2,4,6-trichloro-1,3,5-triazine

Endpoint summary

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.