[No public or meaningful name is available]

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

effects on growth of an additional algal species

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological and ecotoxicological properties because they share structural similarities with common functional groups: quaternary amines, esters, and fatty acid chains varying in their length and degree of (un)saturation. Moreover, the fatty acid chains are chemically simple structures which have no structural alerts for toxicity, and which are closely related to substances of known low toxicity (i.e. stearic acid, oleic acid, linoleic acid, linolenic acid). Furthermore, the substances can be expected to have comparable breakdown products (MDEA or MDIPA and long chain fatty acids).

This read-across hypothesis corresponds to scenario 2 - different compounds have qualitatively and quantitatively the same type of effects - of the read-across assessment framework i.e. properties of the target substance MDEA-Esterquat C18 unsatd. are predicted to be similar to those of the source substances MDIPA Esterquat C18 unsatd., MDEA-Esterquat C16-18 and C18 unsatd. and MDIPA-Esterquat C16-18 and C18 unsatd.

Therefore, read-across from the available physicochemistry, toxicity and ecotoxicity studies with the source substances MDIPA Esterquat C18 unsatd., MDEA-Esterquat C16-18 and C18 unsatd. and MDIPA-Esterquat C16-18 and C18 unsatd. are considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance MDEA-Esterquat C18 unsatd., in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.


2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
please refer to read-across justification attached to Iuclid section 13

3. ANALOGUE APPROACH JUSTIFICATION
please refer to read-across justification attached to Iuclid section 13

4. DATA MATRIX
please refer to read-across justification attached to Iuclid section 13

Reason / purpose for cross-reference:

exposure-related information

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.2 mg/L

95% CI:

>= 0.24 - <= 6

Nominal / measured:

meas. (TWA)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.54 mg/L

95% CI:

>= 0.1 - <= 2.9

Nominal / measured:

meas. (TWA)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.39 mg/L

Nominal / measured:

meas. (TWA)

Basis for effect:

growth rate

Conclusions:

Based on read-across from the source substances MDIPA Esterquat C18 unsatd. and MDEA-Esterquat C16-18 and C18 unsatd. The 72h ErC50 of the target substance MDEA-Esterquat C18 unsatd. in Pseudokirchneriella subcapitata is 1.2 mg/L, the 72 h ErC10 = 0.54 mg/L, the 72 h NOErC = 0.39 mg/L.

Description of key information

Based on read-across from the source substances MDIPA Esterquat C18 unsatd. and MDEA-Esterquat C16-18 and C18 unsatd. The 72h ErC50 of the target substance MDEA-Esterquat C18 unsatd. in Pseudokirchneriella subcapitata is 1.2 mg/L, the 72 h ErC10 = 0.54 mg/L, the 72 h NOErC = 0.39 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

1.2 mg/L

EC10 or NOEC for freshwater algae:

0.54 mg/L

Additional information

No experimental data are available for the target substance MDEA-Esterquat C18 unsatd. However, toxicity studies in algae are available for the structurally related source substances MDIPA-Esterquat C16-18 and C18 unsatd., and MDIPA-Esterquat C18 unsatd. 

A justification for read-across is attached to Iuclid section 13.

 

In a 72 hour acute toxicity study the cultures of Pseudokirchneriella subcapitata were exposed to MDIPA-Esterquat C16-18 and C18 unsatd. at nominal concentrations of 0 (control), 0.25, 0.80, 2.5, 8.0 and 25 mg/L, corresponding to measured (TWA) 0.29, 0.91, 2.7, 6.2 and 25 mg/L in the presence of 4 mg/L humic (<2 mg/L DOC) acid under static conditions in accordance with OECD guideline 201.

Microscopic observations revealed no abnormalities.

The NOEC, EC10 and EC50 based on growth rate were 2.7, 3.2 (95% c.i. 2.5-4.1 mg/L) and 8.1 mg/L (95% c.i. 6.4-10 mg/L), respectively.

The NOEC, EC10 and EC50 based on based on yield were 0.91, 1.3 (95% c.i. 0.45-3.7 mg/L) and 4.4 mg/L (95% c.i. 1.6-12 mg/L), respectively.

All effect levels are given based on measured (TWA) concentrations.

 

In a 72 hour acute toxicity study the cultures of Pseudokirchneriella subcapitata were exposed to MDIPA Esterquat C18 unsatd. at nominal concentrations of 0 (control), 0.10, 0.32, 1.0, 3.2 and 10 mg/L, corresponding to measured (TWA) 0.042, 0.14, 0.39, 1.3 and 1.7 mg/L in the presence of 4 mg/L humic acid under static conditions in accordance with OECD guideline 201.

Microscopic observations revealed no abnormalities.

The NOEC, EC10 and EC50 based on growth rate were 0.39, 0.54 (95% c.i. 0.10-2.9 mg/L) and 1.2 mg/L (95% c.i. 0.24-6.0 mg/L), respectively.

The NOEC, EC10 and EC50 based on based on yield were 0.39, 0.49 (95% c.i. 0.22-1.0 mg/L) and 0.95 mg/L (95% c.i. 0.44-2.1 mg/L), respectively.

All effect levels are given based on measured (TWA) concentrations.

 

Conclusion

Based on read-across from the source substances MDIPA Esterquat C18 unsatd. and MDEA-Esterquat C16-18 and C18 unsatd. The 72h ErC50 of the target substance MDEA-Esterquat C18 unsatd. in Pseudokirchneriella subcapitata is 1.2 mg/L, the 72 h ErC10 = 0.54 mg/L, the 72 h NOErC = 0.39 mg/L.