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

n-Butyllithium (CAS 109-72-8): storage and disposal

Sold as a 2.5 M solution in hexanes, n-butyllithium is an organolithium reagent found in university synthetic chemistry groups, in a sealed bottle under inert gas. It catches fire on contact with air and gives off flammable gas with water, so this site handles it by enquiry and not through an online quote. The state of the seal, any solids in the bottle and the age of the stock decide what happens next.

CAS number
109-72-8
Form
Solution
Storage class
Flammable
Signal word
Danger
Usual EWC code
16 05 06*
  • Flammable pictogramFlammable
  • Corrosive pictogramCorrosive

This chemical is a manual enquiry

This can become unstable or explosive, especially if it is old or has dried out. Nobody should move it until someone competent has looked at it, so we start with a conversation and usually a store assessment.

Ignites in air on contact.

It cannot be priced through a form. Please do not open or move it. Call us or send an enquiry and we will talk through the safe next step, which is often a store assessment.

What to do this week

  1. Leave it where it is. If it looks old, crystalline or damaged, do not open or move it and keep people away from the shelf.
  2. Write down the label wording, the rough age and where it is stored, from a safe distance.
  3. Send us those details, and a photo if you can take one without touching it.

Safe storage in a school or lab

Oxidisers, acids and corrosive stock all need to stay well away, because any of them can start or feed a fire around a bottle whose contents already ignite in air. Water is the other problem: contact releases flammable gas that may light by itself, so a damp shelf or a wet bench is the wrong home. Research groups normally keep the bottle in a ventilated fire-resistant cabinet with spill containment, or in a spark-free refrigerator if cold storage is needed. The inert gas above the liquid is what protects it, and every needle hole in the septum weakens that protection. If you find a bottle somewhere unsuitable, leave it where it is and ask for advice first.

How to tell it has deteriorated

A perished septum, a loose or corroded cap, a torn outer seal and a faded or missing date are the first things to look for. Bottles in regular use often carry a septum pierced many times over, and each hole lets in a little air and moisture. Solids in the bottle are the plain warning: air, moisture and slow decomposition leave lithium compounds that do not stay dissolved. A falling liquid level suggests lost hexanes, which leaves a stronger solution behind. Strength can also fall with no outward change, so a clear liquid proves little. Do not open or move a bottle showing any of these. Fuming or charring at the neck is a warning sign that may need an emergency specialist.

How it must be disposed of

This does not go through our standard collection route. It is arranged by manual enquiry, and never goes down the drain or into general waste.

Never pour it into a sink or drain, never put it in a bin or skip, and do not quench the remainder yourself, however little is left in the bottle. This site does not quote for n-butyllithium online, and it cannot be booked through the online quote path. Send a manual enquiry instead, and expect a store assessment to be recommended. A competent chemist needs to look at it in person, and a warning sign may bring in an emergency specialist. The enquiry is most useful when it gives the concentration on the label, the solvent, roughly how much remains, when the bottle was first pierced and the condition of the septum. Do not open it, move it or try to make it safe while you wait.

Waste codes and transport details for n-Butyllithium
EWC code, laboratory chemicals16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
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

  • OxidiserOxidisers can ignite flammable materials or make a fire far more intense.
  • AcidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • CorrosiveA leak of corrosive stock can break down flammable containers and feed a fire.

Named chemicals to keep apart

  • Acetic acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Calcium hypochloriteOxidisers can ignite flammable materials or make a fire far more intense.
  • Hydrochloric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Hydrogen peroxideOxidisers can ignite flammable materials or make a fire far more intense.
  • Nitric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Potassium nitrateOxidisers can ignite flammable materials or make a fire far more intense.
  • Potassium permanganateOxidisers can ignite flammable materials or make a fire far more intense.
  • Sulfuric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
Show 2 more
  • Thionyl chlorideA leak of corrosive stock can break down flammable containers and feed a fire.
  • Zinc chlorideA leak of corrosive stock can break down flammable containers and feed a fire.

Common quantities we collect

Usually held as: 2.5 M in hexanes.

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

  • H250 Catches fire spontaneously if exposed to air.
  • H260 In contact with water releases flammable gases which may ignite spontaneously.
  • H314 Causes severe skin burns and eye damage.
Precautionary statements
  • P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P222 Do not allow contact with air.
  • P223 Do not allow contact with water.
  • P231 Handle and store contents under inert gas.
  • P231+P232 Handle and store contents under inert gas. Protect from moisture.
  • P233 Keep container tightly closed.
  • 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.
  • P272 Contaminated work clothing should not be allowed out of the workplace.
  • 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+P335+P334 IF ON SKIN: Brush off loose particles from skin. Immerse in cool water or wrap in wet bandages.
  • 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.
  • P333+P317 If skin irritation or rash occurs: Get medical help.
  • P362+P364 Take off contaminated clothing. And wash it before reuse.
  • P363 Wash contaminated clothing before reuse.
  • P370+P378 In case of fire: Use suitable extinguishing media to extinguish.
  • P402+P404 Store in a dry place. Store in a closed container.
  • 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

Can our group make a part-used bottle safe before anyone comes to look at it?

That is not something we suggest, and we give no method for it. Once a bottle is surplus, describe it in a manual enquiry and leave it as it stands. Attempting to make it safe before advice arrives is exactly what the assessment is there to avoid.

Does a bottle of butyllithium have to be kept in a refrigerator?

Not necessarily. Refrigeration depends on the supplier's storage requirements for the particular formulation. If refrigeration is specified, use suitable equipment for flammable solvents and maintain the required inert atmosphere. An ordinary domestic fridge is the wrong place, because the hexanes bring a flammable vapour risk. Condensation on a cold bottle also matters here, since water releases flammable gas from any reagent that reaches it.

A former researcher left an undated bottle in a cabinet. What should we do?

Leave it where it is and do not try to open it to see what is inside. Note what you can read on the label and what you can see from outside, including any solids or seal damage. Include those details in a manual enquiry so a competent chemist can assess it in person.

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 C4H9Li. EC number 203-698-7.

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