Dichlorotricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene, mixed isomers

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test material

Test material information

1

Reference substance name:

Dichlorotricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene, mixed isomers

EC Number:

249-236-8

EC Name:

Dichlorotricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene, mixed isomers

Cas Number:

28804-46-8

Molecular formula:

C16H14Cl2

IUPAC Name:

Reaction product of tricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene with chlorine

Test material form:

solid: granular

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

Before conducting the preliminary range finding study, test item was checked for solubility and precipitation. Test item was found to be insoluble in algal medium at the concentration of 0.1 mg/mL. Further solubility was checked in dimethyl formamide (DMF), acetone and Dimethyl sulfoxide (DMSO) and found to be soluble at 33.33 (Stock A), 25.57 (Stock B) and 22.22 (Stock C) mg/mL, respectively. Maximum solubility of test item found in dimethyl formamide (DMF) and acetone. Hence, test item soluble in DMF and acetone was further serially diluted in respective solvents and checked for precipitation in the test medium.
Stock solution A was serially diluted at the concentration of 16.33 (Stock D), 8.33 (Stock E), 4.16 (Stock F), and 2.08 (Stock G) mg/mL in DMF. These stock solutions were checked for precipitation test using algal medium. Precipitation was observed upto the concentration of 4.16 mg/mL, while no precipitation was observed at the concentrations of 2.08 mg/mL.
Stock solution B was serially diluted at the concentration of 14.29 (Stock H), 7.14 (Stock I) and 3.57 (Stock J) mg/mL in acetone. These stock solutions were checked for precipitation test using algal medium. Precipitation was observed upto the concentration of 7.14 mg/mL, while no precipitation was observed at the concentrations of 3.57 mg/mL.
Hence, the Acetone was used as vehicle for the study and the highest tested concentration was 0.357 mg/L.

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis 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

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.357 mg/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 0.357 mg/L

Effect concentrations 3

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 0.357 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

There was no significant alteration observed in algal growth (biomass), yield and growth rate of DPX-C (Di-Cloro-Di-p-Xililene) exposed group as compared to vehicle control group. The DPX-C (Di-Cloro-Di-p-Xililene) does not inhibit the growth of alga (Pseudokirchneriella subcapitata) up to the concentration of 0.357 mg DPX-C (Di-Cloro-Di-p-Xililene) of alga media. The EC50, NOEC and LOEC value was greater than 0.357 mg/L.

Executive summary:

This study was performed to assess the effects on the growth of the algaPseudokirchneriella subcapitatacaused by exposure under static conditions to the PX-C (Di-Cloro-Di-p-Xililene) according to the OECD guideline 201.

Exponentially growing cultures ofP. subcapitatawere exposed to nominal test concentrations of 0.0 (Control), 0.0 (Vehicle Control) and 0.357 mg/L. The algal cultures were assessed for the growth by visual cell count at 24, 48, and 72 h.

The stability of test item in test media was performed during method validation (JRF Study N° 228-2-13-14897) and test item in test media found to be stable up to 72 h (> 80% of nominal concentration). Test media was analysed for DPX-C (Di-Cloro-Di-p-Xililene) active ingredient concentration to monitor the concentration of test solution at 0 and 72 h during main study. The active ingredient concentration of test item in test media was within acceptable limit (> 80% of nominal concentration).

There was no significant alteration observed in algal growth (biomass), yield and growth rate ofDPX-C (Di-Cloro-Di-p-Xililene)exposed group as compared to vehicle control group. TheDPX-C (Di-Cloro-Di-p-Xililene)does not inhibit the growth of alga (Pseudokirchneriella subcapitata) up to the concentration of 0.357 mgDPX-C (Di-Cloro-Di-p-Xililene)of alga media. The EC₅₀, NOEC and LOEC value was greater than 0.357 mg/L.