Boric acid (CAS 10043-35-3): storage and disposal
Boric acid is held as a white powder or crystals in school and college prep rooms, university labs, histology stores and pharmacies. It is classified as one that may damage fertility and may damage the unborn child. It looks like any other white solid and is often an old, half-forgotten jar, so a locked store, a stock record and a clear label decide how it is handled.
- CAS number
- 10043-35-3
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Serious health hazard
What to do this week
- Without moving anything that looks damaged, check the label is readable and write down the opened date if it is not already there.
- Check it is stored as toxic stock, and apart from anything listed under "Do not store with" on this page. If nothing is listed, that does not prove it is safe with everything.
- If you no longer need it, add it to your disposal list so it can be included in a collection.
Safe storage in a school or lab
A screw-cap jar of white crystals or powder is the usual form, and it belongs in a locked cabinet with a stock record because of the reproductive hazard. It should sit away from food and drink areas and from acids and oxidisers, which means it cannot go on an acid shelf just because its name includes acid. In a school prep room or a pharmacy it is easily moved to a general shelf in a clear-out, so the cabinet and the record are the protection. Anyone handling it who is or may be pregnant should be told what it is.
How to tell it has deteriorated
A dry, loose, white solid is what normal looks like, and boric acid gives few visible signs of age. The faults are around it. Look for a faded label, staining around the cap, a failed seal, caking or clumping from damp and, most commonly, a missing stock record. A jar that has no record is itself a warning, because nobody knows how old it is or who has opened it. An unexpected colour or a jar with no label should be left closed in the locked cabinet and listed for collection with a description of what can be seen.
How it is disposed of
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 We do not publish a drain or general waste route for any chemical.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 toxic laboratory pack with compatible chemicals.
Specialist collection is the only way it goes. Say on the booking that it may damage fertility and the unborn child, because the people packing the load need to know. It is inorganic, so a jar outside a lab pack would usually be coded 16 05 07*. It must never be tipped into a sink or drain, or put in a bin or skip, and it must not be dissolved or neutralised first. Record the amount, the container and whether the stock record can be found. The collector keeps it with other toxic solids and away from acids and oxidisers, which is how it should have been stored too.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded inorganic chemical, not a laboratory pack | 16 05 07* |
| Human healthcare setting | 18 01 06* |
| Usually classed as hazardous waste | Yes |
The code depends on where the waste came from and what it contains, and classifying it is the producer's duty. Use the waste code finder to see why.
Do not store with
- OxidiserToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- AcidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Named chemicals to keep apart
- Acetic acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Calcium hypochloriteToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Hydrochloric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Hydrogen peroxideToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Nitric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Potassium nitrateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Potassium permanganateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Sulfuric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Common quantities
Usually held as: solid.
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.
Where it is commonly held
Hazard statements
- H360FD May damage fertility. May damage the unborn child.
Precautionary statements
- P203 Obtain, read and follow all safety instructions before use.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P318 If exposed or concerned, get medical advice.
- P405 Store locked up.
- P501 Dispose of contents and container in accordance with local, regional, national and international regulations.
Substance as classified, dilutions may differ.
Questions
Why is boric acid kept in a locked cabinet when it has acid in its name?
The classification that matters is that it may damage fertility and the unborn child, so it is stored as toxic stock with a stock record, not on the acid shelf. Keep it away from food areas, acids and oxidisers.
How do we deal with an old jar with no stock record?
Leave it closed in the locked cabinet, note what the label says and what the jar looks like, and add it to the collection list. Do not open it to check, and tell the booking team the record is missing.
Does it matter if the powder has gone lumpy?
Lumps suggest damp has got in, which means the lid or seal is failing. It does not change the hazard. Keep the jar closed, check the seal and label, and list it for collection if it is old or unrecorded.
