4,4'-Isopropylidenediphenol, ethoxylated

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Study was conducted by a GLP accredited laboratory using OECD Testing Guideline 209. Read across is considered justified within this class of substance i.e. from BPA 6.3EO to BPA 1-4.5EO. The two substances have common precursors and breakdown products, as well as common constituents. They are also of the same chemical class. Furthermore, the BPA 6.3EO can be expected to breakdown to BPA (n)EO with values of 'n' lower than 6.3 when in the bacterial environment of this test system.

Reason / purpose for cross-reference:

read-across source

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 230 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

EC50 = 10 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test substance on the respiration rate of domestic activated sludge was investigated. The 30 minute EC20 of the test substance was found to be 230 mg/l.

Executive summary:

The toxicity of the test substance to microorganisms was determined in accordance with the OECD Guideline for Testing of Chemicals 209. The study investigated the effect of the test substance on the respiration rate of domestic activated sludge. The activated sludge was exposed to the test substance at concentrations of 11.2, 100, 500 and 1000 mg/L for 30 minutes. The EC₂₀ of the test substance was 230 mg/L based on respiration rate.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the section 'Justification for type of information' above.

Description of key information

A read-across study on BPA 6.3EO gave a 30 minute EC20 of 230 mg/L based on respiration inhibition of activated sludge. A no-effect concentration was not reported. 

Key value for chemical safety assessment

EC50 for microorganisms:

230 mg/L

Additional information

A read-across study was conducted to assess the toxicity of the test substance to microorganisms. The study is considered reliable as it was conducted using OECD Testing Guideline 209. The study was conducted using domestic activated sludge and gave a 30 minute EC₂₀ of 230 mg/L based on respiration inhibition on BPA 6.3EO. The weight of evidence indicates that the registered substance is not toxic to microorganisms.