Benzoic acid, 2-fluoro-5-(methylsulfonyl)-

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:

September 2012 - August 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-fluoro-5-methanesulfonylbenzoic acid

EC Number:

689-137-0

Cas Number:

247569-56-8

Molecular formula:

C8 H7 F O4 S

IUPAC Name:

2-fluoro-5-methanesulfonylbenzoic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

BMG sample no. M1302-01397-01

Lot no. 270002C

CAS no. 247569-56-8

Purity 99.86%; treated as 100% pure

Water solubility Soluble

Test substance storage At room temperature, protected from light

Retest date 20 February 2014

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Results and discussion

Any other information on results incl. tables

Cell concentrations (OD680) are presented in Table 2. The biomass increase is depicted in Figure 1.

The average specific growth rates over 3 days and the respective inhibition percentages are presented in Table 3. The section-by-section (days 0–1, 1–2 and 2- 3) specific growth rates are presented in Table 4.

The average yield over 3 days and the respective inhibition percentages are presented in Table 5. The test concentrations are presented in Table 6, whereas the physico-chemical data are indicated in Table 7.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The median growth inhibiting concentration (ErC₅₀/EyC₅₀) and the low-effect concentrations (ErC₁₀/EyC₁₀,ErC₂₀/EyC₂₀), based on the average specific growth rate and the yield (algal biomass production) within 3 days, of 2-Fluoro-5- (methylsulfonyl)benzoic acid to the green alga Desmodesmus subspicatus, were investigated over a period of 72 h.

Since 2-Fluoro-5-(methylsulfonyl)benzoic acid is soluble in water, a stock solution of the test material in algal medium was prepared. Test concentrations were prepared by dilution of this stock solution. The test substance concentrations were 12.5, 25, 50, 100 and 200 mg/l. Three parallel test vessels were used for each nominal test concentration.

HPLC analysis of 2-Fluoro-5-(methylsulfonyl)benzoic acid was performed at the beginning and after 24, 48 and 72 h of exposure. Measured concentrations at the beginning of the exposure were 12.0, 24.1, 47.2, 91.3 and 162 mg/l. The concentrations were satisfactorily maintained over the whole exposure period. Geometric mean concentrations over a period of 72 h (GM_0-72h) were 12.1, 24.1, 45.5, 86.7 and 164 mg/l (101, 100, 97, 95 and 101% of initial concentration, respectively).

The median effect concentration with respect to growth rate (ErC₅₀/0-3 days) of 2- Fluoro-5-(methylsulfonyl)benzoic acid to Desmodesmus subspicatus was estimated to be >164 mg/l geometric mean concentration (GM_0–72h).

The low effect concentrations with respect to growth rate, ErC₁₀ and ErC₂₀, were estimated to be >164 mg/l geometric mean concentration (GM0-72h), respectively.

The no observed effect concentration (NOErC) with respect to growth rate was determined to be 164 mg/l geometric mean concentration (GM_0-72h).

The median effect concentration with respect to yield (EyC₅₀/0–3 days) of 2-Fluoro- 5-(methylsulfonyl)benzoic acid to Desmodesmus subspicatus was estimated to be >164 mg/l geometric mean concentration (GM_0–72h).

The low effect concentrations with respect to yield, EyC₁₀ and EyC₂₀, were estimated to be >164 mg/l geometric mean concentration (GM_0-72h), respectively.

The no observed effect concentration (NOEyC) with respect to yield was determined to be 164 mg/l geometric mean concentration (GM_0–72h). Algal growth stimulation was observed at all test concentrations.