2,2'-[(4-methylphenyl)imino]bisethanol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Refer to the analogue approach justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (CO2 evolution)

Value:

1.5

Sampling time:

29 d

Remarks on result:

other: HCl added on the 28th day (last CO2-measurement on the 29th day)

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Based on the available read-across data it is concluded that the target substance is not readily biodegradable under the conditions of the modified Sturm test.

Executive summary:

The readily biodegradation of the source substance Accelerator (PT 25E or PT 25E/2) was assessed with a modified Sturm test (CO2 evolution) according to OECD guideline 301 B and GLP principles. A single test concentration of 12 mg/L (as TOC) was tested during 28 days. Based on the obtained results, Accelerator (PT 25E or PT 25E/2) was not readily biodegradable. The study is considered to be reliable without restrictions.

The target substance is expected to have a similar environmental fate profile as the source substance based on the high degree of structural and chemical similarity between the source and the target substances. Therefore, it is concluded that the target substance is not readily biodegradable according to OECD guideline criteria.

Description of key information

Not readily biodegradable (1.5% in 28 d, OECD 301 B, act. sludge); read-across

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

There is no study available, in which the ready biodegradability of the target substance N,N-Dihydroxyethyl-p-toluidine (CAS 3077-12-1) was assessed. Therefore, read-across to the structurally and chemically closely related source substance Reaction mass of 2,2'-[(4-methylphenyl)imino]bisethanol and Ethanol 2-[[2-(2-hydroxyethoxy)ethyl](4-methylphenyl)amino]- (EC 911-490-9) was performed in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5 in order to meet the standard information requirements laid down in Annex VIII of REACh Regulation (EC) No 1907/2006. Based on the high degree of physico-chemical similarity between the target and source substance, the selected source substance is considered a suitable representative for the assessment of the ready biodegradability of the target substance. A detailed read-across approach justification is provided in IUCLID section 13.

 

In the available study with the source substance, ready biodegradation was assessed by means of the modified Sturm test in which 12 mg/L test item (as TOC) was inoculated with activated sludge microorganisms (10 mL/L sludge supernatant) for 28 d according to OECD guideline 301 B and GLP principles. A procedure and a toxicity control were run in parallel.

After 28 d, the test item was degraded by 1.5% (CO2 evolution). The procedure and toxicity control confirmed the suitability of the inoculum and test design. Based on the obtained results, the source substance was not readily biodegradable according to OECD guideline criteria.

Since the target substance is the main constituent of the source substance it is concluded that the target substance N,N-Dihydroxyethyl-p-toluidine (CAS 3077-12-1) is not readily biodegradable according to OECD guideline criteria.