2-tetradecyloxirane, reaction products with boric acid

Endpoint summary

Description of key information

Short-term toxicity to fish: 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

 

Short-term toxicity to aquatic invertebrates: The 48-hour EL50 (Median Effective Loading Rate) for the test item to Daphnia magna 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.

Long-term toxicity to fish: The 33-day LL50 (median Lethal Loading Rate) of the test item to fathead minnow based on nominal loading rates was greater than 100 mg/L loading rate WAF for hatching and post-hatch survival. The 33-day EL50 (Effective Loading Rate) of the test item to fathead minnow 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

Long-term toxicity to aquatic invertebrates: The 21-Day EL50 (reproduction) value based on nominal test concentrations was calculated to be 23 mg/L loading rate WAF. The LOEL and the NOEL based on nominal loading rates were 32 and 10 mg/L respectively

 

Algae: Exposure of Pseudokirchneriella subcapitata to the test item gave EL*50 values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

 

Microorganisms: The EC 50 (3h) for sewage sludge respiration inhibition is > 10000 mg/L.

Additional information

Short-term toxicity to fish

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.

 

Short-term toxicity to aquatic invertebrates (Daphnia)

A key study to assess the acute toxicity of the test item to Daphnia magna was performed in accordance with OECD Guideline No 202. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to a Water Accommodated Fraction (WAF) of the test item at single nominal loading rate of 100 mg/L for 48 hours at a temperature of 21-22 °C under static test conditions. The number of immobilized Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hours. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L loading rate WAF. The 48-hour EL50 (Median Effective Loading Rate) for the test item to Daphnia magna 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.

Long-term toxicity to fish

A key study was performed to assess the effects of the test item on newly hatched larvae of the fathead minnow (Pimephales promelas). The method followed that described in the OECD Guidelines for Testing of Chemicals (2013) No 210, "Fish, Early-Life Stage Toxicity Test. Due to the low aqueous solubility and complex nature of the test item for the purposes of the test the test item was prepared as a Water Accommodated Fraction (WAF). Based on the results of a preliminary range-finding test, newly fertilized fathead minnow eggs (4 replicates of 20 eggs per group) were exposed to a WAF of the test item for a period of 33 days at a temperature of 23 ºC to 27 °C under semi-static test conditions. The test solutions were renewed three times per week throughout the test. The test item solution was prepared by stirring a nominal loading rate of test item (100 mg/L) in test water using a 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 approximately 1 hour. Microscopic inspection of 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 dispersed material by filtering the WAF through a glass wool plug (2 to 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 to 100 mL discarded). Microscopic observation of the WAF was performed after filtering and showed no micro-dispersions of test item to be present. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were recorded daily until termination of the test (28 days post-hatch). At test termination the length and wet weight of the surviving fish were measured.

 

Chemical analysis of the test preparations was conducted using ICP-MS analysis for the presence of boron. Analysis of the fresh test preparations on Days 0, 5, 9, 14, 19, 26 and 30 showed measured boron concentrations to be between 0.210 and 0.362 mg/L (equating to total test item concentrations of 10.7 mg/L to 18.3 mg/L). Analysis of the old test preparations on Days 2, 7, 12, 16, 21, 28 and 33 showed measured boron concentrations of between 0.201 and 0.414 mg/L (equating to total test item concentrations of 10.2 to 21.0 mg/L) were obtained. Therefore, given that the 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 the nominal loading rate. The application of the test item to newly fertilized eggs of fathead minnows was considered to have no effect on the survival or growth of the larvae. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

Long-term toxicity to aquatic invertebrates (Daphnia)

A key study to assess the effect of the test material on the reproduction of Daphnia magna over a 21-day period was performed to OECD Guideline No 211. Based on the results of a preliminary range-finding test, Daphnia magna were exposed (10 replicates of a single daphnid per group) to a Water Accommodated Fraction (WAF) of the test material over a range of loading rates of 1.0, 3.2, 10, 32 and 100 mg/L for a period of 21 days. The WAFs were renewed 3 times per week. The numbers of live and dead adult Daphnia and young daphnids (live and dead) were determined daily. The Daphnia were fed daily with an algal suspension. Under the test conditions, exposure of Daphnia magna to the test material resulted in significant mortalities at the loading rates of 32 and 100 mg/L resulting in 80% and 100% mortalities by Day 21 respectively. The 7, 14 and 21-Day EL50 (immobilisation) values, based on nominal loading rates, for the parental Daphnia generation (P1) were calculated to be 44 (26-83), 31 (19-50) and 20 (13-31) mg/L loading rate WAF, respectively. A significant impairment of reproduction was observed at the 32 mg/L loading rate WAF test group after 21 days. The 21-Day EL50 (reproduction) value based on nominal test concentrations was calculated to be 23 (17-30) mg/L loading rate WAF. The LOEL and the NOEL based on nominal loading rates were 32 and 10 mg/L respectively.

 

Algae

In a key study performed to OECD 201 and EC Method C.3 Pseudokirchneriella subcapitata was exposed to a WAF of the test item at a single nominal loading rate of 100 mg/L (six replicate flasks) for 72 hours, under constant illumination and shaking at a temperature of 24 ±1°C. Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group using a Coulter Multisizer Particle Counter. Exposure of Pseudokirchneriella subcapitata to the test item gave EL*50 values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L

Inhibition of sewage sludge micro-organisms

The key study was performed in accordance with OECD Guideline 209. The study assessed the potential for the test substance to inhibit aerobic microbial metabolism, as indicted by the consumption of oxygen. The test duration was a three-hour exposure period to the test material at five nominal dose concentrations (1, 10 , 100, 1000 and 10000 mg/L) followed by up to ten minutes for the measurement of oxygen consumption. A duplicate control group and a positive control using a reference toxicant, 3,5 -dichlorophenol were run simultaneously with the test group. The EC50 was calculated to be greater than 10000 mg/L.