Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:
no hazard identified

Sediment (marine water)

Hazard assessment conclusion:
no hazard identified

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

Substance is a gas and is extremely unlikely to reside in the aquatic or terrestrial compartment. Deriving a PNEC for a gas is unreasonable and technically of little use for risk assessment as the substance will not be present in the aquatic or terrestrial environment.

Conclusion on classification

The lowest calculated acute result was a 96 hr EC50 for green algae of 57 mg/L. A log Kow of 0.37 for acetylene indicates the potential for bioaccumulation to be low. Measured data are not available to demonstrate that acetylene is readily biodegradable, but it is expected to partition to the air from water, reducing the potential for exposure. Volatilisation from surface waters will predictably be rapid: Henry's Law constant indicates that the volatilisation half life will be <6 days in a water body up to10 metres deep. EPISuite QSAR model predicts half-lives of 32 minutes and 49 hours in rivers and lakes respectively (1m depth, wind velocity 5 and 0.5 m/sec respectively). If released into surface waters, volatilisation will therefore ensure rapid removal of acetylene into the atmospheric compartment. Furthermore, based on Pedersen et al (1995) this rate of volatilisation is equivalent to a substance being readily biodegradable. On these grounds, classification for aquatic toxicity is not considered to be warranted