Guanidine thiocyanate (CAS 593-84-0): storage and disposal
In university and pathology labs, guanidine thiocyanate is the corrosive solid and the active part of RNA lysis buffer used in nucleic acid extraction. Stock is held as powder and as ready-made lysis buffer. The recorded hazards are harm by swallowing, skin contact and inhalation, severe skin burns and eye damage, and the rule that matters most is to keep it away from bleach and acids.
- CAS number
- 593-84-0
- Form
- Solid
- Storage class
- Corrosive
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
Corrosive
Harmful or irritant
What to do this week
- Check the label is readable and write down the opened date if it is not already there.
- Check it is stored as corrosive stock and apart from the items listed under "Do not store with".
- 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
At a university molecular biology bench, the stock usually sits low down in a corrosive store with the lysis buffer bottles, and the first question is what is beside it. Bleach and acids can release toxic gases from this chemical, including hydrogen cyanide, so keep both on a separate shelf and make sure a bleach wash bottle is never stood next to it on a bench or trolley. Corrosive stock also stays away from flammable materials, because a leak can break down their containers, and from oxidisers, which can react with it. Use a resistant tray, close the cap fully and label the opening date on both powder and buffer.
How to tell it has deteriorated
Normal stock is a colourless to white crystalline solid that is highly moisture-absorbing, so the thing that changes first is the powder itself. It clumps, turns wet and may become a sticky mass inside the bottle. Damp stock corrodes metal caps and rack fittings, leaving crust on the thread and staining on the shelf. Lysis buffer bottles may show crystals around the cap or a label that has softened where drips have run. Do not open a bottle to check if the cap is crusted shut. A bottle that is wet, weeping, or stored near bleach or acid should be recorded and left until the collector has been told.
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.
Start with the code, 16 05 06* in a research setting, 16 05 08* for a discarded organic chemical outside a pack, or 18 01 06* in human healthcare, and write which applies. Describe separately the dry powder and each lysis buffer bottle, with the label wording and approximate volume. Lysis waste must be kept separate from bleach at every stage, because bleach or acid contact can release toxic gases including hydrogen cyanide. Bottles go upright into a lab pack for specialist collection by a registered carrier. Nobody should add bleach to used lysis buffer to deal with it, and it must never go to a sink or drain.
| EWC code, laboratory chemicals | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| Human healthcare setting | 18 01 06* |
| Hazardous waste | Yes |
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: solid, RNA lysis buffer.
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
- H302 Harmful if swallowed.
- H312 Harmful in contact with skin.
- H314 Causes severe skin burns and eye damage.
- H332 Harmful if inhaled.
- H412 Harmful to aquatic life with long lasting effects.
Precautionary statements
- 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.
- 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+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.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- P363 Wash contaminated clothing before reuse.
- 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 must lysis waste never meet bleach?
Contact with bleach or acids can release toxic gases, including hydrogen cyanide. Lab clean-up often uses bleach, so keep spill kits, wash bottles and lysis waste apart. Collect used buffer separately in a labelled container.
Can we dispose of used RNA lysis buffer with other waste liquid?
No. It must stay separate from bleach and from acids, and it should not be bulked with other liquids. Keep it in its own labelled bottle so the collector can describe and group it correctly.
The powder has gone wet. What should we do?
Leave it closed, place the bottle in a resistant tray away from bleach and acids, and record it. Wet stock is corrosive and attacks caps and shelving, so it is for collection and not for further use.
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