Cadmium sulfate (CAS 10124-36-4): storage and disposal
Usually held as colourless or white crystals, cadmium sulfate is legacy stock in school, college and university stores, and it may also be sitting inside old electrical standard cells in a physics store. It is toxic if swallowed, fatal if inhaled, may cause cancer and genetic defects, and may damage fertility and the unborn child. Finding all of it, including forms not labelled as chemicals, decides how it should be handled.
- CAS number
- 10124-36-4
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Acute toxicity
Serious health hazard
Hazardous to the environment
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
Crystals in a screw top jar are the usual form, sometimes labelled as the monohydrate or simply as cadmium sulfate, and they look much like the copper free sulfates stored nearby. Check that the label says cadmium, then keep it on a dedicated tray inside a locked toxic cabinet with a stock record, not on the general salts shelf where alphabetical order may have put it. Acids and oxidisers are kept elsewhere, and food and drink stay out of the room. Physics stores can hold old standard cells containing this salt with mercury, and those belong to the same locked arrangement once found. A cell is sealed glass and easily broken, so it needs padding and a label, and the box must not be stacked or disturbed.
How to tell it has deteriorated
Look at the jar and its label before the crystals. On old stock, a corroded or perished lid and a label that has faded enough to lose the first word are the main faults, and a cadmium salt reading only as sulfate is a real problem. Beyond the container, it gives few visual signs of age. Crystals may turn cloudy or crumble as the water in them changes, which does nothing to the hazard. Caking points to damp. On a standard cell, look for a crack, a weeping seal or a stain in the box. Any white dust on the shelf should be reported and left alone. A gap in the stock record is worth fixing while somebody still remembers the item.
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.
A note of each container comes first: its label, any hydrate stated, how much is present and whether the lid is sound. Standard cells should be listed separately with their number and condition, and with a mention that they contain cadmium and mercury, because a glass cell is packed differently from a jar of salt. Compatible toxic solids go together in a lab pack, and acids and oxidisers do not join them. The usual code for a school or university is 16 05 06*. It leaves by specialist collection alone. There should be no attempt to rinse jars into a sink or drain, or to put them in a general waste bin or skip, and no treatment of any kind beforehand.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded inorganic chemical, not a laboratory pack | 16 05 07* |
| 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: legacy stock.
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
- H301 Toxic if swallowed.
- H330 Fatal if inhaled.
- H340 May cause genetic defects.
- H350 May cause cancer.
- H360FD May damage fertility. May damage the unborn child.
- H372 Causes damage to organs through prolonged or repeated exposure.
- H410 Very toxic to aquatic life with long lasting effects.
Precautionary statements
- P203 Obtain, read and follow all safety instructions before use.
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- P270 Do not eat, drink or smoke when using this product.
- P271 Use only outdoors or in a well-ventilated area.
- P273 Avoid release to the environment.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P284 In case of inadequate ventilation wear respiratory protection.
- P301+P316 IF SWALLOWED: Get emergency medical help immediately.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P316 Get emergency medical help immediately.
- P318 If exposed or concerned, get medical advice.
- P319 Get medical help if you feel unwell.
- P320 Specific treatment is urgent (see supplemental first aid instruction on this label).
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P391 Collect spillage.
- P403+P233 Store in a well-ventilated place. Keep container tightly closed.
- 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
We have old standard cells in the physics store. Could they contain this?
Yes, some old standard cells contain cadmium sulfate solution along with mercury. Do not dismantle them or tip them to look. Pad and label the box, record how many there are and whether any have cracked, and list them separately when asking for a collection.
Our label reads only sulfate after the top has faded. How do we describe it?
Describe it as partly legible and copy exactly what can be read. Say where it was stored and which bottles stood nearby. Do not test it or guess at the name, as an accurate description of an unknown is more useful than a wrong identification.
Can it wait on the normal salts shelf until it is collected?
No. A cadmium salt rated fatal if inhaled and able to cause cancer needs a locked toxic cabinet and a stock record, even for a short wait. Move an intact jar there with care and keep it on a tray until the collection.