Threshold approach for acute fish toxicity testing

Topic: Fish acute toxicity

Test Method Number:

TM2005-05 (EU)

Short Name of TM:

THRESH FISH

Year received:

2005

Responsible Organisation:

EURL ECVAM - European Union

General Comments:

Method Description

The Threshold Approach for Acute Fish Toxicity testing is a tiered testing strategy and is based on the fact that the LC50/EC50 value of the most sensitive of the three test species (fish, algae and invertebrates) is commonly used for hazard and risk assessment and that fish is often not the most sensitive test species.
When fish acute toxicity data need to be generated, the fish limit test as described in OECD TG 203 / C.1 should be carried out at a threshold concentration using far less fish than the full LC50 test. The threshold concentration corresponds to the lowest LC50/EC50 derived from reliable acute invertebrate (e.g. Daphnia, OECD TG202) and algae (e.g. OECD TG 201) data. If no fish mortality is observed at the threshold concentration, it demonstrates that that the fish is not the most sensitive test species. No further testing is required and the TC value can be used as LC50 fish (LC50 fish is greater than TC with 99% of confidence). If mortality occurs at the threshold...

Track Approval Status

Submission
Validation
Peer-review
Recommendation
Regulatory acceptance/Standards

Submission

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Date	Stage	Comment	Documents/Links
Jan 2004	Not applicable

Validation

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Date	Stage	Comment	Documents/Links
Jan 2004	Finalised	EURL ECVAM and the former European Chemicals Bureau carried out a retrospective analysis of acute aquatic toxicity data from several databases and sectors, e.g. industrial chemicals, plant protection products and pharmaceuticals. The LC50/EC50 values reported for fish, algae and invertebrates showed that only in about 20% of the reported chemicals, fish is the most sensitive test species. Significant reduction in fish numbers could be achieved by following a stepwise approach.

Peer-review

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Date	Stage	Comment	Documents/Links
Jan 2006	Finalised	The ESAC peer reviewed the report "Proposal for a new testing strategy (Step-down approach) to reduce the use of fish in acute aquatic toxicity testing" summarising the outcome of the retrospective analysis several scenarios. Note: The ESAC recommended that the threshold approach should be used since it is based on existing OECD test guidelines. The ESAC statement refers to the Threshold Approach as "Upper Threshold Concentration (UTC) approach".	ESAC statement on the Threshold Approach for fish toxicity testing

Recommendation

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Date	Stage	Comment	Documents/Links
May 2010	Not applicable

Regulatory acceptance/Standards

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Date	Stage	Comment	Documents/Links
May 2010	Adopted/published	OECD Guidance Document 126 Short Guidance on the Threshold Approach for Acute Fish Toxicity was published in May 2010. The threshold approach has been incorporated into various testing strategies and guidance documents, e.g. the REACH guidance on information requirements and chemical safety assessment (Chapter R.7b: Endpoint specific guidance) and the OECD Fish Toxicity Testing Framework (OECD No 171, 2012). It is further mentioned as a preferred method for deriving data on acute fish toxicity in the biocidal products regulation (ECHA guidance on data requirements for biocidal products) and in the Commission regulation on data requirements for plant protection products (284/2013/EU).	OECD Guidance Document 126 Short Guidance on the Threshold Approach for Acute Fish Toxicity