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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB

Classification of 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid for effects in the environment

In determining the classification appropriate to 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid, it is necessary to consider all available evidence concerning its persistence, potential to accumulate and predicted or observed environmental fate and behaviour that may present a long-term and/or delayed danger to the structure and/or functioning of aquatic ecosystems. These points are considered below. 



Available data indicates that 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is not persistent in the aquatic and soil environment. Moreover, its persistent characteristics is only observed in the sediment compartment and hence it has been concluded that 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is not persistent in nature.  


Thus, 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is classified as a not persistent chemical. 


Potential to accumulate

The estimated log Kow values for 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is less than 4 (Log Kow = -2.62). The potential for 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid to bioaccumulate in the tissues of organisms that inhabit aquatic or terrestrial matrices is negligible as the BCF factor for the substance is less than 2000.  


The estimated BCF of 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is highest 3.162 L/kg wet wt. and below the threshold of 2000. 


Thus, 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid does not satisfy the criterion for classification as bioaccumulative (B).


The toxicity values of fish, invertebrates and algae are LC50 = 294 and 2050000 mg/L, EC50 = 134 and 778000 mg/L and EC 50 = 39583.34 and 111000 mg/L, respectively. Also, the NOEC values of read across substance for algae is > 0.01 mg/L (1000 mg/L ) and thus these values suggest classification for aquatic toxicity will not be applicable for all of the tropic levels and the same is based on the above mentioned estimation studies.

In addition to aquatic toxicity, the substance, 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid, is not classified as carcinogenic (category 1A or 1B), germ cell mutagenic (category 1A or 1B), or toxic for reproduction (category 1A, 1B or 2) according to CLP (Regulation (EC) No 1272/2008) and there is no evidence of chronic toxicity, as identified by the classifications STOT (repeated exposure) according to Regulation (EC) No 1272/2008.

Thus, 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid does not meet the Annex XIII criterion for classification as toxic (T).


Thus, in accordance with the requirements of Annex XIII; it can be inferred that 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid is a not a PBT (including vPvB) substance.