Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Spent liquor from semi-chemical pulping (SCP liquor) is a UVCB substance with a fluctuating composition. Therefore the properties of individual substances may be somewhat variable. The biodegradability of two representative SCP liquor samples was tested by the Seibersdorf Labor GLP laboratory during 2009-2010 (the Key studies). For the other endpoints of environmental fate no data was found through extensive literature searches.

According to the test results there was a small difference between the samples. The other sample passed the ready biodegradability criterium (70%) clearly (81%, 28d) and the other sample slightly failed (68.1%, 28d), showing in any case obvious inherent biodegradability.

By overall estimation of the results it is concluded that SCP liquor can be regarded as readily biodegradable despite of the small discrepancy in the results. No other information of biodegradability was available.

SCP liquor consists of organic and inorganic substances extracted from the wood raw material and of process chemicals. The organic fraction is mostly of natural origin and is expected to be inherently degradable. The main inorganic constituents (mainly sodium salts) carry no harmonized class for environmental hazard and are not expected to be hazardous to the environment in diluted form.