Hexadecan- l-ol, ethoxylated

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Version / remarks:

2013

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: samples were taken from freshly prepared bulk test preparation on Days 0, 7, 14, 21, 28 and 31 and from the corresponding old or expired media on Days 1, 8, 15, 22, 29 and 32
- Sample storage conditions before analysis: stored frozen prior to analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a nominal amount of test item was weighed onto a glass slide and suspended under the surface of test water to give the 100 mg/L loading rate WAF. 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 to stand for 1-Hour. Visual 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. A 10 mL and a 2.0 mL pipette, covered at one end with Nescofilm, were submerged into the vessels (sealed end down to mid depth within the vessel). A length of Tygon tubing was attached to the 10 mL pipette and the Nescofilm was removed using the 2.0 mL pipette. A glass wool plug was inserted into the opposite end of the tubing and the WAF removed by mid depth siphoning (the first approximate 75 to 100 mL discarded) to give the 100 mg/L loading rate. Further filtration through a single sheet of filter paper was conducted to remove as much undissolved test item as possible. Microscopic observations of the WAF were performed after filtering and showed no micro dispersions of test item to be present.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnows
- Source: bred at testing facility
- Age at study initiation (mean and range, SD): newly fertilized eggs

Breeding
- Type and amount of food: combination of ZM small granular feed and frozen brine shrimp
- Feeding frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

130 to 150 mg/L as CaCO3 at test start
120 to 138 mg/L as CaCO3 at test termination

Test temperature:

24 - 26°C

pH:

7.8 - 8.7

Dissolved oxygen:

≥ 7.1 mg O2/L

Conductivity:

513 μS/cm at 20 °C

Nominal and measured concentrations:

Nominal loading rate: 100 mg/L WAF

Details on test conditions:

TEST SYSTEM
- Test vessel: 1 liter glass vessels were used from Day 0 to Day 15 and from Day 16 to the end of the test 5 liter glass vessels were used.
- Type (delete if not applicable): covered
- Fill volume: 400 mL from Day 0 to Day 6, 800 mL from Day 7 to Day 15 and 4000 mL from Day 16 to Day 32
- Aeration: aerated via narrow bore glass tubes from Day 8 onwards
- Renewal rate of test solution (frequency/flow rate): daily except for day 3 (in order to prevent premature hatching of the eggs)
- No. of organisms per vessel: 20 eggs
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours darkness
- Light intensity: 558 - 676 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The number of dead eggs (up to completion of hatching), dead and live larvae and sub-lethal effects of exposure were recorded daily.

RANGE-FINDING STUDY
- Test concentrations: 1.0, 10 and 100 mg/L loading rate WAF
- Results used to determine the conditions for the definitive study: The results showed there was no difference between the control and test concentrations of 1.0, 10 and 100 mg/L loading rate WAF in terms of hatching, survival and growth. A small number of underdeveloped fish were observed in the 1.0 and 10 mg/L loading rate WAF test groups between Days 5 and 11. A single fish in replicate R1 of the 1.0 mg/L loading rate WAF was observed to have a curved spine from Day 7 until test termination. These effects were considered to be due to natural variability as the effects seen were transient and were not loading rate specific.

Reference substance (positive control):

no

Duration:

32 d

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

loading rate WAF

Basis for effect:

other: Number Hatched, Post-hatch Survival, Body Length, Wet Weight

Details on results:

Please refer to the attached tables

Reported statistics and error estimates:

For the estimation of the No Observed Effect Loading Rate (NOEL) both the hatching and post-hatch survival data for the control and 100 mg/L loading rate WAF test group were compared using Fisher’s Exact Binomial Test. The length and wet weight data for the control and 100 mg/L loading rate WAF test group obtained on termination of the test were compared using a Student-t test incorporating Shapiro-Wilk’s Test on Normal Distribution and Levene’s Test on homogeneity of variance.

Table 1: Validity criteria for OECD 210.

Criterion from the guideline	Outcome	Validity criterion fulfilled
The dissolved oxygen concentration should be >60% of the air saturation value throughout the test.	81% ASV	yes
The water temperature should not differ by more than ± 1.5 °C between test chambers or between successive days at any time during the test, and should be within the temperature ranges specified for the test species (Annex 2).	Between test chambers: ± 1.0 °C Between successive days: ± 1.6 °C	A maximum temperature deviation between successive days of 1.6 °C was noted in replicates R1, R2and R4of the 100 mg/L loading rate WAF. This minor deviation to both the Study Plan and Test Guideline was considered to have had no adverse effect on the outcome or integrity of the test given that no adverse effects to exposure were observed in these replicates or the test group as a whole.
The analytical measure of the test concentrations is compulsory.
Overall survival of fertilised eggs and post-hatch success in the controls and, where relevant, in the solvent controls should be greater than or equal to the limits defined in Annex 2.	>90%	yes

Analysis of the fresh test preparations on Days 0, 7, 14, 21, 28 and 31 (seeAnnex 4) showed measured test concentrations to range from less than the limit of quantification (LOQ) of the analytical method employed, determined to be 0.0010 mg/L, to 0.18 mg/L. Measured test concentrations of less than the LOQ does not infer that no test item was in solution, just that any which was present was at a concentration below 0.0010 mg/L.

Analysis of the corresponding aged preparations on Days 1, 8, 15, 22, 29 and 32 showed measured test concentrations to range from less than the limit of detection (LOD) of the analytical method employed, determined to be 0.000025 mg/L, to 0.0080 mg/L indicating that the test item was unstable under the conditions of the test.

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.

For detailed information on biological and analytical results please refer to the attached tables.

Validity criteria fulfilled:

yes

Remarks:

Please refer to "any other information on results incl. tables"

Additional information

The chronic toxicity of Hexadecan-1-ol, ethoxylated to fish was investigated in a study following OECD guideline 210. The effects on the the early life stages of the Primephales promelas were assessed in a semi-static limit test with a daily renewal of the test solution. The fish were exposed to a test solution with a nominal loading rate of 100 mg/L (WAF). The test concentration was analytically monitored by HPLC/MS-MS. During the 32-day test period the number of dead eggs, the death of larvae and juvenile fish were recorded daily. At the end of the test, the length and wet weight of each surviving fish was determined. No significant effects on the hatching rate, post-hatch survival or fish body length and weight were observed. The determined NOELR (32 d) was > 100 mg/L (nominal, WAF).

Studies investigating the acute and chronic toxicity of the category substance Alcohols, C16-18 (even numbered), ethoxylated, < 2.5 EO (CAS No. 68439-49-6) are still ongoing. The outcome of the studies is expected to have an impact on the evaluation of the aquatic toxicity of Hexadecan-1-ol, ethoxylated.

Therefore, the current assessment of the aquatic toxicity of the target substance Hexadecan-1-ol, ethoxylated is considered preliminary and will be updated as soon as the final study reports are available.