N,N-Di-(2-Ethylhexyl)-amino Isostearamide

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 September 2019 - 09 November 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Analysis of the 18, 32, 56 and 100 mg/L loading rate WAF test preparations at 0 and 72 hours

showed measured test concentrations of less than the limit of quantification (LOQ) of the

analytical method employed were obtained which was determined to be 0.00050 mg/L.

Measured concentrations of 0.0019 and 0.00070 mg/L were obtained from the 10 mg/L

loading rate WAF test preparations at 0 and 72 hours respectively.

Measured concentrations of less than the LOQ do not infer that no test item was in solution,

just that any which was present, was so at a concentration of less than 0.00050 mg/L.

Given that the toxicity cannot be attributed to a single component or a mixture of components

but to the test item as a whole, the results were based on nominal loading rates only.

Exposure of Raphidocelis subcapitata to the test item gave the following results:

Response Variable	EL10 (mg/L)	EL20 (mg/L)	EL50 (mg/L)	No Observed Effect Loading Rate (NOEL) (mg/L)	Lowest Observed Effect Loading Rate (LOEL) (mg/L)
Growth Rate	>100	>100	>100	100	Not determined
Yield	63	>100	>100	56	100

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the growth of Raphidocelis subcapitata has been investigated over a 72-Hour period and a EL50 >100 mg/L concluded

Executive summary:

The effect of the test item on the growth of Raphidocelis subcapitata has been investigated over a 72-Hour period and a EL50 >100 mg/L concluded