(+)-L-arginine hydrochloride

Endpoint summary

Additional information

The experimental aquatic toxicity of L-arginine-HCl is derived by read-across from studies with L-arginine as there is weight of evidence from the behaviour of L-arginine-HCl in aquous soluation that read-across from L-arginine to L-arginine-HCL is justified for aquatic toxicity.

The results from studies for short-term toxicity to fish and daphniae reveal that L-arginine-HCl does not show aquatic toxicity and does not require classification.

The test results for acute toxicity of L-arginine to fish were:

LC50 = 2.8 g/l; LC 100 = 5.6 g/l; NOEC (mortality) = 1.8 g/l; NOEC (condition) = 1.0 g/l.

These results are converted based upon the ratio of the molecular weight. The results applying for Arg-HCl are:

LC50 = 3.4 g/l; LC 100 = 6.8 g/l; NOEC (mortality) = 2.2 g/l; NOEC (condition) = 1.2 g/l.

The test results for acute toxicity of L-arginine to daphniae were:

EC50 = 1.8 g/l; EC 100 = 5.6 g/l. NOEC (mobility) was estimated to be 1.0 g/l and NOEC (condition) was estimated to be < 1.0 g/l.

These results are converted based upon the ratio of the molecular weight. The results applying for Arg-HCl are:

EC50 = 2.2 g/l; EC 100 = 6.8 g/l. NOEC (mobility) was estimated to be 1.2 g/l and NOEC (condition) was estimated to be < 1.2 g/l.

The CSA did not trigger testing for long-term toxicity with fish or aquatic invertebrates.

EC50 for algae was calculated to be ca. 26857 mg/L.

The toxicity of L-arginine-HCl to microorganisms was derived to be EC 10 > 10 g/kg by read-across from L-arginine.

Considering the results from higher trophic levels as well as for microorganisms and an expert statement (see endpoint summary in IUCLID section 6.1.5) toxicity testing with aquatic algae was not deemed necessary.

These results do not trigger classification.

In respect of REACH Art. 14 in conjunction with REACH Annex I a CSA is required which includes an exposure assessment if the particular substance fulfils the criteria for any of most hazard classes or categories set out in Annex I to regulation 1272/2008 or is assessed to be a PBT / vPvB (for details see REACH Annex I, Section 0.6.3.). Annex I, Section 5.0 of the REACH Regulation states that the exposure assessment “shall cover any exposures that may relate to the hazards identified in Sections 1 to 4”.

Thus REACH requires that the exposure assessment is closely linked to the hazard assessment, which may identify hazards either for the environment, or for human health, or for both. The hazard assessment (including the classification) as well as the performance of an exposure assessment are focused either on possible effects on the environment or on possible effects on human health. Thus, any substance of a nature identified as hazardous to human health (and a respective classification) triggers an assessment of the exposure of humans, but not of the environment. L-arginine-HCl does not fulfil the criteria relating to environmental hazards (wording of EU-GHS, in particular Art. 3). Thus an exposure assessment within the Chemical Safety Assessment for L-arginine-HCl is not required.

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