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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Classification & Labelling & PBT assessment

PBT assessment

Administrative data

PBT assessment: overall result

PBT status:
the substance is PBT / vPvB
Justification:

Classification ofbenzidine-2, 2'-disulphonic acidfor effects in the environment

 

In determining the classification appropriate to benzidine-2,2'-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.

 

Persistence

Reliable studies are available to demonstrate that benzidine-2,2'-disulphonic acid is non persistent in the aquatic environment. However, it is persistent in the sediment and soil compartment and hence it has been concluded that benzidine-2,2'-disulphonic acid is persistent in nature.  

 

Thus, benzidine-2,2'-disulphonic acidis classified as a persistent (P) chemical. 

 

Potential to accumulate

The estimated log Kow values for benzidine-2,2'-disulphonic acid is less than 4 (Log Kow = 1.102). The potential for benzidine-2,2'-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 1000.  

 

 The estimated BCF of benzidine-2,2'-disulphonic acid is highest 3.2 dimensionless and below the threshold of 2000. 

 

Thus, benzidine-2,2'-disulphonic aciddoes not satisfy the criterion for classification as bioaccumulative (B).

 

The toxicity values of fish, invertebrates and algae are LC50 =352.955mg/L, EC50 =186.094mg/L are EC50 =403.167mg/L, respectively. These values do not suggest classification for aquatic toxicity. So,benzidine-2,2'-disulphonic acid does notsatisfy the environmental effects criterion for classification as toxic (T).

 

Thus it can be inferred thatbenzidine-2,2'-disulphonic acid is P but not bio-accumulative (B) and Toxic (T) substance.