Tin(II) fluoride (CAS 7783-47-3): storage and disposal

In a university chemistry store the jar usually ends up on a general shelf among the inorganic salts, which is acceptable only if it is labelled, dated and kept out of reach of casual handling. Serious eye damage is the hazard to plan around, so goggles belong beside the shelf and the container should never be decanted into unlabelled pots. In a dental surgery the bulk powder wants a separate spot from finished patient products, with a stock record, and well away from food and drink areas. Tin in this compound slowly oxidises, so keep the container tightly closed and dry, and keep it away from acids, because fluorides can release hydrogen fluoride on contact with strong acid.

Fresh powder is white and free flowing. What a technician sees first on an old jar is caking, a dull yellowish or grey tint, or hard lumps that no longer break up. Tin in the compound oxidises over time, and damp speeds that along, so a jar that has been opened often or kept somewhere humid shows it soonest. Other things to check are a label faded beyond reading, powder stuck in the thread of the cap and a jar with no record of its receipt. There are few dramatic signs with this solid. Anything that is changed in colour, wet or unlabelled is recorded as such and left closed.

We arrange this by specialist collection. We do not publish a drain or general waste route for any chemical. It is normally packed in a general laboratory pack with compatible chemicals.

Before asking for a collection, write down what the container actually carries: the name as labelled, roughly how much remains, whether it is still sealed and where it was held. A dental surgery or other human healthcare setting normally uses 18 01 06*, while a university store normally uses 16 05 06*, though the producer classifies the waste. It is packed with compatible solids in a lab pack. Washing the powder away, adding it to clinical waste or trying to make it safe on site are all ruled out. Specialist collection is the only way it leaves.

Usually held as: dental preparations.

Tell us the container size and how many you hold. An estimate is enough to start with, and some items cannot be priced until someone has looked at them.