Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

SPECIATION OF THE REGISTRATION SUBSTANCE

The registration substance is a monobasic acid with a pKa of 4.7 (see IUCLID Chapter 4.21). This means that in aqueous medium at pH 7 >99% exists as salt.

REGISTRATION SUBSTANCE AND READ-ACROSS

The registration substance Tetrapropenyl succinimido caproic acid (Tetra-PSCA), CAS No. 1424148-99-1 is a structural homologue of Pentapropenyl succinimido caproic acid (Penta-PSCA), CAS No. 1424148-94-6. Both substance are not only structurally very similar they also have a similar Octanol-water partitioning coefficient: Tetra-PSCA Log Kow=3.7 and Penta-PSCA Log Kow=3.6. Assuming a narcotic mode of action the ecotoxicity of both substances should be comparable based on their comparable Log Kow. Both substances have also comparable vapour pressures and Critical Micelle Concentrations. Therefore it is justified to use substance data from Penta-PSCA for read-across to Tetra-PSCA.

In the table below the available acute and chronic ecotoxicity data for all three trophic levels are given for the read-across substance Penta-PSCA:

Test Guideline Endpoint Value
      (mg/L)
Acute Fish 203 LC50 (96h) 100
Acute Daphnia 202 EC50 (48h) 2.6
Algae 201 ErC50 (72h) 38
Microorganisms 209 NOEC (3h) 1000
       
Chronic Daphnia 202 EC10 repro(21d) 1.7
Algae 201 ErC10 (72h) 9.6

All acute and chronic freshwater test results are > 1 mg/L.