Propane-1,2-diyl dibenzoate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study is classified as reliable with restrictions because it is an acceptable and reliable study carried out by USEPA (Q)SAR ECOSAR (v1.11). The result is calculated data as modelled by EPISUITE. Meets generally accepted scientific principles, acceptable for assessment.

Justification for type of information:

QSAR prediction

Guideline:

other: REACH guidance on QSARs R.6, May/July 2008

Principles of method if other than guideline:

The structure-activity relationships (SARs) presented in ECOSAR are used to predict the aquatic toxicity of chemicals based on their similarity of structure to chemicals for which the aquatic toxicity has been previously measured. Most SAR calculations in the ECOSAR Class Program are based upon the octanol/water partition coefficient (Kow). SARs are developed for chemical classes based on measured test data that have been submitted by industry or they are developed by other sources for chemicals with similar structures, e.g., phenols. Using the measured aquatic toxicity values and estimated Kow values, regression equations can be developed for a class of chemicals. Toxicity values for new chemicals may then be calculated by inserting the estimated Kow into the regression equation and correcting the resultant value for the molecular weight of the compound.

GLP compliance:

no

Remarks:

QSAR

Test organisms (species):

other: Fish

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3.7 mg/L

Conc. based on:

test mat.

Remarks on result:

other: This value is predicted for the Esters class

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

6.5 mg/L

Conc. based on:

test mat.

Remarks on result:

other: This value is predicted for Neutral Organic SAR (baseline toxicity)

Conclusions:

Based on the prediction results described, propylene glycol dibenzoate was predicted to have a fish LC50 of 3.7 mg/L after 96 hours exposure (ester class toxicity).

Executive summary:

Based on the prediction results described, propylene glycol dibenzoate was predicted to have a fish LC₅₀ of 3.7 mg/L after 96 hours exposure (ester class toxicity).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 October 1999 - 30 October 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in accordance with EC, OECD, and US EPA test guidelines, and in compliance with GLP.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

yes

Remarks:

Not thought to have effected the integrity of the study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

Not thought to have effected the integrity of the study.

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1400 (Fish Acute Toxicity Test)

Deviations:

yes

Remarks:

Not thought to have effected the integrity of the study.

Principles of method if other than guideline:

Protocol deviations

The fish were not fed for 24 hours before the start of the test, not 48 hours as specified by the protocol. However, the test vessels were inspected regularly each day for fecal material and this was removed when found. This deviation is not considered to have increased the microbial loading as measured levels of the test substance were maintained between 88 to 104% of their nominal values after 24 hours, when the majority of faecal material was produced.

Microbial counts were performed at 24, 48 and 72 hours in addition to the 0 and 96 hour counts specified in the protocol, at the request ofthe sponsor.

Microbial counts were not made for the control vessels, as this was not considered necessary. Counts from the solvent control and test levels only were deemed sufficient for comparative purposes.

The flow rate of the diluent was reduced from 280 mL/min as stated in the protocol to 260 mL/min during the definitive test in order to maintain the ratio of solvent to diluent.

The above deviations were not thought to have affected the integrity ofthe study.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 0.25, 0.55, 1.2, 2.7, and 5.8 mg/L.
- Sampling method: Samples (50 mL) of media were taken from the control and each test concentration daily for chemical analysis. Samples (10 mL) were also taken for determination of bacterial count Samples were taken at 0, 24, 48, 72 and 96 hours.
- Sample storage conditions before analysis: Not specified.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Dynamic exposure conditions were used. Dipropylene glycol dibenzoate has poor water solubility and had been shown to rapidly degrade in other aquatic studies. The test substance was dissolved in dimethyl formamide to give a series of stock solutions at 2.5, 5.5, 12, 27 and 58 mg/L DPGDB. The stock solutions were dispensed automatically by dosing apparatus into the flowing test water.
- Eluate: The water used for the study was laboratory tap water filtered dechlorinated and softened by passage through an Elga water purification system
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): dimethyl formamide (DMF)
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 100 µL DMF/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None

The test and mixing vessels were changed daily to maintain the cleanliness of the test system. The vessels were removed every day and replaced with clean dry tanks. Used tanks were washed with detergent, rinsed with acetone, then acid-washed and rinsed with water. The tanks were allowed to dry before re-use

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Strain: Pimephales promelas
- Source: Aquatic Research Organisms Hampton New Hampshire USA
- Length at study initiation (length definition, mean, range and SD): At this time the fish were measured from the head to the caudle peduncle (standard length). The mean standard length of the sample was 2.7 cm (SD = 0.14 cm) The EC guideline specifies a lower size limit of 3.0 cm total length. In order to confirm that the stock fish were within this limit a second sample of fish from the same stock tank were measured after the definitive test. The mean standard length of this sub sample was 25 cm (SD=0.14 cm) and the mean total length head to tip of caudal fin was 31 cm (SD 0.16 cm). As the mean standard lengths of both batches of fish from the stock tank were similar it can be assumed that the total length of the fish used for the definitive test was greater than 3 cm.
- Weight at study initiation (mean and range, SD): Mean weight was 0.28 g (SD = 0.04 g)
- Feeding during test
No feeding during the 24 hour period before the start of the exposure period, or during the exposure period.


ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not):Temperature remained within the range 17 to 18°C in the 14 day period immediately before the study and at 18°C in the seven day period before the study.
- Type and amount of food: The fish were fed daily to repletion with Tetramin flakes.
- Feeding frequency: Food was not given during the 24 hour period immediately before exposure or during the exposure period itself
- Health during acclimation (any mortality observed): no

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

During acclimation , hardness, measured as mg/L CaCO3 varied between 127 and 162. During the exposure period it varied between 133 and 164 mg/L CaCO3.

Test temperature:

23 to 24°C

pH:

7.9 to 8.1

Dissolved oxygen:

6.8 to 7.9 mg O2 / L

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.25, 0.55, 1.2, 2.7 and 5.8 mg/L
Mean measured concentrations: 0.25, 0.53, 1.2, 2.6 and 4.9 mg/L
Expressed as % of nominal concentration: 100, 96, 100, 97, 84%

Due to the nature of the study design the concentrations of dipropylene glycol monobenzoate were not determined in this study

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquarium
- Type: open 20 litre mixing vessel
- Aeration: No
- Type of flow-through (e.g. peristaltic or proportional diluter): peristaltic pump.
- Renewal rate of test solution (frequency/flow rate): 260 ml/min
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2
- Biomass loading rate:


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water filtered, dechlorinated and softened by passage through an Elga water purification system.
- Total organic carbon: C 1.1 mg/L
- Chlorine: <0.1 mg/L
- Alkalinity: as CaCO3, 98 mg/L
- Ca/mg ratio: 53/3.2 = 10.19
- Conductivity: 420 µS/cm


OTHER TEST CONDITIONS
- Photoperiod: 16 hours light / 8 hours dark


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The criteria of death employed in this study were i) absence of respiratory movement and ii) absence of response to physical stimulation of the caudal peduncle. In addition to observations on mortality at 0.25, 3, 6, 24, 48, 72 and 96 hours subjective assessments were made on the incidence and type of sub lethal effects compared with control fish.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2-fold
- Range finding study
- Test concentrations: A preliminary study was performed with initial concentrations of test substance of 4.0 and 6.0 mg/L.
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL 3.2 - 4.3

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: None reported
- Other biological observations: Inflammation of the gills and loss of equilibrium were noticed after two days exposure at 4.9 mg/L, and after 4 days at 2.6 mg/L. Fish exposed to 4.9 mg/L showed a curved body shape caused by muscle rigidity, and lesions were visible one one fish at this level
- Mortality of control: None

Conclusions:

The 96 hour LC50 value for dipropyleneglycol dibenzoate with fathead minnow was 3.7 mg/L. The "no-observed effect concentration" (NOEC) was 1.2 mg/L
Measured concentrations of DPGDB correlated well with the nominal concentrations.

Executive summary:

Key data is available for propylene glycol dibenzoate (PGDB). This data is supported by relevant information available from a structural analogue Dipropylene glycol dibenzoate (DPGDB). The justification for read across is presented as an attachment included in Section 13 of the IUCLID dossier.

A study was performed to determine the acute toxicity of the test material DPGDB to fathead minnows. The study was conducted according to EC, OECD, and US EPA test guidelines, and in compliance with GLP.

Groups of 20 fish (duplicate groups of ten fish per group) were exposed to nominal dose levels 0, (control), 0.25, 0.55, 1.2, 2.7, and 5.8 mg/L DPGDB over a period of 96 hours using a dynamic exposure system.

The 96 h LC₅₀ value for DPGDB with fathead minnow was 3.7 mg/L based upon mean measured concentrations. The "no-observed effect concentration" (NOEC) for DPGDB with fathead minnow was 1.2 mg/L.

Description of key information

Key data is available for propylene glycol dibenzoate (PGDB). This data is supported by relevant information available from a structural analogue Dipropylene glycol dibenzoate (DPGDB). The justification for read across is provided as an attachment included in Section 13 of the IUCLID dossier.

Propylene glycol dibenzoate is predicted to have fish LC₅₀s of 3.699 mg/L and 6.492 mg/L after 96 hours exposure to fish for the Ester class and the baseline toxicity, respectively (US EPA, 2012; Klimisch score = 2).

The 96 h LC₅₀ value for Dipropylene glycol dibenzoate with the fathead minnow was determined to be 3.7 mg/L. The "no-observed effect concentration" (NOEC) with the fathead minnow was determined to be 1.2 mg/L (Huntingdon Life Sciences, 2000a; Klimisch score = 1).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

3.699 mg/L

Additional information

Key data is available for propylene glycol dibenzoate (PGDB). This data is supported by relevant information available from a structural analogue Dipropylene glycol dibenzoate (DPGDB). The justification for read across is provided as an attachment included in Section 13 of the IUCLID dossier.

Based on the prediction results, propylene glycol dibenzoate was predicted to have a fish LC₅₀ of 3.7 mg/L after 96 hours exposure (ester class toxicity)

(US EPA, 2012; Klimisch Score = 2).

Studies were conducted to determine the acute toxicity of the test material DPGDB to freshwater fish (Rainbow Trout and fathead minnows). Studies with both species were conducted with the substance introduced using a water accommodated fraction (WAF) and by flow through. The studies were conducted according to EC, OECD, and US EPA test guidelines, and in compliance with GLP. The WAF studies suffered from low concentrations of the test substance being measured in the initial WAF solution and subsequent losses of the test substance. In addition, the results from the WAF tests with the two species showed no toxicity with one species and high toxicity with the other which was unexplainable. Because of the various problems with the two WAF tests, they are believed to be unreliable and have been disregarded. The flow through studies were well conducted exhibiting constant exposure levels throughout the studies and the results from both species were similar and in line with QSAR estimations. The results from the flow through studies are being used for the hazard determination and are presented below.

The 96 h LC₅₀ value for DPGDB with fathead minnow was determined 3.7 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with fathead minnow was determined to be 1.2 mg/L (Huntingdon Life Sciences, 2000a; Klimisch score = 1).

The 96 h LC₅₀ value for DPGDB with rainbow trout was >3.0 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with rainbow trout was 3.0 mg/L (Huntingdon Life Sciences, 2000b; Klimisch score = 1).

These values are supported by the QSAR modelling (US EPA, 2009; Klimisch score = 2) with a 96-hour LC₅₀ value of 3.94 mg/L for DPGDB.