Registration Dossier
Registration Dossier
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EC number: 278-145-6 | CAS number: 75234-41-2
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 29 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- other: ECHA REACH guidance & ECETOC
- Overall assessment factor (AF):
- 60
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 1 763 mg/m³
- Explanation for the modification of the dose descriptor starting point:
- As there is no inhalation study available an extrapolation using default assessment factors was performed. There was no information indicating other methods as more suitable.
- AF for dose response relationship:
- 1
- Justification:
- default, no information indicating otherwise is available
- AF for differences in duration of exposure:
- 3
- Justification:
- default, no information indicating otherwise is available
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- default, no information indicating otherwise is available
- AF for other interspecies differences:
- 1
- Justification:
- included in the allometric factor, no iformation indicating otherwise is available
- AF for intraspecies differences:
- 5
- Justification:
- The very polar test material is expected to behave very similar in all individuals of a species
- AF for the quality of the whole database:
- 1
- Justification:
- default, no information indicating otherwise is available
- AF for remaining uncertainties:
- 1
- Justification:
- default, no information indicating otherwise is available
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 441 mg/m³
- Most sensitive endpoint:
- acute toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- other: ECHA REACH Guidance and ECETOC
- Overall assessment factor (AF):
- 20
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 8 816 mg/m³
- Explanation for the modification of the dose descriptor starting point:
- As there is no inhalation study available an extrapolation using default assessment factors was performed. There was no information indicating other methods as more suitable.
- AF for dose response relationship:
- 1
- Justification:
- default, no information indicating otherwise is available
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- default, no information indicating otherwise is available
- AF for other interspecies differences:
- 1
- Justification:
- ECETOC reported in 2010 after an extensive review that there is no justification for the suggested additional factor of 2.5 for this; therefore a factor of 1 would also be acceptable. In addition, as no adverse effects were observed allometric scaling already represents a worst case.
- AF for intraspecies differences:
- 5
- Justification:
- default, no information indicating otherwise is available
- AF for the quality of the whole database:
- 1
- Justification:
- default, no information indicating otherwise is available
- AF for remaining uncertainties:
- 1
- Justification:
- default, no information indicating otherwise is available
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
- Route of original study:
- Dermal
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- low hazard (no threshold derived)
Additional information - workers
The CSR characterizes the hazards and risks associated with the manufacturing and formulation of Acid Brown 425 (AB 425). The only use of AB 425 is as a leather colorant.
The following section summarizes DNEL values derived for workers for which the main route of exposure would be dermal. Although less likely to occur, inhalation exposure is also considered. In a conservative approach, long-term systemic DNEL were calculated. AB 425 is intensely colored and difficult to remove; therefore appropriate protection measures are in place to avoid exposure to high doses.
DNEL systemic long-term, workers, dermal
The relevant dose descriptor selected as a starting point was the NOEL of 1000 mg/kg bw/day from the subacute study in rat (Hazelton 2008), as this is the highest NOAEL.
No DNEL was derived as no hazard had been identified.
DNEL systemic long-term, workers, inhalation
The relevant dose descriptor selected to derive the inhalation DNEL was the subacute oral rat NOEL of 1000 mg/kg bw/day. This dose descriptor, which is the starting point, was corrected for route-to-route extrapolation in accordance with the procedure recommended in Chapter R8 of the REACH Technical Guidance documents (May 2008) as follows:
NOAEL oral rat (NOAELoral rat) = 1000 mg/kg bw/day
Standard respiratory volume of a rat during 8 h exposure (SRvrat) = 0.38 m3
Standard respiratory volume of a human during 8 h exposure (SRvhuman) = 6.7 m3/8hr
Standard respiratory volume of a human during light activity for a worker -8 h (WSRvhuman) = 10 m3/8hr - light activity
In extrapolation to inhalation there is the implicit assumption of available knowledge how the absorption rates are compared between the two routes. The guidance proposes to take a default assessment factor of 2.
AB 425 is non-volatile and thus is assumed not to be present in vapor form.
In case of spraying applications, only coarse droplets would be an exposure which potentially could result in very low respiratory fraction. Of the inhalable fraction almost all will deposit in the upper airways, transported to pharynx and finally ingested. Hence for chronic systemic uptake, the respiratory and oral uptake can be considered to be equal, and thus no additional assessment factor is applied.
Therefore following the equation set out in Chapter R8 of the REACH Technical Guidance documents (May 2008) were:
NOECcorrfor workers = NOAELoral rat÷ SRvratx (SRvhuman÷ WSRvhuman)
Corrected NOEC = 1000 mg/kg bw/day ÷ 0.38 m3/kg bw x (6.7 m3÷ 10 m3)
Corrected NOEC = 1763.16 mg/m3
The next steps were the consideration of relevant assessment factors (AF) for interspecies difference, intraspecies variation, exposure duration, dose-response and quality of the database, as presented in Section R.8.4.3 of REACH guidance document R.8 and ECETOC TR86 (2003). The overall AF in this case corresponds to 60. The resulting DNELlong-term, workers, dermal is equivalent to 29.4 mg/m3/day.
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - General Population
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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