Formaldehyde, oligomeric reaction products with 4,4'-isopropylidenediphenol and m-phenylenebis (methylamine)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Test organisms (species):

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

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 degrees Celcius

pH:

7.6-8.6

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

54 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

29 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the growth of Pseudokirchneriella subcapitata has been investigated over a 72-Hour period and based on the geometric mean measured test concentrations gave the following results:
Response Variable EC50 (mg/L) 95% Confidence Limits (mg/L) No Observed Effect Concentration (NOEC) (mg/L) Lowest Observed Effect Concentration (LOEC) (mg/L)
Growth Rate 54 52 - 55 25 50
Yield 29 26 - 33 6.25 12.5

Executive summary:

Introduction

A study was performed to assess the effect of the test item on the growth of the green alga Pseudokirchneriella subcapitata. The method followed that described in the OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test" referenced as Method C.3 of Commission Regulation (EC) No 761/2009.

Methods

Due to the low aqueous solubility and complex nature of the test item for the purposes of the test the test item was prepared as a Water Accommodated Fraction (WAF).

Following a preliminary range-finding test, Pseudokirchneriella subcapitata was exposed to Water Accommodated Fractions (WAFs) of the test item over a range of nominal loading rates of 6.25, 12.5, 25, 50 and 100 mg/L (three replicate flasks per concentration) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1 °C.

Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter® Multisizer Particle Counter.

Results

Analysis of the test preparations at 0 hours showed measured concentrations to range from less than the limit of quantification (LOQ) of the analytical method employed, determined to be 0.0061 mg/L, to 13 mg/L. Concentrations in the range of 0.015 to 14 mg/L were obtained at 72 hours.

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 Pseudokirchneriella subcapitata to the test item gave the following results based on the geometric mean measured test concentrations:

Response Variable	EC50 (mg/L)	95% Confidence Limits (mg/L)	No Observed Effect Concentration (NOEC) (mg/L)	Lowest Observed Effect Concentration (LOEC) (mg/L)
Growth Rate	54	52 - 55	25	50
Yield	29	26 - 33	6.25	12.5

Description of key information

The effect of the test item on the growth of Pseudokirchneriella subcapitata has been investigated over a 72-Hour period and based on the geometric mean measured test concentrations gave the following results:

Response Variable	EC50 (mg/L)	95% Confidence Limits (mg/L)	No Observed Effect Concentration (NOEC) (mg/L)	Lowest Observed Effect Concentration (LOEC) (mg/L)
Growth Rate	54	52 - 55	25	50
Yield	29	26 - 33	6.25	12.5

Key value for chemical safety assessment

EC50 for freshwater algae:

29 mg/L