Diundecyl phthalate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Under flow through conditions, daphnids were exposed to a range of concentrations for 21 days.
- Parameters analysed / observed: The number of live offspring /surviving parent was assessed.

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Two of four replicate of test solutions and control water were analyzed on days 0, 7, 14, and 21. In addition, two quality-assurance samples were prepared on each sample collection day and remained with the set of samples through the extraction and analysis procedures. These two samples were prepared in test water or media, with one of the samples prepared at a concentration unknown to the analyst. Each sample (100 to 300 ml) was collected from the midpoint of the test chamber with a pipette and transferred to a 500-ml separatory funnel.

- Sample storage conditions before analysis: sample extracts were stored in a 10-ml serum vial at 0ºC until the analysis was performed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: No data on preparation of test solution. A gas-tight syringe with a mechanical injector was used to introduce a desired amount of test chemical directly into the chemical mixing chamber of the diluter with each diluter cycle.
- Controls: dilution water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): N/A
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: waterflea
- Strain/clone: Not reported
- Justification for species other than prescribed by test guideline: N/A
- Source: In house culture
- Age of parental stock (mean and range, SD): < 24h old
- Feeding during test
- Food type: A mixture of unicellular green algae and Rangen Salmon Starter fish food
- Amount: 2.0 ml of a salmon starter solution containing 5.0 mg/ml and 2.0 ml of an algal suspension (Selenastrum sp., Ankistrodesmus sp., and Chlamydomonas sp. at concentrations of 1 x 10^7 to 5.0 x 10^7, each)
- Frequency: three times a day during weekdays and twice daily on weekends and holidays.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

None

Hardness:

150 to 180 mg/L (as CaC03)

Test temperature:

21 ± 2ºC

pH:

7.9 to 8.3

Dissolved oxygen:

>60% of saturation

Conductivity:

400 to 600 µmho/cm

Nominal and measured concentrations:

Mean measured concentrations: 0.000, 0.004, 0.008, 0.014, 0.028 and 0.059 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass battery jars
- Material, size, headspace, fill volume: 1.75-L
- Aeration: No data
- Type of flow-through (e.g. peristaltic or proportional diluter): modified proportional diluter with a 0.5 dilution factor, similar to those described by Mount and Brungs (Mount, D.I. and W.A. Brungs. 1967).
- Renewal rate of test solution (frequency/flow rate): 4.4-5.0 aquarium volume replacements /24h
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Fortified well water
- Alkalinity: 100 to 130 mg/L CaCO3
- Conductivity: 400 to 600 µmho/cm
- Culture medium different from test medium: No
- Intervals of water quality measurement: Dissolved oxygen concentrations and temperature of the test solutions were monitored every weekday within one replicate test chamber of each treatment level and control. Total hardness, alkalinity, specific conductance, and pH of the test solutions were monitored weekly in one test vessel from each treatment and control.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16:8h light:dark
- Light intensity: 2-4 hectolux (2.94 to 5.88 W/m2) at the solutions surface daily.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): survival and reproduction (cumulative number of offspring per live adult). Both adult survival and offspring production by the daphnids were assessed every weekday, except holidays, from day 7 through day 21.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.059 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.059 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Results with reference substance (positive control):

N/A

Table 1. Summary of survival and reproductive data for the daphnia magna chronic study with diundecyl phthalate

Mean measured concentration (mg/L)	% survival on day 21 (SD)	Mean offspring/female a
0.059	98 (3) b	92 (6)
0.028	100 (0)	98 (26)
0.014	100 (0)	89 (2)
0.008	100 (0)	90 (4)
0.004	96 (8)	87 (15)
control	99 (2)	90 (10)

a Mean cumulative number of offspring per living female on day 21.

bThe standard deviation (SD) is in parentheses.

c NS = no survivors on day 21.

*Denotes significant statistical difference ( p = 0.05) from the control.

Table 2. Results of Daphnia magna chronic toxicity study with diundecyl phthalate

Test material	Solubility observations	Highest mean measured concn.	Chronic effects (mg(L)				Most sensitive end point
			LOEC	NOEC	MATCa
DUP	NVF/OS	0.059	- b	0.059	- b	- b

NVF = no visible film on surface of test solution; 0S = test organisms on surface at LOEC; FOX = film observed on surface at LOEC;

LOEC = lowest-observed-effect concentration; NOEC = no-observed-effect concentration;

MATC = geometric MATC = (LOEC x NOEC)1/2; S = survival; R = reproduction.

a Geometric mean maximum acceptable toxicant concentration.

b No effects observed on either survival or reproduction at all test concentrations.

Validity criteria fulfilled:

yes

Conclusions:

In a long-term aquatic toxicity test to daphnia magna conducted in flow-through conditions, the NOEC of the test substance was determined to be 0.059 mg/L as no effects were observed at any concentration tested.

Executive summary:

A 21-d Daphnia magna chronic study was performed with diundecyl phthalate. The study was performed in flow-through conditions with concentrations of 0.004, 0.008, 0.014, 0.028 and 0.059 mg/L (mean measured) and a diluent water control. Four replicate test chambers with 20 daphnids each (<24 h) were used for each test concentration. A validated analytical method based on gas chromatography was used to monitor two of four replicates of test solutions and control water on days 0, 7, 14, and 21. No effects were observed on either survival or reproduction at all test concentrations. Based on these results, the NOEC, based on the mean measured concentration, was 0.059 mg/L, the highest concentration investigated and regarded as the maximum water solubility under the test conditions.

Description of key information

Key study: 21-d Daphnia magna chronic study. The NOEC of DUP was determined to be 0.059 mg/L, the highest concentration investigated and regarded as the maximum water solubility under the test conditions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.059 mg/L

Additional information

Key study: A 21-d Daphnia magna chronic study was performed with diundecyl phthalate. The study was performed in flow-through conditions with concentrations of 0.004, 0.008, 0.014, 0.028 and 0.059 mg/L (mean measured) and a diluent water control. Four replicate test chambers with 20 daphnids each (<24 h) were used for each test concentration. A validated analytical method based on gas chromatography was used to monitor two of four replicates of test solutions and control water on days 0, 7, 14, and 21. No effects were observed on either survival or reproduction at all test concentrations. Based on these results, the NOEC, based on the mean measured concentration, was 0.059 mg/L, the highest concentration investigated and regarded as the maximum water solubility under the test conditions.