Business · 4 min read · Updated 6 November 2026

Dental laboratory waste: gypsum, resins, metals and impressions

How lab waste differs from practice waste

A dental laboratory rarely produces much infectious waste, but it handles far more materials than a surgery. Gypsum, resins, metals and investment materials are used in bulk, and several of them become hazardous or problematic once they are waste. Labs are also workplaces with their own dust and chemical risks, so waste management and COSHH go hand in hand. A lab attached to a practice should be included in the practice waste policy, while a standalone commercial lab needs its own waste contract, policy and records.

The main lab waste streams

Why gypsum needs its own container

Gypsum is non-hazardous when dry, but if it ends up in landfill mixed with biodegradable waste, wet and low-oxygen conditions allow bacteria to break it down and produce hydrogen sulphide gas. For that reason gypsum must not be mixed with general waste going to ordinary landfill. Labs produce gypsum in large volumes, so a dedicated, sturdy gypsum container, collected regularly, is usually the biggest single change a lab can make.

Models that are part of a patient's records or ongoing treatment may need to be kept for a period before disposal, so agree a retention period with the practices you work with. When old models are cleared out, remove or obscure patient names and identifiers on labels and bags, as these are personal data. Clearing a backlog of old models is often a one-off collection in its own right.

• Keep gypsum dry where possible
• Remove metal parts and other materials before disposal
• Do not put plaster slurry down the drain, as it sets in pipes; use a plaster trap on sinks
• Use containers strong enough for the weight, as gypsum is heavy

Impressions and items from surgeries

Impressions, bite registrations and appliances arriving from practices can carry saliva and blood. Practices should rinse and disinfect them before sending, and labs should still treat incoming work as potentially contaminated until it has been disinfected on receipt. Agree a disinfection procedure with the practices you work with and keep a record of it. Once disinfected, impression materials can usually go in the non-infectious stream your contractor recommends.

Chemicals, dust and COSHH

• Store acrylic monomer away from heat and ignition sources, and collect waste monomer as flammable hazardous waste
• Never pour monomer, acids or solvents down the sink
• Use local exhaust ventilation for grinding, polishing and sandblasting
• Bag dust from extraction units carefully to avoid releasing it
• Keep safety data sheets and COSHH assessments for every product

Some dental materials contain respirable silica, cobalt, chromium, nickel or beryllium, which can harm the lungs or cause sensitisation. The safe handling of dust during use carries through to how waste dust is bagged and stored.

Metal scrap: waste or value?

Scrap from precious metal alloys, including grindings and sweepings, can have real value and is often sent to a refiner rather than treated as waste. Keep precious and non-precious scrap separate, store it securely, and get records from the refiner. Non-precious alloy scrap can usually go for metal recycling. Extraction filters and bench sweepings in labs that work with precious alloys can also contain recoverable metal, so ask your refiner before throwing them away.

Paperwork for labs

Labs need the same Duty of Care paperwork as practices: waste transfer notes for non-hazardous waste, kept for at least two years, and hazardous waste consignment notes for streams such as monomer and acids, kept for at least three years in England and Wales. In Wales, premises producing or storing more than 500kg of hazardous waste a year must also register as a hazardous waste producer with Natural Resources Wales.

Frequently asked questions

dental laboratory gypsum acrylic dental technicians