Registration Dossier

Administrative data

Description of key information

The acute oral toxicity of MBB or MBB SULFATE 1:1 was determined based on the maximum tolerated dose (MTD) after oral application in in vivo genotoxicity studies in rats carried out with the sulfate salt. The determination of the MTD (with respect to the number of animals used and dose selection) was in line with the OECD guideline 423 for the determination of acute oral toxicity. The approach to determine the acute oral toxicity by using MTD data from in vivo genotoxicity studies is accepted by the German and EU regulatory agencies  and is based on the current state-of-the-art science. The calculated oral LD50 values (LD50, calc, oral) for the sulfate salt and free base of 2- METHOXY-METHYL-P-PHENYLENEDIAMINE were determined to be 150 mg/kg bw and 91.5 mg/kg bw, respectively. The LD50, calc, oral for the sulfate salt (150 mg/kg bw) was used for the route extrapolation calculations, since the in vivo toxicity and kinetics assays used in the calculations were also carried out with the sulfate salt.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
Value:
91.5 mg/kg bw
Quality of whole database:
free base

Acute toxicity: via inhalation route

Endpoint conclusion
Dose descriptor:
LC50
Value:
1 080 mg/m³
Quality of whole database:
free base

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
Value:
366 mg/kg bw
Quality of whole database:
free base

Additional information

The acute inhalational and dermal toxicity of 2-METHOXY-METHYL-P- HENYLENEDIAMINE was determined using kinetics-based data derived from an ADME study in rats with the sulfate salt.

The calculated LD50 for the oral toxicity was 150 mg/kg b.w. and 91.5 mg/kg bw for the for the sulfate salt and free base, respectively.

The calculated LC50 for the inhalation toxicity (LC50 calc inhal.) was 1.77 mg/L and 1.08 mg/L for the sulfate salt and free base, respectively. When these concentrations are combined with the results of in vitro eye irritation studies, it can be concluded that 2-METHOXY-METHYL-P-PHENYLENEDIAMINE would not have a local effect in the lungs.

The calculated LD50 value for the dermal toxicity was 600 mg/kg bw and 366 mg/kg bw for the for the sulfate salt and free base, respectively.

Justification for classification or non-classification

The LD50 values determined or calculated served as criteria for applying CLP classification.

The substance2-METHOXY-METHYL-P-PHENYLENEDIAMINE was considered as acute tox 3 : toxic if swallowed, in contact with skin (H301,H311) and acute tox 4 : harmful if inhaled (H332)