Nitrilotrimethylenetris(phosphonic acid)

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:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an appropriate national standard method but full details are not available. It was not conducted under GLP and no analytical monitoring was carried out.

Qualifier:

according to guideline

Guideline:

other: US EPA Methods for acute toxicity tests with fish, macroinvertebrates, and amphibians. EPA 66013-75-009. April 1975.

Deviations:

not specified

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: The test substance was diluted to make a stock solution of 100 mg/ml. In a 6 L flask well water and food was mixed. The solution was transferred into 1L volumetric flasks, mixed well, then 200 ml were drawn into the test vessels.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: water flea

- Feeding during test: The daphnids were fed at a concentration of 10 mg/l at each test medium renewal.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Nominal and measured concentrations:

Nominal test concentrations: 3.37, 6.75, 12.5 and 25 mg active acid/L.

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Material, size, headspace, fill volume: 250 ml test beakers filled with 200 ml test solution.

- Renewal rate of test solution (frequency): 2 day renewal

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4



TEST MEDIUM / WATER PARAMETERS

- Source of dilution water: Well water


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : survival and reproduction (offspring produced) at every water renewal (ca. 2 days).



RANGE-FINDING STUDY
A Range Finding study is said to have been conducted previous to the test in order to narrow down the range of concentrations in the test, however details were not reported. A short term acute test with Daphnia was also conducted which determined a 48 h EC50 equivalent to 883 mg active acid/L.

Reference substance (positive control):

no

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 25 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: adult survival and reproduction (no. of offspring)

Details on results:

- Mortality of parent animals: see Table 1 for details.

- Time to first brood release or time to hatch: the data reported shows that offspring were produced by day 9 in all treatment groups.

Reported statistics and error estimates:

For chronic data NOECs were determined by comparing means and standard errors in control vs. treated.

Table 1: Effect of ATMP on growth and survival of D. magna after 28 days (average of 4 replicates).

Nominal concentrations (mg a.a./L)	Mortality of parents		Cumulative number of offspring
	No. Alive	% mortality
Control	4.3 ± 1.2	14	143.7
25	4.0 ± 0.8	20	128.3
12.5	4.2 ± 1.5	16	139.5
6.75	4.2 ± 1.0	16	141.6
3.37	4.7 ± 0.5	6	155.4

 

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.

Not enough information is reported on water quality, however the frequency of water renewals suggests the parameters to be in acceptable ranges.

 

Validity criteria fulfilled:

not specified

Conclusions:

A 28 day NOEC value of >= 25 mg/L (as active acid) has been determined for the effects of the test substance on adult survival and reproduction of D. magna.

Description of key information

A 28-day NOEC value of ≥25 mg active acid/L has been determined for the effects of ATMP-H on adult survival and reproduction of D. magna.

Additional information

A 28-day NOEC value of ≥ 25 mg/L (as active acid) has been determined for the effects of the test substance on adult survival and reproduction of D. magna (Monsanto, 1976). The study represents the lowest reliable value available for this endpoint. A study of unknown reliability determined a NOEC of 3 mg/L (Henkel, 1984). However the pattern of results was erratic and not enough information was provided in the report to determine the cause.

A 96-hour NOEC value of 96 mg active acid/L has also been determined for the effects of ATMP-H on the growth of the eastern oyster Crassostrea virginica (EG&G, 1977).