1,4-Dioxane (CAS 123-91-1): storage and disposal

Highly flammable vapour and a cancer classification together decide its place: a ventilated fire-resistant cabinet with spill containment, with access limited to those who need it. Avoid the coldest corner of an unheated store, because a frozen bottle conceals crystals and gives a false impression of its condition. Permanganate, dichromate, chlorate, hypochlorite, chromium trioxide and hydrogen peroxide belong well away, as this ether can ignite or explode with them. Write the opened date on the label and review an opened bottle at 12 months. A histology bench may still have an old dehydrant bottle left from earlier methods, so include those benches when checking stock. Eye and airway irritation mean a poor cap should not simply be lived with until the next review.

Often the first thing noticed is a bottle that has gone solid in a cold store, and freezing itself is normal for dioxane. The problem is what it hides, since any crystals of peroxide cannot be told from frozen solvent. A liquid bottle gives few visual signs too, and it can stay clear while peroxides build. So the opened date counts for more than appearance. Look for crystals around the cap, a viscous layer, a failed seal or a faded label. Nobody should warm a frozen bottle to see what is inside. If it is old, undated or shows warning signs, do not move it, do not open it, and get a specialist assessment. Any peroxide testing is for competent staff only.

Forms explosive peroxides on storage.

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.

A frozen or old bottle must not be thawed, opened or carried to a better spot before advice comes, and none of this stock goes into a sink or drain. Nobody should try to make it safe first either. It is not quoted online, and it is not accepted through the online quote path, since age cannot be judged from a web form. Your enquiry should say whether it is liquid or solid at the time, what the dates show, and which bench or store it sits in. A store assessment is recommended, with a competent chemist or, if warning signs are present, an explosives or emergency specialist. A hospital histology department normally uses code 18 01 06* for it, rather than 16 05 06*.

Usually held as: neat.

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.