Reference
Chemical hazards and COSHH starting points
A practical reference for the substances UK research labs keep on the shelf: current GHS classification from PubChem, what the codes mean in plain English, and the questions your COSHH assessment needs to answer for each hazard class.
- Classification sourced from PubChem and attributed
- Hazard and precautionary codes in plain English
- Written for the person actually doing the assessment
This is a reference, not an assessment. These pages summarise published classification data to help you start. The safety data sheet for the grade and supplier you actually hold is the authoritative source, and a COSHH assessment must reflect your task, your quantities and your controls.
Solvents
Acetone
CAS 67-64-1
The default glassware-rinsing solvent — and one of the most common flammable liquids on a lab bench.
Hazards & COSHH promptsMethanol
CAS 67-56-1
An HPLC and cleaning workhorse that is far more acutely toxic than its familiarity suggests.
Hazards & COSHH promptsEthanol
CAS 64-17-5
Used everywhere from surface disinfection to precipitation, and stocked in quantities that add up quickly.
Hazards & COSHH promptsIsopropanol (propan-2-ol)
CAS 67-63-0
The other everyday alcohol — cleaning, precipitation and disinfection, with the same flammability questions as ethanol.
Hazards & COSHH promptsAcetonitrile
CAS 75-05-8
The standard reversed-phase HPLC solvent, bought in bulk and generating volumes of waste to match.
Hazards & COSHH promptsChloroform (trichloromethane)
CAS 67-66-3
Still standard in nucleic acid extraction, and one of the substances most likely to need substitution review.
Hazards & COSHH promptsDichloromethane
CAS 75-09-2
A synthesis and chromatography staple with a carcinogenicity classification and tight exposure limits.
Hazards & COSHH promptsToluene
CAS 108-88-3
A common aromatic solvent carrying both flammability and reproductive-hazard classifications.
Hazards & COSHH promptsHexane
CAS 110-54-3
Highly flammable extraction solvent with a nerve-damage profile on repeated exposure.
Hazards & COSHH promptsDiethyl ether
CAS 60-29-7
Extremely flammable, and forms explosive peroxides in storage — the classic 'old bottle at the back' hazard.
Hazards & COSHH promptsAcids & bases
Acetic acid (glacial)
CAS 64-19-7
Deceptively familiar — glacial strength is corrosive and combustible, unlike the dilute acid most people picture.
Hazards & COSHH promptsHydrochloric acid
CAS 7647-01-0
Standard concentrated mineral acid; the fumes cause as many problems as the liquid.
Hazards & COSHH promptsSulfuric acid
CAS 7664-93-9
Highly corrosive and strongly exothermic on dilution — the heat is the hazard people underestimate.
Hazards & COSHH promptsNitric acid
CAS 7697-37-2
Corrosive and a strong oxidiser — the incompatibility list is what usually causes incidents.
Hazards & COSHH promptsSodium hydroxide
CAS 1310-73-2
The standard strong base; dissolving pellets generates significant heat.
Hazards & COSHH promptsAmmonia solution (ammonium hydroxide)
CAS 1336-21-6
Corrosive base whose vapour pressure makes opening the bottle the riskiest moment.
Hazards & COSHH promptsFixatives & biological reagents
Formaldehyde solution (formalin)
CAS 50-00-0
The standard fixative, and a recognised carcinogen with tight workplace exposure limits.
Hazards & COSHH promptsParaformaldehyde
CAS 30525-89-4
Powder form that depolymerises to formaldehyde — heating to dissolve it is the exposure risk.
Hazards & COSHH promptsPhenol
CAS 108-95-2
Present in many nucleic-acid extraction reagents; causes severe burns that can be painless at first.
Hazards & COSHH prompts2-Mercaptoethanol
CAS 60-24-2
Reducing agent used in protein and RNA work — acutely toxic and unmistakable by smell.
Hazards & COSHH promptsEthidium bromide
CAS 1239-45-8
The classic DNA stain and mutagen — the reason many labs run a designated area and waste stream.
Hazards & COSHH promptsAcrylamide
CAS 79-06-1
Neurotoxin and suspected carcinogen in its unpolymerised form — the powder is the dangerous state.
Hazards & COSHH promptsOxidisers & reactives
Sodium azide
CAS 26628-22-8
Preservative in buffers and reagents that is acutely toxic and forms explosive metal azides in drains.
Hazards & COSHH promptsHydrogen peroxide (30%)
CAS 7722-84-1
Strong oxidiser whose concentrated form behaves nothing like the pharmacy bottle.
Hazards & COSHH promptsPotassium permanganate
CAS 7722-64-7
Strong oxidising solid that reacts vigorously with organic material.
Hazards & COSHH promptsSilver nitrate
CAS 7761-88-8
Corrosive oxidiser used in staining and analysis, with significant aquatic toxicity.
Hazards & COSHH promptsAssessments are easier when the inventory is already there
Build COSHH from your own chemical list.
LevelSixLabs keeps the inventory and the assessments in one place, so a COSHH form pulls the substances, hazards and locations you already hold instead of asking you to retype them.