reaction product of: C.I. Leuco Sulfur Black 1 with (3-chloro-2-hydroxypropyl)trimethylammonium chloride

Endpoint summary

Description of key information

NOEL = NOAEL (oral, rat, 28 days) = 50 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Repeated Dose Toxicity: Oral

The repeated dose toxicity of the substance was evaluated in a subacute 28-day oral toxicity study according to the OECD Guideline 407 (1981) and method B.7 of the Directive 92/69 EEC. The substance was administered daily by oral gavage to SPF-bred Wistar rats of both sexes for a period of 28 days, followed by a 14-day recovery period. Test animals were randomly assigned into four groups at dose levels of 0, 50, 200 and 1000 mg/kg bw/day (5 males and 5 females per dose level) whereby the control group received only the vehicle (bi-distilled water) and test animals were sacrificed after a 28-day treatment period. Two additional, parallel groups received either 0 or 1000 mg/kg bw/day (5 males and 5 females per dose level) and were monitored for a 14-day recovery period following the 28-day treatment period. These animals were sacrificed after the recovery period.

Observations for clinical signs and mortality were recorded daily; body weight and food consumption measurements were taken weekly. Ophthalmoscopic examinations, blood samples and urine samples were taken at 4 weeks (both treatment and recovery groups) and 6 weeks (recovery groups only). Necropsies were performed on all test animals. Post-mortem organ weights and macroscopic and microscopic histological parameters were recorded.
All test animals administered 200 and 1000 mg/kg bw/day demonstrated clinical signs associated with pain (hunched posture) intermittently between days 1 and 11. No other clinical signs, mortality, body weight changes or food consumption abnormalities of toxicological significance were recorded. There were no treatment-related effects of toxicological significance recorded in haematology, clinical biochemistry, urinalysis or ophthalmic parameters. Reversible urine discolouration was observed in 12 out of 20 test animals administered the highest dose. No histological effects or organ weight differences of toxicological significance were observed. Bluish dicolouration was observed in various sections of the gastrointestinal tract in several test animals of the treatment-only group administered 1000 mg/kg bw/day, and only one test animal of the treatment plus recovery group (1000 mg/kg bw/day). No test animals of 0, 50 or 200 mg/kg bw/day demonstrated discolouration of the gastrointestinal tract.
Based on the hunched posture observed at 200 and 1000 mg/kg bw/day, the NOEL and NOAEL for the substance in male and female rats is 50 mg/kg bw/day. Hunched posture associated with pain was observable up to day 11 of treatment, after which it was no longer observed despite ongoing treatment. This may be due to discomfort of the substance passing through the gastrointestinal tract. Organ dysfunction was not evident and this finding was supported by an absence of microscopic findings. Gastrointestinal discolouration was evident only at a dose level of 1000 mg/kg bw/day, and was not present among test animals which underwent the 14-day recovery period except for one male. Test animals administered lower dose levels of 50 and 200 mg/kg bw/day did not demonstrate gastrointestinal discolouration.

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), substances are classified as specific target organ toxicants following repeated exposure, and are placed in one of two categories, depending upon the nature and severity of the effect(s) observed. 

Substances that have produced significant toxicity in humans or that, on the basis of evidence from studies in experimental animals, can be presumed to have the potential to produce significant toxicity in humans following repeated exposure, are classified in Category 1 for target organ toxicity (repeat exposure). Classification in Category 1 is applicable when significant toxic effects are observed in a 90-day repeated-dose animal study at low concentrations (< 10 mg/kg bw/day in oral studies, and < 20 mg/kg bw/day in dermal studies) (CLP Regulation (EC 1272/2008): Annex 1, Part 3, Table 3.9.2).

Substances which can be presumed to have the potential to be harmful to human health following repeated exposure, based on evidence from animal studies, are classified in Category 2. Classification in Category 2 is applicable when significant toxic effects are observed in a 90-day repeated-dose animal study at generally moderate exposure concentrations (10 to 100 mg/kg bw/day in oral studies, and 20 to 200 mg/kg bw/day in dermal studies) (CLP Regulation (EC 1272/2008): Annex 1, Part 3, Table 3.9.3).

Equivalent guidance values for an equivalent 28-day study period raises the concentration values for classification by three-fold: classification in category 1 is applicable at low concentrations (< 30 mg/kg bw/day in oral studies; < 60 mg/kg bw/day in dermal studies) and in Category 2 at generally moderate concentrations (30 to 300 mg/kg bw/day in oral studies, 60 to 600 mg/kg bw/day in dermal studies).

Based on the available repeated dose subacute 28-day Oral Toxicity Study, no classification of the substance is warranted for specific target organ toxicity – repeated exposure (CLP Regulation EC 1272/2008).