Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

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

Marine water

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

STP

Hazard assessment conclusion:
no data available: testing technically not feasible

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:
no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Assessment factors for aquatic PNECs taken from ECHA "Guidance on information requirements and chemical safety assessment, Chapter R.10: Characterisation of dose [concentration]-response for environment", May 2008. Default values used for a substance for which there is acute toxicity data for three trophic levels, but for which long-term toxicity data are not available.

Conclusion on classification

On the basis of the available acute ecotoxicological data it was noted that fish were the most sensitive species, with a 96 -hour LC50 value of 4.3 mg/L. According to the CLP Regulation (Regulation (EC) 1272/2008, as adapted for technical and scientific progress by Regulation (EC) 286/2011, the second ATP to the regulation), BTP does not meet the classification criteria for an acute (short-term) aquatic hazard.

BTP was found not to degrade in the water compartment by either biotic (biodegradation) or abiotic (hydrolysis) routes. The calculated Henry's law constant (H) for BTP is 14350 Pa.m^3/mol; on the basis that H is greater than 100 Pa.m^3/mol it is expected that more than 50% of the substance will be lost from the water phase between 3 and 4 hours, i.e. BTP will partition extensively to air and will not persist within the aquatic environment. In the air / atmospheric compartment BTP is expected to react with gas phase OH radicals and degrade abiotically (refer to Journal of Geophysical Research, vol 116, 2011); the calculated atmospheric lifetime for latitudes relevant to use within Europe (30°N to 60°N) is 7.0 days and as such BTP is expected not to persist within the environment.

On this basis the substance is not considered to meet the criteria for classification as a chronic hazard to the aquatic environment.