Tetrasodium 4-amino-5-hydroxy-3,6-bis[[4-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2,7-disulphonate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Data waiving:

exposure considerations

Justification for data waiving:

other:

Justification for type of information:

1. HYPOTHESIS FOR THE DATA WAIVING
The evaluation proposed in this assessment considers the behaviour of the target in relation to its
potential acute inhalation toxicity, with particular reference to the endpoint under study (7.2.1). The
presence of unfavourable physico-chemical properties and the use of mitigation measures during
occupational exposure make the toxicity unlikely to occur for this absorption route. Following these
considerations, a data waiving is proposed.
2. SOURCE AND TARGET CHEMICAL(S)
Name: Reactive Black 5
EC number: 241-164-5
CAS number: 17095-24-8
Molecular Formula: C26-H25-N5-O19-S6.4Na
Chemical Name: Tetrasodium 4-amino-5-hydroxy-3,6-bis[[4-[[2-(sulphonatooxy)ethyl]sulphonyl]
phenyl]azo]naphthalene-2,7-disulphonate
SMILES (Canonical):
C1=CC(=CC=C1N=NC2=C(C3=C(C(=C(C=C3C=C2S(=O)(=O)[O-])S(=O)(=O)[O-])N=NC4=CC=C(
C=C4)S(=O)(=O)CCOS(=O)(=O)[O-])N)O)S(=O)(=O)CCOS(=O)(=O)[O-].[Na+].[Na+].[Na+].[Na+]
The section “1.2 Composition” of the registration dossier reports the available information about the
composition of the target dyes.
3. JUSTIFICATION FOR DATA WAIVING
According to the REACH Annex VIII (8.5.2) the evaluation of acute inhalation toxicity should not be
conducted if the inhalation exposure to human is considered unlikely based on the vapour pressure
of the test substance and the impossibility to generate aereosol, particles of droplets of an inhalable
size.
Reactive Black 5 is a high melting point (MP) and boiling point (BP) solid (MP > 360°C) [1].
According to Table R.7.12 - 2 of the Guidance on Information Requirements and Chemical
Safety Assessment Chapter R.7c, substances with BP >150 °C are characterised by low volatility
and may be not available for inhalation as vapours. Similarly, based on Annex VII of REACH 7.5,
vapour pressure evaluation should not be conducted if the MP of the test substance is >300 °C, due
to absence of volatility and risks of absorption through inhalation.
Moreover, the very low octanol/water partition coefficient (logP = -4.13) [2] (pag. 13) denotes a very
low lipophilicity that makes the target unable to cross biological membranes and cause toxicity if
inhaled.
Exposure of Reactive Black 5 is limited to trained operating personnel in limited locations and the
substance is only supplied to the market as a dust-free powder formulation. Therefore, the
inhalation toxicity study in animals was considered unwarranted. In relation to the possible
occupational exposure, the contact with the potential dust is limited by the treatment in fabrication
with anti-dusting compound (vaseline oil) and the use of personal protection equipments (PPE) by
operators.

Applicant's summary and conclusion

Conclusions:

Based on the information provided it is possible to infer that the target Reactive Black 5 is unlikely
to be toxic with reference to the endpoint studied (7.2.2) due to unfavourable physico-chemical
properties and the use of mitigation measures during occupational exposure.

Executive summary:

The information presented here suggested that Reactive Black 5 is non-toxic through inhalation