Reaction mass of tetramethylammonium hypochlorite and tetramethylammonium chloride

Short-term toxicity to aquatic invertebrates

Description of key information

Key study on the 48-h toxicity to invertebrates (Daphnia magna) was determined according to the OECD 201 and in accordance with GLP. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.94 mg/L

Additional information

Key study on the 48-h toxicity to invertebrates (Daphnia magna) was determined according to the OECD 202 and in accordance with GLP. Since the target substance is analogue to the inorganic household bleaching agents (e.g. sodium hypochlorite) the literature data from sodium hypochlorite was used as a supporting read-across data to evaluate the aquatic toxicity to invertebrates.

The key study was conducted for the target substance by using the nominal concentrations. Because the substance is a multi-constituent and the intrinsic properties are related to the available chlorine content, the most feasible method to measure the test concentrations is to use titration. However, since the test concentrations were very low the detection limit of the analysing method caused limitations and the nominal concentrations were used instead of measured ones. In addition, the pH adjustment was not feasible because the target substance will decompose if the pH is adjusted. Based on the key study results, the key value for the 24-h EC50 is 0.98 mg/L and the 48 -h EC50 0.94 mg/L, respectively.

 

Based on the supporting studies on analogue household bleaching agents (sodium hypochlorite) the intrinsic properties are similarly related to the available chlorine and the aquatic toxicity determined for these analogue substances indicate toxicity to invertebrates. Valid data have been found only for crustaceans and the following conclusions on hypochlorite toxicity to invertebrates have been presented in the EU risk Assessment report for sodium hypochlorite in 2007:

 

Taylor (1993) tested the acute toxicity of various forms of free and combined chlorine to Ceriodaphnia dubia in standard 24h toxicity tests, carried out under static and flow through conditions. Sodium hypochlorite was tested at pH 7 for HOCl (70% HOCl and 30% OCl-) and pH 8 for OCl- (80% OCl and 20% HOCl). In static tests the decay of free chlorine was very rapid (1 minute and 7 hours in tests with or without food, respectively) and the results were not considered valid. Flow-through tests (without food) were carried out to maintain a constant concentration over the exposure time. The toxicity of free chlorine in these tests was much higher: 5 and 6 μg/l for HOCl and OCl -, respectively. The test concentrations were calculated from measured chlorine concentration of the stock solution and dilution ratios, the number of concentrations and the 24h LC50s determined by graphical interpolation. Based on the EU risk assessment report (2007), the 24h LC50 of 5 μg FAC*/l was selected as valid value for short-term toxicity.  

 

In addition to the EU risk assessment report, the supporting information on hypochlorite toxicity to fresh water glochidia and marine brine shrimp and Daphnia mendotae was found. The supporting study by Valenti et al. (2006) was conducted for calcium hypochlorite. In this study, various glochidia were exposed to calcium hypochlorite in a static toxicity test. Test concentrations were measured as total residual chlorine (TRC**) concentrations by using amperometric titration. Mortality of the glochidia was observed at the end of 24, 48 and 72 hour test periods and LC50 values were determined. The 24 h LC50 values ranged between 70 to 220 µg total residual chlorine (TRC)/L, 48 h LC50 values between 80 to 260 µg TRC/L, and 72 h LC50 values from 90 to 180 µg TRC/L.  

 

Raikow et al. (2007) investigated the toxicity of sodium hypochlorite and glutaraldehyde to invertebrates by exposing them to resting eggs of Daphnia mendotae and Artemia sp. Eggs were exposed for 24 h to control and test chemical at nominal concentrations up to 300 mg/L. As a result the 24h LC50 of 34.6 mg/L for Artemia sp. and 55.0 mg/L for Daphnia mendotae were determined.  

 

*FAC = free available chlorine

**TRC = total residual chlorine