Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Cyanuric chloride hydrolyses fast in water. Therefore tests on cyanuric chloride are technically not feasible.

An intermediate hydrolysis product and a final hydrolysis product of cyanuric chloride is 2,4(1H,3H)-dione,6-chloro-, sodium salt (CAS no.: 32998-00-8) and isocyanuric acid (CAS no.: 108-80-5). Therefore these degradation products were used for a read across approach.

Short-term toxicity to fish:

In the study 90-0015-DGO the analogous substance 2-chlor-4, 6-dihydroxy-1,3,5-triazin sodium salt (CAS no. 32998-00-8) was tested for toxicity to fish in a 96 h-static test according to EU-method C.1 and OECD guideline 203. The LC50 was assessed to be > 1000 mg/L.

Long-term toxicity to fish:

In the study 97-0708-FGO_en isocyanuric acid (CAS no.: 108-80-5) was tested for toxicity to fish in a prolonged 14 day test according to OECD guideline 204.

The 14-day maximum no-observable effect concentration (NOEC), 7-day median lethal concentration (LC50) and the 14-day median lethal concentration (LC50) were determined to be > 100.0 mg/L (nominal concentration).

Short-term toxicity to aquatic invertebrates:

The read across substance isocyanuric acid (CAS no.: 108 -80 -5) (final hydrolysis product of the hydrolysis of cyanuric chloride) was tested for toxicity to aquatic freshwater in a 48 h-static test according to OECD gudieline 202 (97 -0702 -FGO_en). The EC50 (48h) was assessed to be 1000 mg/L.

Long-term toxicity to aquatic invertebrates:

A long-term aquatic toxicity test (study 97-0704-FGO_en) on aquatic invertebrates was performed using isocyanuric acid (CAS no.: 108-80-5).

- The 14 day 50% lethal concentration (LC50) for Daphnia Magna was determined to be 12.39 mg/L (95% confidence interval: 7.99 mg/L to 19.61 mg/L) (Probit method)

The 21 day 50% lethal concentration (LC50) for Daphnia Magna was determined to be 9.55 mg/L (95% confidence interval: 6.22 mg/L to 14.52 mg/L) (Probit method)

- The 14 day 50% reproduction inhibition concentration (ErC50) for Daphnia Magna was determined to be 9.36 mg/L (95% confidence interval: 1.32 mg/L to 42.77 mg/L) (Probit method)

- The 21 day 50% reproduction inhibition concentration (ErC50) for Daphnia Magna was determined to be 65.86 mg/L (95% confidence interval: 54.47 mg/L to 82.70 mg/L) (Moving average method)

- Maximum non-observable effect concentration (NOECr) was determined to be 32.00 mg/L.

- Lowest concentration (LOECr) at which a significant difference with the control group can be observed was determined to be 100.00 mg/L (The above concentrations are values based upon all the established values).

Toxicity to aquatic algae:

Cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) has a low solubility and is hydrolytically unstable therefore a test on toxicity to aquatic algae and cyanobacteria is technically not feasible.

Therefore the results for the degradation product of cyanuric chloride (isocyanuric acid, CAs no.: 108 -80-5) are suitable as well. In a study (97-0700-FGO_en) isocyanuric acid was tested for toxicity to algae in a 72 h-static test according to OECD guideline 201. The EC50 based on the area under the growth curve and based on the growth rate was determined to be 620.0 mg/L and 780.0 mg/L, 800.0 mg/L, respectively. The No-observable effect concentration (NOEC) was determined to be 62.5 mg/L (area method) and 250 mg/mL and 125.0 mg/L (growth velocity method), respectively.

Toxicity to microorganisms: In the study (79-0013-DKO) no effect of cyanuric chloride or its hydrolysis degradation products on bacteria in sludge (dehydrogenase activity) was reported. As concentrations of cyanuric chloride up to to 576 mg/L dissolved in water did not show any negative effects on the activated sludge, the NOEC of cyanuric chloride is 576 mg/L.