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Chemical collection and stock control for UK schools, universities and hospitals

Tin(II) chloride (CAS 7772-99-8): storage and disposal

Tin(II) chloride dihydrate, also called stannous chloride, is kept in school, college and university stores and in histology labs where it is used in staining. It is classified as causing severe skin burns and eye damage, as possibly corrosive to metals, as a skin sensitiser, as harmful if swallowed or inhaled, as possibly causing organ damage with repeated exposure and as very toxic to aquatic life. It is also easily altered by air.

CAS number
7772-99-8
Form
Solid
Storage class
Corrosive
Signal word
Danger
Usual EWC code
16 05 06*
  • Corrosive pictogramCorrosive
  • Harmful or irritant pictogramHarmful or irritant
  • Serious health hazard pictogramSerious health hazard
  • Hazardous to the environment pictogramHazardous to the environment

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as corrosive stock and apart from the items listed under "Do not store with".
  3. If you no longer need it, add it to your disposal list so it goes on the next collection.

Safe storage in a school or lab

Keep oxidisers away from it. Tin(II) is a reducing agent, so an oxidiser on the next shelf is a reaction waiting for a leak, as well as the usual corrosive concern. Put it low down on a resistant tray in a ventilated corrosive store, with plastic-lined caps, because it may be corrosive to metals and a metal cap or shelf will not last. Keep the lid tight, since air and moisture change the solid. Histology stores that hold made-up solution should label it separately with the date, because a solution kept on a shelf goes cloudy. The date received goes on every jar.

How to tell it has deteriorated

Air and water do the damage here. The white crystals slowly oxidise, and a jar that has been opened often develops a hard, clumped surface with a sour smell of hydrogen chloride. Stannous chloride solutions go cloudy and leave a white deposit because the salt reacts with water and air, which means a histology bottle with a white sediment has changed from what the label says. Look for corroded cap threads, etched shelf surfaces and crystals stuck to the glass. A faded label or a jar with no date should be flagged straight away.

How it must be disposed of

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a corrosive other laboratory pack with compatible chemicals.

Pack it as corrosive stock, upright in a tray, and keep it separate from oxidisers in the collection. The code is 16 05 06* in a laboratory pack, 16 05 07* for discarded inorganic stock outside one, and 18 01 06* in a human healthcare setting such as a hospital histology lab. UN 3260 is the transport entry. Describe the solid and any made-up solution separately, noting whether the solution is cloudy or has a deposit. It must never go into a drain or the ordinary bin, and nobody should try to clear a cloudy bottle or neutralise it. Request a specialist collection.

Waste codes and transport details for Tin(II) chloride
EWC code, laboratory chemicals16 05 06*
Discarded inorganic chemical, not a laboratory pack16 05 07*
Human healthcare setting18 01 06*
Hazardous wasteYes

The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.

Do not store with

  • FlammableA leak of corrosive stock can break down flammable containers and feed a fire.
  • OxidiserCorrosive stock can react with oxidisers, releasing heat or fumes.

Named chemicals to keep apart

  • AcetoneA leak of corrosive stock can break down flammable containers and feed a fire.
  • Calcium hypochloriteCorrosive stock can react with oxidisers, releasing heat or fumes.
  • EthanolA leak of corrosive stock can break down flammable containers and feed a fire.
  • HexaneA leak of corrosive stock can break down flammable containers and feed a fire.
  • Hydrogen peroxideCorrosive stock can react with oxidisers, releasing heat or fumes.
  • MethanolA leak of corrosive stock can break down flammable containers and feed a fire.
  • Potassium nitrateCorrosive stock can react with oxidisers, releasing heat or fumes.
  • Potassium permanganateCorrosive stock can react with oxidisers, releasing heat or fumes.
Show 1 more
  • TolueneA leak of corrosive stock can break down flammable containers and feed a fire.

Common quantities we collect

Usually held as: dihydrate.

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.

Where it is commonly held

Hazard statements

  • H290 May be corrosive to metals.
  • H302 Harmful if swallowed.
  • H314 Causes severe skin burns and eye damage.
  • H317 May cause an allergic skin reaction.
  • H332 Harmful if inhaled.
  • H335 May cause respiratory irritation.
  • H373 May cause damage to organs through prolonged or repeated exposure.
  • H410 Very toxic to aquatic life with long lasting effects.
Precautionary statements
  • P234 Keep only in original packaging.
  • P260 Do not breathe dust, fume, gas, mist, vapours or spray.
  • P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264 Wash hands and exposed skin thoroughly after handling.
  • P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
  • P270 Do not eat, drink or smoke when using this product.
  • P271 Use only outdoors or in a well-ventilated area.
  • P272 Contaminated work clothing should not be allowed out of the workplace.
  • P273 Avoid release to the environment.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • P301+P317 IF SWALLOWED: Get medical help.
  • P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
  • P302+P352 IF ON SKIN: Wash with plenty of water.
  • P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
  • P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
  • P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P316 Get emergency medical help immediately.
  • P317 Get medical help.
  • P319 Get medical help if you feel unwell.
  • P321 Specific treatment (see supplemental first aid instruction on this label).
  • P330 Rinse mouth.
  • P333+P317 If skin irritation or rash occurs: Get medical help.
  • P337+P317 If eye irritation persists: Get medical help.
  • P362+P364 Take off contaminated clothing. And wash it before reuse.
  • P363 Wash contaminated clothing before reuse.
  • P390 Absorb spillage to prevent material damage.
  • P391 Collect spillage.
  • P403+P233 Store in a well-ventilated place. Keep container tightly closed.
  • P405 Store locked up.
  • P406 Store in corrosive resistant container with a resistant inner liner.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

Why has our tin(II) chloride solution gone cloudy?

The salt reacts with water and air, leaving a white deposit. The bottle no longer matches its label. Do not try to clear it. Keep it closed, record the cloudiness and include it in the collection.

Why must it be kept away from oxidisers?

Tin(II) is a reducing agent and the stock is classified as corrosive. An oxidiser nearby could react with it if there is a leak. Use a separate resistant tray in the corrosive store.

Which waste code applies in a histology lab?

In a hospital, a human healthcare setting uses 18 01 06*. A laboratory pack uses 16 05 06*, and discarded inorganic stock outside one uses 16 05 07*. State your setting when you ask for collection.

Why do the caps and shelves corrode?

The classification says it may be corrosive to metals, and the salt can give off hydrogen chloride when damp. Use plastic-lined caps, a resistant tray and a ventilated corrosive store.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula Cl2Sn. EC number 231-868-0.

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