Cenovus is reporting a spill of synthetic drilling mud from the West White Rose platform on Thursday.

The company says the 1,400 litre spill occurred about 63 metres below sea level, and no sheen was noticed on the sea surface from the platform or a standby vessel which conducted a sweep of the area.

Operations were suspended as a precaution, and Cenovus conducted an investigation into the circumstances surrounding the spill.

Operations resumed on Friday.

Offshore regulator, the C-NLOER says the mud has very low toxicity and can break down with enough exposure to oxygen.

Because it is heavy, it generally sinks and settles on the bottom.