Aquatic Life Reference Values (ALRVs)

Health Canada's Pest Management Regulatory Agency (PMRA) has established surface water Aquatic Life Reference Values (ALRVs) for pesticides currently registered for use in Canada.

On this page:

• What are ALRVs
• How ALRVs are used
• ALRV data

What are ALRVs

The PMRA has established Aquatic Life Reference Values (ALRVs) for over 280 pesticides. ALRVs are pesticide concentrations in surface water below which risks to aquatic life are not expected. PMRA's ALRVs are thresholds for individual pesticides, based on toxicity values for aquatic species, with the goal of protecting the environment. Other federal and provincial departments may also develop thresholds or use other reference values to protect aquatic life. These are developed with different risk management goals in mind using varying methods. As a result, these thresholds may not be equivalent to PMRA's ALRVs.

The PMRA follows internationally accepted methods to assess both long-term (chronic) and short-term (acute) risks to fish and invertebrates. The risk to aquatic vascular and non-vascular plants is also assessed using internationally accepted methods. For a given pesticide, there are up to six ALRVs, depending on the organism group and exposure duration, that form the basis of a pesticide risk assessment:

• acute fish and chronic fish
• acute invertebrates and chronic invertebrates
• aquatic vascular plants
• aquatic non-vascular plants (algae)

These values are found in the regulatory decision documents published by PMRA for every pesticide evaluation or re-evaluation; new or updated ALRVs are established upon publication of a final decision. The process for establishing PMRA's ALRVs is similar to that used by the United States Environmental Protection Agency (USEPA) to establish the USEPA Aquatic Life Benchmarks (USEPA ALBs). If PMRA does not have an ALRV, the USEPA ALB is used. Note that there will be a delay between the publication of PMRA final decisions or USEPA ALBs and updates to the ALRV table below.

Short-term (acute) ALRVs

• These are indicative of the possible impacts to the aquatic environment that can come from short-term exposure to high concentrations of a pesticide. Aquatic organisms exposed to concentrations of the pesticide at or below the acute ALRV are unlikely to experience severe adverse effects such as mortality.

Long-term (chronic) ALRVs

• These are indicative of the possible impacts to the aquatic environment that can come from long-term exposure to pesticide concentrations. Aquatic organisms are unlikely to experience adverse effects when surface water concentrations of a pesticide are at or below the chronic ALRV. Small exceedances of the chronic value for short periods of time are not expected to cause harm.

How ALRVs are used

Comparing the measured concentration of a pesticide in water with an ALRV can be helpful in interpreting monitoring data. It can also provide useful information for identifying and prioritizing sites and/or pesticides that may require further investigation.

If concentrations of pesticides in water are below the ALRV, they are not expected to pose risks to freshwater aquatic life. If the concentrations of pesticides in water are equal to or higher than the ALRV, risks to aquatic life may occur, and additional steps may be taken.

Additional actions that PMRA may take when ALRVs are exceeded could include:

• examining information about the use of the pesticide and the current risk management measures in place
• collecting additional site-specific data to further identify the risk
• conducting a re-evaluation or special review that could result in new risk mitigation measures

ALRV data

The table below lists ALRVs for pesticides that are registered for use in Canada; ALRVs for pesticides that have been cancelled or discontinued are included in the table up to five years after the last date of permissible use. These values are updated annually based on the most recent PMRA decision documents.

The table was updated May 13, 2024. New and updated ALRVs are shown in bold text. A summary of these changes is provided in the Record of Data Changes.

The table and footnotes can also be viewed through the downloadable CSV files.

Download table as a CSV

Download footnotes as a CSV

ALRV table information

Empty cells indicate that acceptable aquatic toxicity values are not available.

ALRVs preceded by ">" were derived from a "greater-than" value and may overestimate toxicity. ALRVs preceded by "<" were derived from a "less-than" value and may underestimate toxicity.

Abbreviations:

LC₅₀

50 percent lethal concentration

LD₅₀

50 percent lethal dose

EC₅₀

50 percent effect concentration

IC₅₀

50 percent inhibition concentration

NOAEC

no observed adverse effects concentration

NOEL

no observed effect level

NOEC

no observed effect concentration

HC₅

5 percent hazard concentration

UF

uncertainty factor

µg/L

microgram per liter

For additional information on the abbreviated terms visit the glossary of terms for environmental water monitoring for pesticides

Related links

• PMRA Guidance Document, A Framework for Risk Assessment and Risk Management of Pest Control Products
• Decisions and updates
• Aquatic Life Benchmarks and Ecological Risk Assessments for Registered Pesticides | US EPA
• Human Health Reference Values (HHRVs)
• Glossary of terms for environmental water monitoring for pesticides