N,N-dimethylaniline

Endpoint summary

Additional information

Stability:

Phototransformation in air:

The atmospheric oxidation half-life of N,N-dimethylaniline was estimated using the level III multimedia model. It was estimated that the substance is not persistent in air medium as the half life period of N,N-dimethylaniline in air is only 0.1 days. This indicates that N,N-dimethylaniline is rapidly phototransformed in air.

Hydrolysis:

The Hydrolysis rate constant of N,N-dimethylaniline is estimated to be 202.5296 E-12 cm3/molecule-sec. at half life of the 0.634 hrs. The estimated half life of the substance indicates that the substance is rapidly hydrolysable.

In one of the supporting study, the hydrolysis rate constant of the first order reaction of N,N-dimethylaniline at pH 5 ws found to be 3.76 h-1 at a temperature of 22°C. Thus comparing this value with the threshold value of 30 days, it can be concluded that the chemical will not persist in the environment and shal be subject to rapid hydrolysis/oxidation.

Phototransformation in water:

No experimental data available. As this study is not a standard information requirement in REACH and there is no indication from the CSA on the need to investigate further the fate and behaviour of the substance (Annex X requirement), no further testing is considered necessary.

Phototransformation in soil:

No experimental data available. As this study is not a standard information requirement in REACH and there is no indication from the CSA on the need to investigate further the fate and behaviour of the substance (Annex X requirement), no further testing is considered necessary.

Biodegradation:

Biodegradation in water : screening test

No. of studies of target substance N,N-dimethylaniline reviewed for Biodegradation in water: screening tests from reliable sources having Klimisch rating 2 & 4.

The summary of the results are presented below

Sr no.	Endpoint	Half life	Parameter	Sources	Result
1.	Ready biodegradability	38 days	Half life	Predicted data from PBT profile	Ready biodegradable
2.	Ready biodegradability	1.3 hours	50% Biodegradation	publication	Ready biodegradable
3.	Ready biodegradability	28 days	75% biodegradation	publication	Ready biodegradable
4.	Ready biodegradability	1.4 hrs	50% Biodegradation	Publication RA CAS 91-66-7	Ready biodegradable

 

Considering the weight of evidence approach and studies reviewed for target chemical N,N-dimethylaniline and read-across chemical N,N-diethylanilineit is concluded that the N,N-dimethylaniline is readily biodegradable in nature.Thus this also confirmed thatthe N,N-dimethylaniline is not persistent in nature.

Biodegradation in water and sediment: simulation tests:

Based on the Level III Fugacity Model, the half life period of N, N-dimethylaniline was estimated. Half life period of N, N-dimethylaniline in water is observed to be 37.5 days (900 hrs.) while in sediment it is 337.5 days (8100 hrs.).Based on these half life values of N, N-dimethylaniline, it is concluded that the chemical is readily biodegradable in water where as it is non biodegradable in sediment. However, since there is very less diffusion of the substance in the sediment as evident from the reported data (0.141% in sediment) and hence persistence in the sediment compartment is not likely to be critical.

Biodegradation in soil:

The PBT Profiler & EPI Suite has estimated that N, N-dimethylaniline is expected to be found predominantly in soil and its persistence estimate is based on its availability in this medium. Its half-life in soil is 1800 hrs (75 days). This exceeds the EPA criteria of >= 60 days and therefore, N, N-dimethylaniline is estimated to be persistent in the soil environment.

Bioaccumulation:

Bioaccumulation: aquatic / sediment:

No. of studies of target substance N,N-dimethylaniline reviewed for bioaccumulation from reliable sources having Klimisch rating 2.

The summary of the results are presented below

Sr no.	Endpoint	Value	result	Sources
1.	BCF	16	non bioaccumulative	Predicted data from PBT profiler
2.	BCF	15.53 L/kg	non bioaccumulative	Predicted data from EPI Suite
3.	BCF	10.1 L/kg wet wt. at concentration of 0.05 mg/L and 13.6 L/kg wet wt. at concentration 0.5 mg/L.	non bioaccumulative	CSCL Japan

 

By applying weight of evidence approach the target chemical N,N-dimethylaniline found to be non bioaccumulative with BCF value 10.1 L/Kg to 16 L/Kg which is not expected to bioaccumulate in the food chain because it does not exceed the BCF criteria of 2000. 

Transport and distribution:

Adsorption/ desorption:

Soil Adsorption Coefficient i.e Koc value of N,N-dimethylaniline was estimated as 78.67 L/kg by means of MCI method. This value is equivalent to 62.936 at 20°C. These values indicate that the substance will have low sorption capacity to soil and sediment with moderate migration potential with the water fraction found in the sediments.