Tridecanamine, N-tridecyl-, branched and linear

Endpoint summary

Description of key information

Short-term toxicity to fish:

With high probability acutely not harmful to fish (96 -h LL50 > 100 mg/L based on loading rate)

Long-term toxicity to fish:

The Substance is poorly soluble in water and long-term toxicity testing should be considered according to REACH Regulation, Section 9.1.3, Column 2. However, the Registrant will not perform a study on the long-term toxicity to fish, but adapt the information requirements as follows.  The Registrant wants to emphasize that with regard to the available acute toxicity data for DTDA, aquatic invertebrates are more sensitive to the Substance than fish. Even if the short-term toxicity data might not give a true measure of the toxicity of this poorly water-soluble substance, the data still reflect the relative sensitivity of the organisms to the Substance. The 96-h LL50 for fish was determined to be > 100 mg/L, while the effect levels for aquatic invertebrates and algae were lower (aquatic invertebrates: 48-h EL50 = 46.9 mg/L; algae: 72-h ErL50 = 12.3 mg/L). Avoiding unnecessary testing of vertebrate animals is in line with the REACH Regulation 1907/2006, which states in §25 that testing on vertebrate animal shall be undertaken as a last resort. Therefore, the testing strategy aims at investigating the long-term toxicity on aquatic invertebrates in a first step. Depending on the outcome of this test, a long-term study on fish will be performed.

Short-term toxicity to aquatic invertebrates:

Acutely harmful to aquatic invertebrates (48 -h EL50 = 46.9 mg/L based on loading rate)

Long-term toxicity to aquatic invertebrates:

Test proposal: OECD 211, Daphnia magna reproduction test

Growth inhibition to aquatic algae:

Acutely harmful to aquatic algae (72 -h ErL50 = 12.3 mg/L based on loading rate)

Toxicity to microorganisms:

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriately low concentrations (180 -min EC10 = 490 mg/L based on nominal concentrations).

Additional information

Composition of DTDA (CAS 101012 -97 -9)

Di-tridecylamine, branched and linear (CAS 101012-97-9) is a mixture of (predominantly) di-alkyl amines with varying alkyl-chain length in a range between C24 and C27. The main fraction consists of isomers of di-tridecylamines (C26H55N). Secondary fractions were detected to have chain lengths of C13 and C39. The following structures and relative fractions were proposed:

Table 1: Composition of DTDA (CAS 101012-97-9) according to analytical report 17Y36412 (BASF SE, 2017)

Isomers	Quantity
Secondary fraction: Isomers of tridecyl amines
Isomers of C13H29N	0.9 %
Main fraction: Homologues of Dialkyl amines
Isomers of C24H51N	< 0.1 %
Isomers of C25H53N	0.4 – 0.5 %
Isomers of C26H55N	92 – 94 %
Isomers of C27H57N	0.25 – 0.35 %
Secondary fraction: Homologues of trialkyl amines
Isomers of C39H79N and C39H81N	< 5.2 %

Remark:

Due to its low water solubility, in the key studies on acute toxicity to fish, daphnids and algae the test item (DTDA, CAS 101012 -97 -9) was applied as water accommodated fraction (WAF) as described in OECD TG 23. This procedure ensures that no undissolved test material is applied. In these studies, toxic effects expressed in a concentration-response relationship were observed although the (nominal) concentrations were far above the water solubility of DTDA of ca. 30 µg/L. These effects might be explained by the mono alkyl amine fraction (C13H29N) of 0.9%. These isomers of the C13H29N fraction are also known as tridecylamine, branched and linear (TDA, b+l, CAS 86089 -17 -0). This compound has a higher water solubility of 15 - 40 mg/L. The acute toxicity values (LC/EC50) for effects of TDA, b+l on fish, daphnids and algae are known to be in a range between 15 and 65 µg/L. These effect data correspond with the theoretical concentrations of TDA, b+l (relative fraction 0.9%) in the above listed studies with DTDA.