3-[(4-aminobenzoyl)amino]propanoic acid

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:

Start: 02/07/2018 - End: 09/07/2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Green alga
- Strain: SAG 61:81
- Source: laboratory culture


ACCLIMATION
- Acclimation period:
- Culturing media and conditions: Culture medium was kept in 250ml Erlenmeyer flasks in the following conditions:
-Temperature: 23° ± 2°C
- Lighting: lighting greater than 4300 lux
- Sirring: steady with electrical stirrer

Test type:

static

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

23 ± 2°C
Refer to results table below

pH:

Refer to results table below

Nominal and measured concentrations:

100.0 mg/l (nominal concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Initial cells density: 10^4 cells/ml
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Deionized water
- Culture medium different from test medium: No


OTHER TEST CONDITIONS
- Light intensity and quality: Continuous - with flourescent lamp 8000 lux



TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 5 ten-fold dilutions from 100 mg/l to 0.01 mg/l.
- Results used to determine the conditions for the definitive study: Yes

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Stability of the test item:

The test item was considered stable because the measured concentrations of the test item at the end of the test has been maintained within ± 20% at the beginning of the test.

The test item resulted stable during the test, therefore the statistical analysis (EC50) has been performed using the nominal concnetration at T=0.

Nominal conc.	Measured conc (mg/l) T=0	Measured conc. (mg/l) T=72 H	% concentration variation	Stability
Treated	102.70	104.02	1.28	Stable

Algal density (cells/ml) in treated group

Time (h)	Treated group
	1	2	3	4	5	6
0	1.0E+04	1.0E+04	1.0E+04	1.0E+04	1.0E+04	1.0E+04
24	7.7E+04	7.7E+04	8.0E+04	7.8E+04	7.5E+04	7.2E+04
48	8.3E+05	7.2E+05	8.5E+05	9.7E+05	8.5E+05	8.3E+05
72	2.3E+06	2.2E+06	2.2E+06	2.1E+06	2.2E+06	2.3E+06

Algal density (cells/ml) in control group:

Time (h)	Control group
	1	2	3	4	5	6
0	1.0E+04	1.0E+04	1.0E+04	1.0E+04	1.0E+04	1.0E+04
24	6.8E+04	9.2E+04	8.3E+04	8.5E+04	8.7E+04	8.0E+04
48	8.7E+05	8.3E+05	8.2E+05	8.8E+05	7.8E+05	8.2E+05
72	2.4E+06	3.1E+06	2.6E+06	2.8E+06	2.5E+06	2.6E+06

Determination of pH:

pH
Control				Treated
Replica	Test start	Test end	∆pH	Replica	Test start	Test end	∆pH
1	7.78	7.51	0.27	1	6.12	4.98	1.14
2	7.77	7.52	0.25	2	6.13	4.97	1.16
3	7.77	7.54	0.23	3	6.13	5.01	1.12
4	7.78	7.49	0.29	4	6.10	5.01	1.09
5	7.79	7.51	0.28	5	6.13	4.96	1.17
6	7.77	7.48	0.29	6	6.12	4.94	1.18

Temperature recorded

Time (h)	Temperature °C
0	23.0
24	23.1
48	22.9
72	23.1

Validity criteria fulfilled:

yes

Conclusions:

The obtained reuslts in compliance with assay validity criteria, showed that algae EC50 of the nominal concentraiton of the test item '4-aminobenzoyl-b-alanine' after 72 hours is >100 mg/L.

Description of key information

A GLP study was performed in accordance with OECD Guideline 201 to assess the toxicity of the test material, 4 -aminobenzoyl-b-alanine, to algae. According to the results of the test, the EC50 (72 h) was > 100 mg/L (nominal).

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L