Trichloroacetyl chloride

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

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

No analytical monitoring was performed to check the stability of the test item concentration during the study. However, this article reports a series of algal toxicity tests for different species. Analytical monitoring was performed on 2 species (not P. subcapitata) in BBM media and demonstrated that at 0 and 72h all test concentrations (0.1 - 100 mg/L) were within 80% of the nominal. As the test conditions were the same among the tests except the test media, it is expected that the test concentrations of TCA remains stable for the test with P. subcapitata.

Data source

Reference

Reference Type:

publication

Title:

Toxicity of haloacetic acids to freshwater algae

Author:

Roberts JF, van Egmond R, Price OR

Year:

2010

Bibliographic source:

Ecotoxicology and Environmental Safety 73 (2010) 56–61

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

not specified

Remarks:

In the publication, GLP status is not mentioned, but the test is conducted following the guideline

Test material

Test material information

Constituent 1

Reference substance name:

Trichloroacetic acid

EC Number:

200-927-2

EC Name:

Trichloroacetic acid

Cas Number:

76-03-9

Molecular formula:

C2HCl3O2

IUPAC Name:

trichloroacetic acid

Test material form:

not specified

Details on test material:

The test chemical was obtained from Sigma-Aldrich, Gillingham, UK.

Sampling and analysis

Analytical monitoring:

no

Remarks:

A series of algal toxicity tests were conducted for different species. Analytical monitoring was performed on 2 species only (not P. subcapitata) and in BBM media.

Test solutions

Vehicle:

no

Details on test solutions:

Stock solution of 500 mg/L of TCA was prepared in purified water. The pH of the stock solution was adjusted to 7.0 +/- 0.5 using 1M NaOH to minimise the impact on media pH prior to the starting toxicity studies. The test chemical was soluble in water. Tests solutions were prepared by diluting the appropriate amount of stock solution with ISO media.

Test organisms

Test organisms (species):

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

Details on test organisms:

Laboratory culture of P. subcapitata (CCAP 278/4) was obtained from the Culture Collection of Algae and Protozoa, Oban, Scotland, UK.
To ensure the algae were in the exponential growth phase when used to inoculate the test solutions, pre-inoculum cultures were prepared six days prior to the start of the test by suspending the algae in 150mL of relevant test medium. Three days prior to the start of the study, fresh inoculum cultures were prepared by adding the required volume of the pre-inoculum suspension to a further 150mL of growth medium to give a nominal cell density of 1 x 10E4 cells/mL. The inocula were maintained under test conditions until the start of the test. All cultures were visually inspected for contamination and only log-phase algae were used for starting the toxicity tests.

Study design

Test type:

static

Water media type:

freshwater

Remarks:

ISO media

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

Not reported.

Test temperature:

23°C +/- 2°C

pH:

average at the start of the algal incubations : 7.58
average at the end of the algal incubations : 7.64

Dissolved oxygen:

Not reported

Salinity:

Not reported

Conductivity:

Not reported

Details on test conditions:

At the beginning of the test, each flask was inoculated with 1x10E4 cells/mL. Tests were carried out under continuous uniform illumination with a light intensity of ca.130 mE/m2 s. The temperature in the media during the test period was 23°C (+/- 2°C). The flasks were rotated at approximately 100 rpm to keep the cells in suspension and ensure an adequate gas exchange. Cell densities were determined at 0, 24, 48 and 72h using the Z2 Coulter Counter (Beckman Coulter,UK).

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

16.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% fudicial interval : 10 - 32.7 mg/L

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% fudicial interval : 3.3 - 7.8 mg/L

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

The biomass and growth rate for P. subcapitata exposed to TCA followed typical concentration–response relationships.
Validity criteria :
- The cell densities of P.subcapitata in the ISO media controls increased by182 fold.
- Coefficient of variation for section-by-section specific growth rates in control cultures (days 0–1, 1–2 and 2–3 days) : 14.1
- Coefficient of variation of average specific growth rates during the whole test period in replicate control cultures : 6.1

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

No data

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

see the field "details of results"

Conclusions:

Under the test conditions, the 72h NOEC was 3 mg/L and the 72h ErC50 was 16.2 mg/L.

Executive summary:

The objective of the study was to determine the effect of trichloroacetic acid (TCA) on the growth of the freshwater green alga, Pseudokirchneriella subcapitata. Procedures used in this study followed the OECD Guideline for Testing of Chemicals #201.

The 72-hour NOEC for growth rate was determined to be 3 mg/L. The 72-hour ErC50 value was determined to be 16.2 mg/L.

The OECD validation criteria were fulfilled.

In these test conditions, TCA is harmful to algae.