Dichloromethane (CAS 75-09-2): storage and disposal
Dichloromethane arrives as a neat volatile liquid in school, college and university stores, often in glass or coated bottles. It is classified as a skin and eye irritant, may cause drowsiness or dizziness and is suspected of causing cancer. It passes through common glove types quickly and builds pressure in warm stores. Those two practical facts decide how it is handled far more than its label alone.
- CAS number
- 75-09-2
- Form
- Liquid
- Storage class
- Toxic
- Signal word
- Warning
- Usual EWC code
- 16 05 06*
Harmful or irritant
Serious health hazard
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 toxic 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
A bottle of dichloromethane tends to arrive in a coated glass container, and it belongs in a locked cabinet with a stock record, away from food and drink areas and cool rather than warm, since it builds pressure in warm stores. Keep it well clear of sodium metal, potassium metal, lithium metal and sodium azide: alkali metals can react explosively with chlorinated solvents, and azides can form explosive azidoalkanes with halogenated solvents. Prep rooms that still hold a metals cupboard should keep the two on opposite sides of the room, with a note on each cabinet.
How to tell it has deteriorated
Check the bottle for pressure first. A hissing cap, a visibly bulging or domed lid, or a distorted container can indicate increased internal pressure, particularly in a warm store. Leave a suspect bottle undisturbed and arrange specialist assessment before handling it. Look at the level, since a loss from the label mark shows a poor seal. This solvent also attacks some plastics and rubber seals, so softened liners are common. A cabinet shelf with stained or tacky patches should be reported, not wiped bare-handed, because gloves give little protection.
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 toxic laboratory pack with compatible chemicals.
Its waste code in our list is 16 05 06*, and a loose discarded organic chemical not in a pack can use 16 05 08*. What matters more is that nothing is added to the bottle: it is never combined with alkali metals or azides, never poured away, never left to evaporate, and nobody should try to treat it. Specialist collection is the only route, grouped with compatible halogenated solvents. Note bottle size, remaining volume and any pressure or closure fault so that the collector can plan handling, and keep the bottle cool until then.
| EWC code, laboratory chemicals | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| 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
- 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.
- Lithium metalAlkali metals can react explosively with chlorinated solvents.
- Nitric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Potassium metalAlkali metals can react explosively with chlorinated solvents.
- Potassium nitrateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
Show 4 more
- Potassium permanganateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Sodium azideAzides can form explosive azidoalkanes with halogenated solvents.
- Sodium metalAlkali metals can react explosively with chlorinated solvents.
- Sulfuric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Common quantities we collect
Usually held as: neat.
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
- H315 Causes skin irritation.
- H319 Causes serious eye irritation.
- H336 May cause drowsiness or dizziness.
- H351 Suspected of causing cancer.
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.
- 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.
- P301+P317 IF SWALLOWED: Get medical help.
- P302+P352 IF ON SKIN: Wash with plenty of water.
- 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.
- P319 Get medical help if you feel unwell.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P332+P317 If skin irritation occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- P403+P233 Store in a well-ventilated place. Keep container tightly closed.
Substance as classified, dilutions may differ.
Questions
Why is our dichloromethane bottle bulging?
Dichloromethane is volatile and builds pressure in warm stores. Leave the bottle upright on a tray in a cool place, do not open it and tell the collector about the bulge when booking.
Are ordinary lab gloves enough for dichloromethane?
It passes through common glove types quickly, so ordinary disposable gloves give little protection if it is spilt. Check your risk assessment for suitable gloves and treat any skin contact as a reason to wash immediately.
Can it be stored beside sodium metal?
No. Alkali metals can react explosively with chlorinated solvents, and sodium azide can form explosive azidoalkanes with halogenated solvents. Keep it in a separate cabinet, ideally on the far side of the room.
