Di(µ-2,2´,2´´-nitrilotris(ethanol)-diperchlorato)dinatrium

Short-term toxicity to fish

Description of key information

EC50 (bluegill sunfish, 96 h) = 1470 mg/l (mean measured)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 470 mg/L

Additional information

No data are available for the assessment of the acute toxicity potential of the substance to fish. For this reason data on the dissociation substances are used for the the evaluation of short-term toxicity to fish. Justification for read across is given in section 13 of IUCLID.

Three studies from literature are used for the assessment of the toxicity of perchlorate to the fish after 96 hours of exposure. In all three tests a control run in parallel and test concentration analysis were measured at the test initiation and end. Water parameters such as temperature, dissolved oxygen, and pH were also measured in test chambers on a daily basis.

In one study, ten zebrafish Danio rerio lavrae were exposed to the substance in five concentrations in a static-renewal test according to ASTM E729 -90. LC50 and their 95 % confidence limits were detrmined using the probit procedure. LC50 (96 h) = 1365 mg/l (measured).

In the second study, ten juvenille zebrafish Danio rerio (per replicate) were exposed to five concentrations of the substance in the static-renewal test according to the ASTM Standard E792 -96. The toxicity was determined by converting mortality data to toxic units and LC50 were determined by the Probit Unit procedure; LC50 (96 h) = 2532 mg/l (measured).

In another study the toxicity to rainbow trout fry and juvenille bluegill sunfish was assessed in a flow-through test according to EPA OPPTS 850.1075 and ASTM E729-96. The fish were exposed to five different concentrations of the substance and to a perchlorate- free control for 96 hours. Biological observations and test monitoring were performed on a daily basis at minimum. EC50 was used instead of LC50 and it was based not only on mortality but in addition on severe effects, such as loss of equilibrium and immobilization. No mortality was observed in the control or the sodium control in both tests. No sublethal effects were observed during the test; all observations were either of mortality or normal behavior. Rainbow trout: EC50 (96 h) = 2010 mg/l(mean measured); NOEC (96 h) = 1460 mg/l; LOEC (96 h) = 2760 mg/l. For bluegill sunfish: EC50 (96 h) = 1470 mg/l (mean measured); NOEC (96 h) = 547 mg/l; LOEC (96 h) = 1260 mg/l.

Two studies from literature are used for the assessment of the toxicity of triethanolamine to fish.

In one study, the toxicity of test material to fish was assessed in the flow-through test. For this reason, 20 Fathead minnows were exposed to the substance at five concentrations for 96 hours. Fish were observed for mortality, behaviour and toxicity signs at 2-8, 24, 48, 72 and 96 hr after start initiation. Water temperature, dissolved oxygen and pH were made in each exposure chamber daily where fish survived. The LC50 (concentration causing 50 % mortality of the fish) and EC50 (concentration causing 50 % of the fish to show an adverse effect) were estimated. Affected fish lost schooling behaviour, were hypoactive and darkly colored, had increased respiration and lost equilibrium prior to death. LC50 (96 h) = 11.8 g/l (measured), EC50 (96 h) = 11.8 g/l (measured).

In another study, the toxicity to fish was evaluated according to APHA (1971) Standard methods for the examination of water and wastewater. Method no. 231. Ten Goldfish were exposed to the test substance (test concentrations not specified) for 24 hours. The test was discontinued after 24 h since the TL_mvalue was higher than 5000 mg/l. TL_m, the concentration at which 50 % of the fish survived the test was obtained by interpolation from a graph of the logarithm of the concentration versus mortality. LC50 (24 h) > 5000 mg/l (measured).

All the studies used an adequate number of fish in a different life cycle in order to assess the toxicity potential; in the case of perchlorate juvenille zebrafish Danio rerio, rainbow trout fry and juvenille bluegill sunfish were used. The species used are according to the species recommended by the OECD Guideline 203 while the CLP recommends the use of juvenille for classification purposes (if not smaller size fish). In the case of triethanolamine, goldfish and Fathead minnows were used. The exposure duration was the same in all the studies besides one study on triethanolamine where a shorter exposure was used (24 hrs instead of 96 hrs). The purity of the test substances was in general higher than 97 % while in two studies it was not specified. Test concentrations are indicated as measured in all studies.

For chemical safety assessment an EC50 of 1470 mg/l is used based on a study on perchlorate. The EC50 was determined based on severe effects such as loss of equilibrium and immobilization in addition to mortality observations. This value was chocen among the other obtained values since it is determined by a toxicity study with an adequate number of fish and concentrations tested, in which water parameters and test concentrations were monitored. Furthermore, this value is one of the lowest values obtained in all the studies available (worst case senario). A lowest value determined in another study was 1365 mg/l (LD50) but even if this value is lower, it is not used for the chemical safety assessment; an EC50 instead of LC50 is considered as more appropriate for the evaluation of the short-term toxicity effects on fish since it takes in consideration severe effects and not only mortality.