Tetrahydrofuran (CAS 109-99-9): storage and disposal

Stabilised and unstabilised bottles look alike on a university shelf, so read the supplier label and mark which is which, as that decides how fast it ages. Stabiliser-free grades bought for instrument work are the ones to watch. Each should carry an opened date, with a review at 12 months for any bottle, and sooner in practice if it is unstabilised. Keep it in a ventilated fire-resistant cabinet with spill containment, away from nitric and perchloric acids, permanganate, dichromate, chlorate and hypochlorite, since it can ignite or explode with such partners. Septum-capped bottles that have been pierced many times let air in, so they count as opened however full they appear. Only a spark-free refrigerator should hold any chilled stock.

Check the cap first: THF softens many plastics, so a swollen, tacky or deformed liner on an old bottle says the seal can no longer be trusted. The label should show an opened date, and its absence is itself a warning. Crystals at the cap or in the liquid, a viscous layer and an old bottle with no date all mean do not open or move it. Liquid can stay clear and colourless while peroxides build up, so a clean look gives no comfort once the stabiliser has gone. Get a specialist assessment for any of these. Testing is for competent staff only, on bottles that are in date, and never on one that shows crystals or a viscous layer.

Forms explosive peroxides once its stabiliser is used up.

This can form peroxides as it ages, especially after opening. Age and the opened date matter more than appearance, so a container with no opened date should be treated as old.

Review after 12 months: Review interval after opening from the cited peroxide former lists, not an expiry date from a manufacturer. Class C and all other chemicals are left null.

This does not go through our standard collection route. It is arranged by manual enquiry, and never goes down the drain or into general waste.

Nobody should open a suspect bottle to see how it looks, and it must never go into a sink or drain. Leaving it uncapped to disappear is forbidden too, as that would concentrate any peroxides present. Online quoting does not apply: THF is not accepted through the online quote path because age cannot be judged from a web form. Send a manual enquiry saying whether the bottle is stabilised or stabiliser-free, what the opened date shows, and how full it seems from the outside. Pierced septum bottles should be mentioned separately. A store assessment is recommended, with a competent chemist deciding in person, or an explosives or emergency specialist if warning signs are present. It normally takes code 16 05 06* once it is cleared to travel.

Usually held as: neat, stabilised.

Part-used bottles and full containers are both fine. Tell us the size and how many, and an estimate is enough for a first price.