Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
short-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:
comparable to guideline study with acceptable restrictions
Justification for type of information:
See endpoint summary for justification of read-across.
Qualifier:
according to
Guideline:
other: Proposed ISO Guideline and PARCOM protocol
Deviations:
no
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: direct dispersion into a stock solution

- Controls: only dilution water
Test organisms (species):
other: Acartia tonsa
Details on test organisms:
TEST ORGANISM

- Source: laboratory cultures.

- Age at study initiation (mean and range, SD): 6-8 days old

- Method of breeding: cultured unter the standard conditions according to the relevant Standard Operating Procedure

- Feeding during test: no


ACCLIMATION

- Acclimation period: not reported
Test type:
static
Water media type:
saltwater
Limit test:
no
Total exposure duration:
48 h
Test temperature:
The test was carried out at 20 degrees C
pH:
The pH of the control and all test concentrations ranged between 7.2 and 8.0.
Dissolved oxygen:
greater than or equal to 7.1 mg/l
Salinity:
ca. 28 parts per thousand
Nominal and measured concentrations:
Nominal test concentrations were 56, 100, 180, 320 and 560 mg/l.
Details on test conditions:
TEST SYSTEM

- Test vessel: scintillation vial.

- Type (delete if not applicable): covered with a perspex plate

- Material, size, headspace, fill volume: 10 ml of test medium in a vial

- No. of organisms per vessel: Each vial contained one copepodite

- No. of vessels per concentration (replicates): 10 vials per treatment. 

- No. of vessels per control (replicates): 10 vials per treatment. 


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Natural seawater passed through sand filter, a carbon filter and then a 5um membrane filter before use. Diluted with distilled water.

- Culture medium different from test medium: no

- Intervals of water quality measurement: The pH and oxygen concentrations were measured in control and test solutions at the beginning and the end of the test.


OTHER TEST CONDITIONS

- Adjustment of pH: not reported

- Photoperiod: 16 hour light-8 hour dark cycle. And two transition periods of 0.5 of twilight.

- Light intensity: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility, every 24 h


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 1.8

- Range finding study: yes, details not reported
Reference substance (positive control):
no
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
140 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 250 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Reported statistics and error estimates:
NOEC determined as highest test concentration in which at least 90% of test organisms survived. LC50 calculation not required as 50% mortality was not achieved.

Result expressed as nominal concentration. Properties of the test substance and evidence from other studies (where
concentrations were measured) indicate that nominal and measured concentrations are likely to be in good agreement.


Table 1. Mortality of Acartia tonsa during the 48 h exposure to DTPMP xNa.

 Time (h)  Nominal concentrations (mg/l)
 56  100  180  320  560
 0  0  0  0  0  0
 48  1/10 1/10   1/10  0/10  1/10  1/10


24 hr LC50: >1000 mg/l.
NOEC based on swimming behaviour/mobility.

Validity criteria fulfilled:
yes
Conclusions:
A reliable 48 h EC50 value of >250 mg active acid/l has been determined for the effects of DTPMP-xNa on the immobility of the marine copepod Acartia tonsa.
Endpoint:
short-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:
test procedure in accordance with national standard methods with acceptable restrictions
Justification for type of information:
See endpoint summary for justification of read-across.
Qualifier:
according to
Guideline:
other: Methods for Acute Toxicity Tests with Fish, Macroinvertebrates, and Amphibians, USEPA, 1975.
Deviations:
not specified
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: a 500 ml stock solution was prepared by manual dispersion for each concentration. The solution was divided in triplicates beakers to provide replicate exposure treatments. Animals were assigned to each test beaker within 30 minutes after the compound was added.

- Controls: dilution water
Test organisms (species):
other: Chironomus tentans (aquatic insect)
Details on test organisms:
TEST ORGANISM

- Common name: midge

- Source: Midge larvae were obtained from in-house laboratory cultures at Bionomic Laboratory.

- Method of breeding: not reported

- Feeding during test: no



ACCLIMATION

- Acclimation period: not reported

- Acclimation conditions (same as test or not): same dilution water used in test

- Type and amount of food: not reported

- Health during acclimation (any mortality observed): not reported
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Test temperature:
21 degrees C +/- 1
Nominal and measured concentrations:
Nominal test concentrations were 25298, 18070, 13550, 10119, and 7589 mg/l as active acid.
Details on test conditions:
TEST SYSTEM

- Test vessel: beakers. The substrate consisted of white paper towel, homogenised in water with a Waring blender. The larvae used this for construction of dwelling tubes.

- Material, size, headspace, fill volume: 250 ml vessels containing 166 ml of test solution.

- Aeration: no

- Renewal rate of test solution (frequency/flow rate): not reported

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 3

- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: well water, filtered through polyester fiber and sterilised with an ultraviolet steriliser to remove any micro-organisms prior to use in tests.

- Culture medium different from test medium: no

- Intervals of water quality measurement: not reported

OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: not reported
- Light intensity: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality, every 24 h


TEST CONCENTRATIONS

- Spacing factor for test concentrations: approx. 1.35

- Range finding study: not reported
Reference substance (positive control):
no
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
7 589 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
9 910 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: (7200 - 13500)
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
15 100 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Details on results:
- Mortality of control: 0%

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: an maber colour which appeared to be proportional to the concentration was observed.

- Effect concentrations exceeding solubility of substance in test medium: no, the water solubility of the substance is 500 g/L
Reported statistics and error estimates:
 LC50 values and 95% confidence intervals determined by least squares regression analysis of concentrations expressed as logarithms and percentage mortalities expressed as probits

Result expressed as nominal concentration. Properties of the test substance and evidence from other studies (where
concentrations were measured) indicate that nominal and measured concentrations are likely to be in good agreement.

Validity criteria fulfilled:
yes
Remarks:
for control mortality, water quality parameters not reported
Conclusions:
A reliable 48 h EC50 value of 9910 mg active acid/l has been determined for the effects of DTPMP acid on the mortality of the freshwater insect Chironomus tentans. The organisms is normally used for sediment tests, however since this is an aqeuous exposure, the study has been considered in the freshwater aquatic assessment. No water quality data has been presented. Since there were no mortality in the controls and the pattern of mortality appeared regular it can be safely assumed that water quality parameters were within the norm.
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
See attached documents for justification of read-across.
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
9 910 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 250 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility

Description of key information

(48 h) EC50 9910 mg active acid/L (r-a) C. tentans

(96 h) LC50 >252 mg active acid/L A. tonsa

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
9 910 mg/L

Additional information

Freshwater

A study is available indicating the short term toxicity of DTPMP2Na salts to Daphnia magna to be in the range 192-250 mg/l (Zeneca 1995). An insufficient level of detail is reported in the test to determine whether pH had an affect on the mortality of the test organism and the study has been assigned reliablity 4 by the reviewer.

However, a reliable 48 h EC50 value of 9910 mg active acid/l has been determined for the effects of DTPMP acid on the mortality of the freshwater insect Chironomus tentans. The organism is normally used for sediment tests, however since this is an aqueous exposure, the study has been considered in the freshwater aquatic assessment. No water quality data have been presented. Since there were no mortality in the controls and the pattern of mortality appeared regular it can be safely assumed that water quality parameters were within the norm.

The results of tests conducted on DTPMP and its salts are directly comparable, because the substance will fully dissociate in solution and the ionisation state will depend only on the pH of the test medium. The counterion is not considered to contribute to effects in invertebrates. At environmentally-relevant pH values, DTPMP will be ionised typically 6-8 times, and will form stable complexes with metal ions.

Here, the value of 9910 mg equivalent active acid/L may be directly read-across. It is convenient to convert the result into units of mg DTPMP Na salt/L at relevant conditions of pH by considering the ionisation state of DTPMP (CAS 15827-60-8) at the 9910 mg/L concentration.

The pH range of the test medium has not been reported but is assumed to be around 7. At this pH DTPMP is ionised 7 times (pKa7= pH 7.23), hence the calculation is to determine the concentration of DTPMP Na (where Na = 7Na) which would be equivalent to 9910 mg active acid/L. In the calculation we also remove the number of hydrogen atoms substituted by the sodium salt from the MW of DTPMP, in this case 7.

The 48 h EC50 for DTPMP acid is 9910 mg/L, which is equivalent to a 48 h EC50 value of 9910 * 1.26 = 12487 mg/L DTPMP Na

[using MW(DTPMP-7Na)/MW(DTPMP) = 573.2+((21.982-1.008)*7) / 573.2= 1.26

 

Marine

 

A reliable 48 h EC50 value of >250 mg active acid/l has been determined for the effects of DTPMP7Na on the immobility of the marine copepod Acartia tonsa.

The pH range of the test medium has been reported to be between 7 and 8. At this pH DTPMP is ionised ca. 7 times (pKa7= pH 7.23), hence the calculation is to determine the concentration of DTPMP Na (where Na = 7Na) which would be equivalent to >250 mg active acid/L. In the calculation we also remove the number of hydrogen atoms substituted by the sodium salt from the MW of DTPMP, in this case 7.

The 48 h EC50 for DTPMP acid is >250 mg/L, which is equivalent to a 48 h EC50 value of >250 * 1.26 = >315 mg/L DTPMP Na

[using MW(DTPMP-7Na)/MW(DTPMP) = 573.2+((21.982-1.008)*7) / 573.2= 1.26