Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
22.2 µg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
222 µg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
2.2 µg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
65 000 µg/L
Assessment factor:
1
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:
no exposure of sediment expected

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
2.95 µg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

The aquatic toxicity data for xylananse were obtained from short term toxicity studies in species representing three trophic levels (i.e. algae, crustaceans and fish). Xylanase was not toxic to aquatic organisms and the derived NOEC of 22.2 mg aep/L was used for PNEC derivation and the assessment factors 1000 and 10000 were applied for fresh and marine water, respectively.

The PNEC value for STP (sewage treatment plants)is based on actual measurements of enzyme concentration in STP connected to manufacturing site. Up to 65000 µg active enzyme protein were detected in STP connected to manufacturing site and since there was no negative impact observed, this concentration is the estimated PNEC value for STP.

PNEC values for sediment exposure have not been derived because xylanase is readily biodegradable, highly water soluble and has a very low potential for adsorption to sediments. Exposure of the sediment to toxicologically significant concentrations of the test substance is thus not expected.

As no soil ecotoxicity data are available for alpha-amylase, the PNEC for soil is based on the PNEC for surface water using the equilibrium partitioning method. PNEC soil was estimated to 2.61*10 -3mg aep/kg soil ww (wet weight) and PNEC for soil dry weight (dw) to 2.95*10-3 mg aep/kg soil dw.

Xylanase is not expected to cause any significant secondary poisoning as it is ready biodegradable and has no bioaccumulation potential. Furthermore, as xylanase is a protein it is expected to be degraded in the gastrointestinal tract. Thus PNEC oral is not relevant.

Conclusion on classification

Based on the aquatic toxicity studies and the ready biodegradation of the enzyme, xylanase is not classified.