Assertion: butadiene | /r/HasProperty | detected at 2 and 5 µg/litre
Facets:
value: only twice
type: TEMPORAL
Source sentences:
text: It was detected only twice, at 2 and 5 µg/litre, in 2103 compo site samples of aqueous effluent taken every 4 h in 1996 (detection limit 1 µg/litre).