Disodium 4,4'-bis[[4-anilino-6-[(2-hydroxyethyl)amino]-1,3,5-triazin-2-yl]amino]stilbene-2,2'-disulphonate

Short-term toxicity to fish

Description of key information

LC50 96h zebrafish > 1000 mg/l

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 000 mg/L

Additional information

The short term toxicity to fish was tested on the similar substance 16324-27-9, but only the test summaries are available. All studies are consistent and indicate a LC50 on Zebrafish at 96 h higher than 1000 mg/l. The substance is the analogous monohydroxiethylamino derivative tetrasulphonated, sodium salt. It has therefore the same functional groups, but it is more soluble (140 g/l for CAS 16324-27-9 vs 30.2 g/l for CAS 17985-73-5). Sulphonated groups are known for not having a toxic effect, on the contrary, to facilitate the metabolism and the excretion of more water soluble metabolites. Therefore the similar substance is a conservative representative for water toxicity, because it is more bioavailable.

Further studies are reported on the similar substances dihydroxyethylamino derivative, CAS 4193-55-9, CAS 70942-01-7 and CAS 16470-24-9, the disulphonated sodium salt, disulphonated sodium/potassium salt and the tetrasulphonated sodium salt, respectively. The substance under registration is a potential direct metabolite, and phys-chemical properties are very similar.

Two fish acute toxicity tests are available (Ciba-Geigy, 1994 and 1998) on CAS 16090-02-1 pre-treated with light in order to obtain a high percentage of photodegraded products and verify their impact on aquatic toxicity. Both tests resulted in a LC50 > 100 mg/l, demonstrating that those degradation products are no more dangerous for the environment than the parent compounds.

In conclusion, no fish acute toxicity is expected for CAS 17985-73-5.