The government’s assessment found dinoseb can persist in water and is toxic to fish and other aquatic life at concentrations that could occur in some industrial release scenarios. That creates an environmental risk near release points.
• Adding it to Schedule 1 is the step that lets officials propose concrete measures to reduce releases and protect ecosystems. It could lead to rules, pollution controls, or agreements with industry.
• The order itself does not change any rules immediately. But it starts the process that could lead to limits, monitoring, or cleaner practices around facilities that handle or release dinoseb.