Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test conditions

Test temperature:
23 ± 2°C
Nominal and measured concentrations:
Target concentrations (mg.L-1)
Control
Solvent control
0.3
0.95
3.05
9.77
31.25
100
Details on test conditions:
Light: continuous illumination between 4440 and 8880 lux

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.14 mg/L
Nominal / measured:
nominal
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.53 mg/L
Nominal / measured:
nominal
Basis for effect:
biomass
Remarks:
yield
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.15 mg/L
Nominal / measured:
nominal
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.11 mg/L
Nominal / measured:
nominal
Basis for effect:
biomass
Remarks:
yield

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The objective of this study was to assess the effects of test item Isoamyl Nitrite on the growth of Pseudokirchneriella subcapitata over a period of 72 hours according to OECD 201 Guideline. Pseudokirchneriella subcapitata is a freshwater green algae that is recommended by the OECD Guideline 201.

Since the substance is volatile and is not soluble in under conditions of the test, the test was carried out in closed bottles and the substance was added by injection through the septum.

Test item quantification was performed according to a validated analytical method (final report RRCo-000234_01) on a GC-MS/MS from Agilent (GC 7890b and MS triple quadrupole 7000b or c) as mass spectrometry detection was found suitable to measure Isoamyl Nitrite concentrations at 0, 24, 48 and 72 hours.

The effects of Isoamyl Nitrite at the definitive nominal concentrations of 0; 0.3; 0.95; 3.05; 9.77; 31.25 and 100 mg.L-1 to Pseudokirchneriella subcapitata were investigated under laboratory conditions.

Due to the instability of test item, the calculations were performed on the nominal concentrations.

Results are the following:
Isoamyl Nitrite

ECgrowth rate 10-72h (95% confidence limits): 0.15 mg.L-1 (95% confidence limits: 0.05 – 0.30 mg.L-1)
ECgrowth rate 50-72h (95% confidence limits): 2.14 mg.L-1 (95% confidence limits: 1.59 – 3.33 mg.L-1)
ECyield 10-72h (95% confidence limits): 0.11 mg.L-1 (95% confidence limits: 0.02 – 0.22 mg.L-1)
ECyield 50-72h (95% confidence limits): 0.53 mg.L-1 (95% confidence limits: 0.31 – 0.75 mg.L-1)

EC = effect concentration

The study is valid since the growth multiplication factor in the control within the 72-hour test period was higher than 16 (actual value: 17), the coefficient of variation of the average specific growth rates in the control was less than 7% (actual value: 6.89%)

The mean coefficient of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3) in the control was not reached (actual value: 67.08% after 72h, the criteria is fixed at < 35%). Indeed, the bottles being sacrificial, the daily monitoring was not on the same bottle. It is therefore not significant to follow the growth of a replicate in time because it is not the same bottle.

This is no impact on the study, the other criteria were reached, so the study is valid.