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

Pyridine (CAS 110-86-1): storage and disposal

Pyridine usually arrives as a neat liquid in a glass bottle and goes straight into the solvent cabinet of a college or university lab. It is highly flammable, harmful by swallowing, skin contact and inhalation, and has a strong unpleasant smell that gives away a bad seal. A smell outside the cabinet is often the first sign anything is wrong.

CAS number
110-86-1
Form
Liquid
Storage class
Flammable
Signal word
Danger
Usual EWC code, laboratory stock
16 05 06*
  • Flammable pictogramFlammable
  • Harmful or irritant pictogramHarmful or irritant

What to do this week

  1. Without moving anything that looks damaged, check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as flammable 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.
  3. 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

Glass bottles of pyridine go into the ventilated fire-resistant cabinet with spill containment, away from ignition sources and oxidisers. Keep pyridine away from calcium hypochlorite, sodium hypochlorite, chloramine T and sodium dichloroisocyanurate because these oxidising chemicals can react dangerously with it. Acids, and any corrosive stock whose leak could attack a flammable container, belong on another shelf. Because the odour is so penetrating, labs sometimes keep pyridine in a secondary container with a lid, which helps contain the smell as well as spills. Keep the bottle capped, upright and dated, and record each use in the cabinet log.

How to tell it has deteriorated

Smell is the main signal. A bottle of pyridine that can be detected from outside the cabinet is leaking vapour past its cap. Level loss against the log, crust or sticky residue on the neck, and a label stained or softened by drips are the other checks. The liquid may also darken from colourless towards yellow with age, though that depends on how the bottle has been kept. Look for bulging or sucked-in containers. It is flammable and harmful if inhaled, so nobody should open an old bottle to compare colour with a fresh one.

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 We do not publish a drain or general waste route for any chemical.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 flammable laboratory pack with compatible chemicals.

Specialist collection is the only route for pyridine. Record the volume left, the bottle size and whether the cap is sound, and describe it as a highly flammable liquid harmful by all routes. It is never poured into a sink, left to evaporate in a fume cupboard or burnt off. The discarded organic chemical code usually applies when it is collected outside a lab pack. The carrier packs it upright in compatible packaging, apart from hypochlorites, acids and oxidisers, and prepares the paperwork for a hazardous movement, which the producer still signs and keeps.

Waste codes for Pyridine
Usual EWC code, laboratory stock16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
Usually classed as hazardous wasteYes

20 01 13* (solvents) belongs to municipal collections and is shown for reference only. It is not the normal code for a laboratory collection.

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

  • OxidiserOxidisers can ignite flammable materials or make a fire far more intense.
  • AcidSome acids, especially oxidising 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 hypochloriteHypochlorites and chlorine releasing products can react dangerously with this amine, giving toxic chlorinated products.
  • Chloramine THypochlorites and chlorine releasing products can react dangerously with this amine, giving toxic chlorinated products.
  • 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.
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  • Sodium dichloroisocyanurateHypochlorites and chlorine releasing products can react dangerously with this amine, giving toxic chlorinated products.
  • Sodium hypochloriteHypochlorites and chlorine releasing products can react dangerously with this amine, giving toxic chlorinated products.
  • Sulfuric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • 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

Usually held as: neat.

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

  • H225 Highly flammable liquid and vapour.
  • H302 Harmful if swallowed.
  • H312 Harmful in contact with skin.
  • H332 Harmful if inhaled.
Precautionary statements
  • P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P233 Keep container tightly closed.
  • P240 Ground and bond container and receiving equipment.
  • P241 Use explosion-proof electrical, ventilating and lighting equipment.
  • P242 Use non-sparking tools.
  • P243 Take action to prevent static discharges.
  • P261 Avoid breathing 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.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • P301+P317 IF SWALLOWED: Get medical help.
  • P302+P352 IF ON SKIN: Wash with plenty of water.
  • P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
  • P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
  • 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.
  • P370+P378 In case of fire: Use suitable extinguishing media to extinguish.
  • P403+P235 Store in a well-ventilated place. Keep cool.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

How can I tell if a pyridine bottle is leaking?

The smell is the clue: if you can notice it outside the flammables cabinet, vapour is escaping. Also check for level loss, a sticky neck and a stained label, but avoid opening the bottle to investigate.

Can leftover pyridine be left to evaporate in a fume cupboard?

No. Evaporating a highly flammable, harmful liquid is not a disposal route and it releases vapour into the extract system. It goes by specialist collection.

Should it sit near bleach based cleaners?

No. Pyridine is incompatible with hypochlorite products, so keep them in separate cabinets. If they currently share a cupboard or spill tray, arrange for trained staff to correct the storage arrangement.

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 C5H5N. EC number 203-809-9.

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