Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The data on atmospheric reactions suggests rapid photodegradation in air. The life time of AHTN is sufficiently short that it excludes long-range transport. In water, AHTN is degraded primarily via direct photolysis and not via reactive oxygen.

The major environmental exposure route of AHTN is via the sewage to the aquatic environment. Consequently, the environmental fate and pathway for this route is most relevant.

In the primary degradation processes, AHTN is rapidly transformed to polar metabolites.

In batch experiments with activated sludge spiked with radio-labelled AHTN, the half-life of the parent compound (AHTN) was less than 1 day and within 20 days AHTN was largely transformed to metabolites. In the river water die-away test the overall half-life was circa 9 days and the biological degradation after 28 days was 42%.

For the environmental risk assessment, AHTN may be considered as inherently biodegradable', not fulfilling criteria'.

It has been demonstrated that the bioconcentration factor is well below the first threshold of the bioaccumulation criteria. Hence, AHTN should not be regarded as a bioaccumulative substance.

Since the measured Koc/Kd values ranges widely, a calculated Koc based on the log Kow has been used for the environmental assessment. This Koc falls within the empirically determined Koc/Kd range.