Remember that RSM chemical spill that sent three people to the hospital earlier in March? Turns out the culprit was escaped hydrochloric acid fumes generated by the polymerisation of a forgotten container of acryloyl chloride, according to an email circulated by Eddie Hartrick, Process Safety Officer.

According to Hartrick’s email this is the second incident of this nature, involving this particular substance, in the last 18 months.

“If left in storage for a long time (even in the fridge and at the correct temperature) it can polymerise in the bottle,” explains Hartrick in his email. “This generates HCl gas and increases the pressure in the bottle until it leaks. As it is stored in a fridge there is no chance that the fumes will be extracted. Acryloyl chloride is fatal if inhaled and is also a lachrymator (induces tears), making it difficult to clean up and generally deal with safely in the case of a leak.

The March incident was a result of a bottle put in the fridge by a PI who has now left the department. The bottle was forgotten, ultimately leading to the polymerisation of the acryloyl chloride contained within and the release of hydrochloric acid fumes. Staff has been advised to check fridges and ensure the disposal of any forgotten/unused acryloyl chloride.

The same advice has been issued with stores of Acryloyl chloride (contains MEHQ as stabiliser), Acryloyl chloride (contains phenothiazine as stabiliser), Acryloyl chloride, Methacryloyl chloride, Methacryloyl chloride (contains 2,6-di-tert-butyl-4-methylphenol as stabiliser) and Methacryloyl chloride (contains monomethyl ether hydroquinone as stabiliser). Catchy names, I’m sure you’ll agree. A College spokesperson told felix that Imperial has revised its procedures in light of the incident. “The chemical will be substituted with an alternative where possible, and Acryloyl Chloride no longer be stored long-term.”

Keep track of your chems kids.