2-tetradecyloxirane, reaction products with boric acid

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13-08-2012 to 17-10-2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L
- Sampling method: Water samples were taken from the control and 100 mg/L loading rate WAF test vessel at 0 (fresh media), 24 (old media), 72 (fresh media) and 96 (old media) hours for quantitative analysis. Duplicate samples, and samples at 24 (fresh media), 72 (old media) and 48 hours (old and fresh media), were also taken.
- Sample storage conditions before analysis: All samples were stored at approximately -20°C prior to analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to the low aqueous solubility and complex nature of the test item for the purposes of the range-finding test the test item was prepared as a Water Accommodated Fraction (WAF). An amount of test item (2100 mg) was added to the surface of 21 L of dechlorinated tap water to give the 100 mg/L loading rate. After the addition of the test item, the dechlorinated tap water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixture allowed to stand for 1 hour. Microscopic observations made on the WAF indicated that a significant amount of dispersed test item was present in the water column and hence it was considered justifiable to remove the WAF by filtering through a glass wool plug (2-4 cm in length). A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. A glass wool plug was inserted into the opposite end of the tubing and the WAF removed by mid-depth siphoning (the first 75-100 mL discarded) to give the 100 mg/L loading rate WAF. Microscopic observations of the WAF were performed after filtering and showed that the glass wool plug had removed all of the undissolved test item present in the WAF.
- Controls: The control group was maintained under identical conditions but not exposed to the test item.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout
- Strain: Oncorhynchus mykiss
- Age at study initiation (mean and range, SD): Juvenile rainbow trout (≤ 12 months)
- Length at study initiation (mean, SD): 5.0±0.3 cm
- Weight at study initiation (mean, SD): 1.69±0.30 g
- Feeding during test: No

ACCLIMATION
- Acclimation period: 19-09-2012 to 30-09-2012
- Acclimation conditions (same as test or not): Yes
- Type and amount of food: Commercial trout pellets, ad libitum
- Feeding frequency: Daily but discontinued approximately 24 hours prior to the start of the definitive test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Approximately 150 mg/L as CaCO3

Test temperature:

14 °C

pH:

7.7-8.1

Dissolved oxygen:

9.3-10.1 mg O2/L

Salinity:

Not applicable. Study was performed in fresh water.

Nominal and measured concentrations:

Nominal concentration: 100 mg/L LR WAF

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 litre covered glass aquaria
- Aeration: The test vessels were aerated via narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): Test solutions replaced every 24 hours
- No. of organisms per vessel: Seven
- No. of vessels per concentration (replicates): Single
- No. of vessels per control (replicates): Single
- Biomass loading rate: 0.59 g bodyweight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water: Laboratory tap water was dechlorinated by passage through an activated carbon filter (Purite Series 500), partly softened (Elga Nimbus 1248D Duplex Water Softener) and passed through a series of computer controlled plate heat exchangers to achieve the required temperature.

EQUIPMENTS:
- The pH and dissolved oxygen concentration were measured using a Hach HQ30d Flexi handheld meter.
- The temperature was measured using a Hanna Instruments HI 93510 digital thermometer.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours of continuous artificial light and 8 hours continuous darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Any mortalities and sub-lethal effects of exposure were recorded at 3, 6, 24, 48, 72 and 96 hours after the start of exposure. The criteria of death were taken to be the absence of both respiratory movement and response to physical stimulation.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 100 mg/L (nominal loading rate)
- Results used to determine the conditions for the definitive study: The results of range-finding tests showed no mortalities at the 100 mg/L loading rate WAF. Based on this information, a single loading rate of 100 mg/L using a stirring period of 23 hours followed by a 1-hour standing period was selected for the definitive test.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality in test or control groups: None
- The results of the definitive test showed the highest loading rate resulting in 0% mortality to be greater than or equal to 100 mg/L loading rate WAF. The No Observed Effect Loading rate (NOEL) was 100 mg/L loading rate WAF.

Results with reference substance (positive control):

Not applicable

Sublethal observations / clinical signs:

- Validation of Mixing Period: Pre-study investigational work indicated that there was no significant increase in the amount of total organic carbon by extending the preparation period for longer than 24 hours.

- Chemical analysis results: Analysis of the 0 (fresh media), 24 (old media), 72 (fresh media) and 96 (old media) hour samples showed measured concentrations of 11.2, 11.5, 23.2 and 23.1 mg/L (equivalent to 0.236, 0.243, 0.488 and 0.486 mg/L as Boron), respectively.

The dissolved test item may have been one or several components of the test item. Given that toxicity cannot be attributed to a single component or mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

Validity criteria fulfilled:

yes

Remarks:

mortality in control was 0%; semi-static test conditions; oxygen content throughout the test was 9.3-10.1 mg O2/L

Conclusions:

The 96-hour LL50 (median Lethal Loading Rate) of the test item to rainbow trout based on nominal loading rates was greater than 100 mg/L loading rate WAF. The No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Executive summary:

Introduction

A study was performed to assess the acute toxicity of the test item to rainbow trout (Oncorhynchus mykiss). The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No 203, "Fish, Acute Toxicity Test" referenced as Method C.1 of Commission Regulation (EC) No. 440/2008.

 

Methods

Due to the low aqueous solubility and complex nature of the test item, for the purposes of testing the test item was prepared as a Water Accommodated fraction WAF). Following a preliminary range-finding test, seven fish were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/L for a period of 96 hours at a temperature of 13-15 °C under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L. Analysis of the test preparations at 0, 24, 72 and 96 hours gave measured concentrations of 11.2, 11.5, 23.2 and 23.1 mg/L (equivalent to 0.236, 0.243, 0.488 and 0.486 mg/L as Boron), respectively. Given that toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

 

Results

The 96-hour LL50 (median Lethal Loading Rate) of the test item to rainbow trout based on nominal loading rates was greater than 100 mg/L loading rate WAF. The No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Description of key information

The 96-hour LL50 (median Lethal Loading Rate) of the test item to rainbow trout based on nominal loading rates was greater than 100 mg/L loading rate WAF. The No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 100 mg/L

Additional information

A key study to assess the acute toxicity of the test item to rainbow trout (Oncorhynchus mykiss) was performed to OECD Guideline No 203. Due to the low aqueous solubility and complex nature of the test item, for the purposes of testing the test item was prepared as a Water Accommodated fraction WAF). Following a preliminary range-finding test, seven fish were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/L for a period of 96 hours at a temperature of 13-15 °C under semi-static test conditions. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L. The 96-hour LL50 (median Lethal Loading Rate) of the test item to rainbow trout based on nominal loading rates was greater than 100 mg/L loading rate WAF. The No Observed Effect Loading rate was 100 mg/L loading rate WAF.