2,6,10,15,19,23-hexamethyltetracosane

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)

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)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,6,10,15,19,23-hexamethyltetracosane

EC Number:

203-825-6

EC Name:

2,6,10,15,19,23-hexamethyltetracosane

Cas Number:

111-01-3

Molecular formula:

C30H62

IUPAC Name:

2,6,10,15,19,23-hexamethyltetracosane

Test material form:

other: liquid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Conc. based on:

other: loading rate

Any other information on results incl. tables

At the start of the test, the analytically determined concentration of Squalane (CAS 111-01-3) in the undiluted filtrate was 9.2 μg/L. At the end of the test, the measured test item concentration in the test medium was 6.1 μg/L. The mean measured concentration was calculated as geometric mean between the measurements at the start and the end of the test to be 7.5 μg/L. The biological results were related to the loading rate of 100 mg/L and to the mean measured test concentration of 7.5 μg/L.

The test item had no statistically significant inhibitory effect on the growth of the algae (average growth rate and yield) during the test period of 72 hours at the loading rate of 100 mg/L (mean measured concentration of 7.5 μg/L) according to results of Dunnett t-test.

The 72-hour LOEC was higher than the loading rate of 100 mg/L (mean measured concentration of 7.5 μg/L), respectively higher than the maximum concentration of the test item which could be dissolved in the test water.

The microscopic examination of the algal cells at the end of the test showed no difference between the algae growing in the undiluted filtrate and the algal cells in the control. The shape and size of the algal cells were obviously not affected by the test item.

The biological results can be summarized as follows, based on the loading rate of 100 mg/L and on the mean measured concentration of 7.5 μg/L.

Parameter	Growth rate		Yield
	Loading rate (mg/L)	Mean measured concentration (μg/L)	Loading rate (mg/L)	Mean measured concentration (µg/L)
EC50	>100	>7.5	>100	>7.5
NOEC	≥ 100	≥ 7.5	≥ 100	≥ 7.5
LOEC	>100	>7.5	>100	>7.5

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the test item Squalane (CAS 111-01-3) had no toxic effects on Pseudokirchneriella subcapitata during the 72-hour test period up to a loading rate of 100 mg/L (mean measured concentration of 7.5 μg/L) respectively up to its solubility limit in the test water under the present test conditions.

Executive summary:

The influence of the test item Squalane (CAS 111-01-3) on the growth of the freshwater green algal species Pseudokirchneriella subcapitata was investigated in a 72-hour static test according to the OECD Guideline 201 (2006) and the Commission Regulation (EC) No 761/2009, C.3. Due to the low water solubility of the test item, a dispersion of the test item with the loading rate of 100 mg/L was continuously stirred at room temperature in the dark over 96 hours. This dispersion was filtered through a membrane filter (pore size 0.45 μm). The undiluted filtrate with the loading rate of 100 mg/L and dilutions 1:2.2, 1:4.6, 1:10 and 1:22 were used as test media. Additionally, a control was tested in parallel. Since the test item was supposed to be volatile, the test was performed in a closed system as a pre-caution. The preparation of the test media was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000. Only the highest loading rate was analytically determined as this test concentration was determined to be the NOEC in this test. At the start of the test, the analytically determined concentration of Squalane (CAS 111-01-3) in the undiluted filtrate was 9.2 μg/L. At the end of the test, the measured test item concentration in the test medium was 6.1 μg/L. The mean measured concentration was calculated as geometric mean between the measurements at the start and the end of the test to be 7.5 μg/L The biological results were related to the loading rate of 100 mg/L and to the mean measured test concentration of 7.5 μg/L. In conclusion, the test item Squalane (CAS 111-01-3) had no toxic effects on Pseudokirchneriella subcapitata during the 72-hour test period up to a loading rate of 100 mg/L (mean measured concentration of 7.5 μg/L) respectively up to its solubility limit in the test water under the present test conditions.