Reaction product of 3,5,5-trimethyl-hexanoic acid and 2-methylpropanoic acid and pentaerythritol

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 April - 11 September 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study conducted in accordance with International guidelines and GLP. Analysis from Day 21-28 provides a snapshot of bioaccumulation potential but is acceptable to conclude on endpoint. Aged test medium was found to be ca. 10 % of nominal with no explanantion (i.e. adsorption to glassware, degradation). Test item concentrations in the test medium were not maintained ±20 % of the mean value through the testing period.

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 B (Bioaccumulation: Semi-static Fish Test)

Version / remarks:

12 May 1981

Deviations:

yes

Remarks:

Test item concentrations in the test medium were not maintained ±20 % of the mean value through the testing period.

GLP compliance:

yes

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature, in the dark and under nitrogen.
- Stability under test conditions: Assumed stable.
- Solubility and stability of the test substance in the solvent/vehicle: Soluble and stable in acetone at 15 mg/mL (stock).
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: Stable for 48 h in test media

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: N/A, applied as supplied.
- Preliminary purification step (if any): N/A
- Final dilution of a dissolved solid, stock liquid or gel: N/A
- Final preparation of a solid: N/A

FORM AS APPLIED IN THE TEST (if different from that of starting material): Applied as supplied.

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable): N/A

OTHER SPECIFICS: No

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: Day 0, 22, 23, 24, 25, 26, 27 and 28.
- Sampling intervals/frequency for test medium samples: As per fish.
- Sample storage conditions before analysis: Analysed on same day as sampling otherwise media samples stored at low temperature and/or fish samples frozen.
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):

On each occasion, 500 mL water and 10 fish were sampled (all remaining fish sampled on Day 28). Water samples were diluted with acetonitrile then filtered through a 0.22 µm filter prior to LC-MS analysis. Fish samples were homogenised. 1 g of the homogenate was added to a 150 mL conical flask and 50 mL acetonitrile added. The mixture was shaked thoroughly. After standing for 30 mins the samples were placed on an oscillating shaker for 30 mins. The extract was filtered and the resulting residue re-suspended in 5 mL of acetonitrile. The extract was dried by rotary evaporation and the resulting residue re-suspended in 10 mL acetonitrile and filtered prior to LC-MS analysis.

Vehicle:

yes

Remarks:

Acetone

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 1.5 mg/mL acetone stock solution was added to 50 L of test media which was subsequently stirred (30 mins) and aerated (overnight) prior to addition of fish.
- Controls: Solvent controk tank prepared.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) at different concentrations and in control(s)): Not reported
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Not reported

PREPARATION OF SPIKED FISH FOOD
- Details on fish food (source, fat content as supplied, etc): Not reported
- Details of spiking (e.g. i) liquid test material (neat); ii) with a vehicle (corn or fish oil); or iii) using an organic solvent: Acetone solution spiked into 50 L test media.
- Quantity of corn or fish oil vehicle, if used, per unit mass of fish food: N/A
- Chemical name of vehicle (organic solvent), if used: Acetone
- Method of mixing: Overhead stirrer
- Equilibration time: Test solution prepared the night before exposure.
- Method for removal of solvent, if used: N/A

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra fish
- Strain: Danio rerio (previously Brachydanio rerio)
- Source: Not reported
- Age at study initiation (mean and range, SD): Not reported
- Length at study initiation (length definition, mean, range and SD): 25 - 35 mm
- Weight at study initiation (mean and range, SD): 0.2 - 0.4 g
- Weight at termination (mean and range, SD):
- Method of breeding: N/A
- Lipid content at test initiation (mean and range, SD): Not determined
- Health status: 0 mortalities through test period
- Description of housing/holding area: Not reported
- Feeding during test
- Food type: Not reported
- Amount: Not reported
- Frequency: Daily

ACCLIMATION
- Acclimation period: 2 weeks
- Acclimation conditions (same as test or not): As per test conditions
- Type and amount of food: Not reported
- Feeding frequency: "Normal diet"
- Health during acclimation (any mortality observed): Free from observable disease.

Route of exposure:

aqueous

Justification for method:

aqueous exposure method used for following reason:

Test type:

semi-static

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

Not conducted

Test temperature:

22.3 - 23.7 ºC

pH:

6.90 - 8.18

Dissolved oxygen:

60.2 - 101.7

TOC:

Not conducted

Salinity:

Not conducted

Conductivity:

Not conducted

Details on test conditions:

TEST SYSTEM
- Test vessel: Fish tank - details not reported
- Type (delete if not applicable): Not reported
- Material, size, headspace, fill volume: Filled to 50 L.
- Aeration: Test solution aerated overnight prior to fish exposure.
- Type of flow-through (e.g. peristaltic or proportional diluter): N/A
- Renewal rate of test solution (frequency/flow rate): Fresh test solutions prepared on Day 0, 1, 2, 7, 14, 21 and 27.
- No. of organisms per vessel: 80
- No. of vessels per concentration (replicates): 2
- No. of vessels per control / vehicle control (replicates): 1
- Biomass loading rate: Not reported

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Filtered tap water
- Particulate matter: Not reported
- Metals: Not reported
- Pesticides: Not reported
- Chlorine: Not reported
- Alkalinity: Not reported
- Ca/mg ratio: Not reported
- Conductance: Not reported
- Holding medium different from test medium: No
- Intervals of water quality measurement: Day 0, 22 - 28
- Intervals of test medium replacement: Day 0, 1, 2, 7, 14, 21 and 27

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Not reported
- Light intensity: Not reported

RANGE-FINDING / PRELIMINARY STUDY
- Based on the preliminary test (G1244J001A), the 96 h LC50 of Test item in zebra fish was > 1.8 mg/L.

Nominal and measured concentrations:

1.5 and 0.15 mg/L

Reference substance (positive control):

not required

Details on estimation of bioconcentration:

28 d BCF (BCF28) was calculated from the following equation;

BCF28 = Cf28 / Cw28

where;
Cf28: 28th day concentration in fish (mg/kg)
Cw28: 28th day concentration in test medium (mg/L)

Remarks on result:

not measured/tested

Key result

Conc. / dose:

>= 0.15 - <= 1.5 mg/L

Temp.:

>= 20 - <= 25 °C

pH:

7

Type:

BCF

Value:

>= 0.179 - <= 14.45 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other:

Remarks:

Results pertain to 1 component of the test item

Remarks on result:

not measured/tested

Remarks on result:

not measured/tested

Details on kinetic parameters:

N/A

Metabolites:

N/A

Results with reference substance (positive control):

N/A

Details on results:

- Mortality of test organisms: 0 mortalities during test period.
- Behavioural abnormalities: None
- Observations on feeding behavior: None
- Observations on body length and weight: None
- Reproduction during test period: N/A
- Other biological observations: No
- Organ specific bioaccumulation: N/A - whole tissue assessment conducted.
- Bound residues forming a plateau: N/A
- Mortality and/or behavioural abnormalities of control: No
- Loss of test substance during test period: Yes, aged solutions were measured and found to be 10 % of nominal after 24 h. Without significant uptake by fish the test item may have degraded or adsobed to the apparatus.
- Non-eliminated residues (NER) at the end of elimination phase: N/A, depuration phase not conducted

Table 1       Concentration of component 1 in Tetraesters of pentaerythritol with 2- methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid in aged test media

 

Time (Day)	Analysed Concentrations (mg/L)
	Control	0.15 mg/L Rep A	0.15 mg/L Rep B	1.5 mg/L Rep A	1.5 mg/L Rep B
22	nd	0.0108	0.0102	0.0800	0.0810
23	nd	0.0105	0.00943	0.0859	0.0939
24	nd	0.0137	0.0098	0.0957	0.0983
25	nd	0.0124	0.0123	0.127	0.119
26	nd	0.0159	0.0141	0.140	0.143
27	nd	0.0129	0.0133	0.134	0.133
28	nd	0.0154	0.0165	0.130	0.135

 

Table 2       Concentration of component 1 in Tetraesters of pentaerythritol with 2- methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid in aged test media

 

Time (Day)	Analysed Concentrations (mg/L)
	Control	0.15 mg/L Rep A	0.15 mg/L Rep B	1.5 mg/L Rep A	1.5 mg/L Rep B
22	nd	0.0119	0.00422	0.135	0.297
23	nd	0.0142	0.0137	0.236	0.250
24	nd	0.00721	0.00990	0.731	1.420
25	nd	0.00671	0.00591	0.454	0.456
26	nd	0.00285	0.00941	0.184	0.410
27	nd	0.00265	0.00276	0.311	0.126
28	nd	0.00814	0.00665	0.175	0.203

 

Table 3       BCF values

 

Time (Day)	Analysed Concentrations (mg/L)
	0.15 mg/L Rep A	0.15 mg/L Rep B	1.5 mg/L Rep A	1.5 mg/L Rep B
22	1.102	0.414	1.688	3.667
23	1.352	1.453	2.747	2.662
24	0.526	1.010	7.638	14.45
25	0.541	0.480	3.575	3.832
26	0.179	0.667	1.314	2.867
27	0.205	0.208	2.321	0.947
28	0.529	0.403	1.346	1.504
Mean BCF	0.648		3.611

Validity criteria fulfilled:

no

Remarks:

Test item concentrations in the test medium were not maintained ±20 % of the mean value through the testing period.

Conclusions:

The BCF of component 1 in Tetraesters of pentaerythritol with 2-methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid in zebra fish was determined to be within the range of 0.179 - 14.45.

Executive summary:

OECD 305B (2013) – One component of the UVCB Tetraesters of pentaerythritol with 2-methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid was used to determine the bioconcentration factor (BCF) in zebra fish (Danio rerio). The test concentrations, 0.15 and 1.5 mg/L, were chosen based on the water solubility data of component 1 (2.5 mg/L; OECD 105; Sydney, P.(2012)) and also its LC₅₀to fish (>1.8 mg/L; OECD 203; Matsuura, T.(2011)). In addition, an untreated solvent (acetone) control test group was also prepared and run in parallel with the treated test groups.

 

The test medium was maintained at 20 ± 2 ºC with dissolved oxygen saturation values of >60 %.

 

Fresh treatment solutions were prepared and renewed on a daily basis. Water and fish samples were collected for analysis on Day 0 and Days 22-28. Water samples and whole fish homogenate extracts were analysed by LC-MS to determine the concentration of component 1 in the samples at each of the sampling intervals.

 

The bioaccumulation factor was calculated using the following equation;

 

BCF = C_f/ C_w

where;

C_f= concentration of component 1 in fish

C_w= concentration of component 1 in test solution

 

The bioconcentration factor (BCF) of component 1 was determined to be in the range of 0.179 – 14.45. With a BCF of < 2000, component 1 of Tetraesters of pentaerythritol with 2- methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid was not bioaccumulative under the conditions of this test.

Description of key information

BCF: 14.45; OECD 305B; Ying, L (2013)

Key value for chemical safety assessment

BCF (aquatic species):

14.45 dimensionless

Additional information

With a BCF of < 2000, component 1 of Tetraesters of pentaerythritol with 2-methylpropanoic acid and 3,5,5-trimethyl-hexanoic acid was not bioaccumulative under the conditions of this test. The study was conducted in accordance with International guidelines and GLP and is sufficient to conclude on the endpoint.