4,4'-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with 3-aminomethyl-3,5,5-trimethylcyclohexylamine

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:

16 to 19 October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This is a GLP Guideline study. All the validity criteria were met. Analytical test material characterization and quantification was included in the study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Principles of method if other than guideline:

BADGE-IPD (#33) possesses multiple secondary amines and potentially has cationic properties. The testing regime followed OECD (2000) guidance with respect to testing such substances and the test solutions were amended with either 0 or 10 mg/L humic acid. Humic acid is commonly used when testing cationic substances because the dissolved organic carbon binds with cationic chemicals, neutralizes the charges, reduces toxicity and makes cationic chemicals less bioavailable.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Because BADGE IPD (#33) is a multi-component substance of limited solubility, WAFs were created and analyzed via non-purgable organic carbon (NPOC) and all values reported are nominal. This method is outlined in the OECD guidance (No. 23) on Aquatic Testing of Difficult Substances and Mixtures. NPOC was measured in test solutions at test initiation and termination.

Vehicle:

no

Details on test solutions:

A preliminary non-GLP trial indicated that a dosing (loading rate) of 100 mg BADGE-IPD (#33)/L required 24 hours of stirring to reach an equilibrium in water-soluble components (i.e., a change of <20% measured dissolved organic carbon concentrations between two sampling points); therefore, the WAF preparations for all test solutions were stirred for approximately 24 hours prior to test initiation.

Test organisms (species):

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

Details on test organisms:

The algal inoculum for the test was prepared from a 4-day old stock culture for both the test without humic acid and the test with 10 mg humic acid/L. Enough of the inoculum was used to achieve an initial cell density of approximately 10,000 cells/mL.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

None

Test temperature:

Test without humic acid: 22 – 23°C
Test with humic acid: 23 – 24°C

pH:

Test without humic acid: 7.0 – 7.4
Test with humic acid: 7.0 – 7.5

Nominal and measured concentrations:

Test without humic acid nominal concentrations: 0 (control), 0.050, 0.11, 0.24, 0.54, 1.2, and 2.6 mg BADGE-IPD (#33) /L, prepared from a 2.6 mg/L WAF

Test with humic acid: 0 (control), 3.1, 6.3, 13, 25, 50, and 100 mg BADGE-IPD (#33)/L, prepared from a 100 mg/L WAF

Details on test conditions:

Test without humic acid: Temperatures during the exposure period ranged from 22 to 23 ºC. Light intensity ranged from 4450 to 5560 lux. The pH ranged from 7.1 to 7.2 at test initiation and from 7.1 to 7.4 and 7.0 to 7.2 in replicates both with and without algae at test termination, respectively.

Test with humic acid: Temperatures during the exposure period ranged from 23 to 24 ºC. Light intensity ranged
from 4490 to 5910 lux. The pH ranged from 7.2 to 7.5 at test initiation and from 7.2 to 7.3 and 7.0 to 7.2 in replicates both with and without algae at test termination, respectively. The pH of the 100 mg/L loading rate was 9.3 prior to adjustment to 7.5 with hydrochloric acid.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

79.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Test with humic acid

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

11.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: Test with humic acid

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

11.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: Test with humic acid

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

3.1

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Test with humic acid

Details on results:

Test without humic acid
72 hour cell density EL50 = 0.967 mg/L; NOELR = Not calculable
0-72-hour cell yield EyL50 = 0.972 mg/L; NOELR = Not calculable
0-72 hour growth inhibition ErL50 = 1.67 mg/L; NOELR = Not calculable
Test with humic acid
72 hour cell density EL50 = 11.3 mg/L; NOELR = 3.1 mg/L
0-72-hour cell yield EyL50 = 11.1 mg/L; NOELR = 3.1 mg/L
0-72 hour growth inhibition EL50 = 79.4 mg/L; NOELR = 3.1 mg/L

Reported statistics and error estimates:

Test without humic acid:
For cell density at 72 hours, the calculated EL10, EL20 and EL50 (95% confidence intervals) were 0.515 (0.417 – 0.636), 0.640 (0.538 – 0.760), and 0.967 (0.867 – 1.08) mg BADGE-IPD (#33)/L. For cell yield at 0-72 hours, the calculated EyL10, EyL20 and EyL50 (95% confidence
intervals) were 0.548 (0.444 – 0.675), 0.667 (0.562 – 0.791), and 0.972 (0.874 – 1.08) mg BADGE-IPD (#33)/L, respectively. Between 0 and 72 hours, the calculated ErL10, ErL20, and ErL50 (95% confidence intervals) were 0.924 (0.810 – 1.06), 1.13 (1.02 – 1.26), and 1.67 (1.57 – 1.78) mg
BADGE-IPD (#33)/L, respectively.
Test with humic acid
For cell density at 72 hours, the calculated EL10, EL20 and EL50 (95% confidence intervals) were <3.1 (<3.1 – 3.28), 4.16 (<3.1 – 5.43), and 11.3 (9.49 – 13.0) mg BADGE-IPD (#33)/L. For cell yield at 0-72 hours, the calculated EyL10, EyL20 and EyL50 (95% confidence intervals) were <3.1 (<3.1 – 3.37), 4.24 (<3.1 – 5.49), and 11.1 (9.42 – 12.8) mg BADGE-IPD (#33)/L, respectively. Between 0 and 72 hours, the calculated ErL10, ErL20, and ErL50 (95% confidence intervals) were 4.82 (<3.1 – 7.96), 12.6 (8.89 – 17.9), and 79.4 (65.7 – 95.9) mg BADGE-IPD (#33)/L, respectively.

The addition of 10 mg humic acid/L reduced the toxicity of BADGE-IPD (#33) for each of the endpoints examined between 11- and 47-fold. In line with the recommendation by relevant guidelines (OECD, 2000 and USEPA, 2010) the results observed in the exposure

amended with humic acid are predicted to be more more environmentally realistic and, therefore, relevant in determining the potential effect of the test material in the environment.

Validity criteria fulfilled:

yes

Executive summary:

The purpose of this study was to assess the effects of BADGE-IPD (#33) to the freshwater green alga, Pseudokirchneriella subcapitata, over a 72-hour static exposure period. These data were used to determine EL50 (the loading rate causing 50% inhibition) values for 72 - hour cell density, 0-72-hour cell yield, and average specific growth rate from 0 to 72 hours.

When possible, NOELR (no-observable-effect loading rate, the highest loading rate not significantly different from the controls) values were determined. BADGE-IPD (#33) has low aqueous solubility and therefore test solutions were prepared from a water

accomodated fraction (WAF). BADGE-IPD (#33) possesses cationic properties and was, therefore, tested in line with the OECD (2000) recommendation for testing cationic properties for the mitigating effect of humic acid. The results of the test are as follows:

Without Humic Acid

72 hour cell density EL50 = 0.967 mg/L; NOELR = Not calculable

0-72-hour cell yield EyL50 = 0.972 mg/L; NOELR = Not calculable

0-72 hour growth inhibition EL50 = 1.67 mg/L; NOELR = Not calculable

With 10 mg Humic Acid/L

72 hour cell density EL50 = 11.3 mg/L; NOELR = 3.1 mg/L

0-72-hour cell yield EyL50 = 11.1 mg/L; NOELR = 3.1 mg/L

0-72 hour growth inhibition ErL50 = 79.4 mg/L; NOELR = 3.1 mg/L

For the test run without humic acid, a NOELR could not be reported because the repsonse for each endpoint was non-monotonic.

Description of key information

A single freshwater green algae study 

Key value for chemical safety assessment

EC50 for freshwater algae:

79.4 mg/L

EC10 or NOEC for freshwater algae:

3.1 mg/L