Registration Dossier

Classification & Labelling & PBT assessment

PBT assessment

Administrative data

PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Classification of 1-(6-methoxy-2-naphthyl)ethan-1-one for effects in the environment

Available data for the chemical 1-(6-methoxy-2-naphthyl)ethan-1-one, indicates toxic effect in all the three trophic levels namely fish, invertebrates and algae if one considers only the LC50 and EC50 values. However, it is important to note that the chemical is readily bio-degradable, has a BCF value of maximum 10 and the Log Kow value is also less than 4. Therefore, since all the conditions are not met as mentioned in the CLP regulation for classifiation in the aquatic environment, the chemical is not considered to be toxic to the aquatic environment.

Among the lower values used for the calculation of PNEC is a 96 hours LC50 value of 5.21 in fish.

 

In determining the classification appropriate to 1-(6-methoxy-2-naphthyl)ethan-1-one, 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

Available information suggests that 1-(6-methoxy-2-naphthyl)ethan-1-one is non persistent in the water and soil environment. Though it is persistent in the sediment medium since there is no diffusion in this medium the long half life is not critical.  Thus it can be inferred that 1-(6-methoxy-2-naphthyl)ethan-1-one is non persistent in character. 

 

1-(6-methoxy-2-naphthyl)ethan-1-one is non persistent as it does not satisfy the criteria for classification as persistent (P). 

 

Potential to accumulate

Predicted and measured log Kow values for 1-(6-methoxy-2-naphthyl)ethan-1-one is less than 4 (Log Kow = 1.52). The potential for 1-(6-methoxy-2-naphthyl)ethan-1-one to bioaccumulate in the tissues of organisms that inhabit aquatic or terrestrial matrices is negligible as the BCF factor for the substance is 10 which is much below the threshold value of 2000.  

 

Thus, 1-(6-methoxy-2-naphthyl)ethan-1-one does not satisfy the criterion for classification as bioaccumulative (B).

 

The toxicity values of fish, invertebrates and algae are LC50 = 5.21 mg/L, EC50 = 15.76 mg/L are EC50 = 12.25 mg/L, respectively. 

Available data for the chemical 1-(6-methoxy-2-naphthyl)ethan-1-one, indicates toxic effect in all the three trophic levels namely fish, invertebrates and algae if one considers only the LC50 and EC50 values. However, it is important to note that the chemical is readily bio-degradable, has a BCF value of maximum 10 and the Log Kow value is also less than 4. Therefore, since all the conditions are not met as mentioned in the CLP regulation for classifiation in the aquatic environment, the chemical is not considered to be toxic to the aquatic environment.

So, 1-(6-methoxy-2-naphthyl)ethan-1-one does not satisfy the environmental effects criterion for classification as toxic (T).

 

Thus, based on all of the above, it can be inferred that 1-(6-methoxy-2-naphthyl)ethan-1-one is not a PBT chemical.