Formaldehyde, oligomeric reaction products with 4,4'-isopropylidenediphenol and diethylenetriamine

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

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

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

A nominal amount of test item (22 mg) was added to the surface of 22 liters of test water to give the 1.0 mg/L loading rate. After the addition of the test item, the test 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 settling for 1 hour. At 0 hours, microscopic observation of the WAF indicated that there was not undissolved test item present. At 24 hours, visual inspection of the WAF indicated that 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) as a precaution. A glass wool plug was also used as a precautionary measure at 48 and 72 hours. 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 1.0 mg/L loading rate WAF. Microscopic observations of the WAF was performed after filtering and no test item was observed.

The concentration and stability of the test item in the test preparations were verified by chemical analysis in fresh test preparations at 0 and 72 hours, and in aged test solutions at 24 and 96 hours

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

14 degrees Celcius

pH:

7.3-7.7

Dissolved oxygen:

9.6-11.6

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test item to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated using the threshold approach and gave a 96-Hour LL50 value of greater than 1.0 mg/L loading rate WAF. The No Observed Effect Loading rate was 1.0 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 the test, the test medium was prepared as a Water Accommodated Fraction (WAF).

In accordance with the recommendations of REACh, the test was conducted according to the threshold approach recommended by ECHA. Using this approach the lowest EL50 value from either the Algal Growth Inhibition study or Acute Toxicity to Daphnia magna study is set as the threshold loading rate and a “Limit test” is conducted at this threshold loading rate. If no mortalities are observed this indicates that fish are not the most sensitive species and that the LL50 is greater than the threshold loading rate. The EL50 value obtained from the Algal Growth Inhibition study (Envigo Study Number RX71QY) was the lower of these two EL50 values, and hence the test was conducted at a single loading rate of 1.0 mg/L.

Seven fish were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 1.0 mg/L for a period of 96 hours at a temperature of 14 °C to 15 ºC under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 1, 3 and 6 hours after the start of exposure, and then daily throughout the test until termination after 96 hours.

Results

Chemical analysis of the fresh test preparations at 0 and 72 hours showed measured test concentrations of 0.974 and 0.646 mg/L, respectively. Chemical analysis of the aged test preparations at 24 and 96 hours showed measured test concentrations of 0.936 and 0.613 mg/L, respectively.

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 nominal loading rates only.

Exposure of rainbow trout to the test item gave LL50 values of greater than 1.0 mg/L loading rate WAF. The No Observed Effect Loading Rate was 1.0 mg/L loading rate WAF.

Description of key information

The acute toxicity of the test item to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated using the threshold approach and gave a 96-Hour LL50 value of greater than 1.0 mg/L loading rate WAF. The No Observed Effect Loading rate was 1.0 mg/L loading rate WAF.