In this section
Requesting formalin pots
Requests for Formalin pots will be dealt with as soon as is practicable, however if you require the pots urgently please inform the laboratory by telephone on 12240. Sufficient notice should be given.
Handling formalin
The department uses 10% neutral buffered Formalin (4% formaldehyde) and this should be handled with care at all times. We obtain our formalin from CellSolv, a reputable supplier and they have issued the following safety information:
10% Formalin
Acute Toxicity Category 4 – Harmful if inhaled
Skin Sensitizer Category 1 – May cause an allergic reaction
Carcinogen Category – 1B May cause cancer
Mutagen Category 2 – Suspected of causing genetic defects
All solutions containing formalin are suspected carcinogens, mutagens and sensitisers. The solutions should be handled with care, minimising skin contact. Safety equipment including gloves should be worn and any spill on the skin should be washed as soon as possible. Contaminated clothing should be removed immediately and washed before re-use as the chemical can soak through clothing to stay in contact with the skin for a long period of time. Handle with care and avoid any situations which could potentially result in formalin spillage.
Formaldehyde vapours in the air are also harmful. The safety limit for formaldehyde in air is 2 part per million (2ppm). This means workers should not be exposed to formaldehyde vapour above this level (averaged over the period) for more than 15 minutes at a time. Testing machines are available to monitor the level of formaldehyde vapour in air but as a rough guide, 2ppm of formaldehyde will have a strong, unpleasant smell and will start to sting the nose and eyes on first entering the room. This check is only valid on first entering the room as the senses quickly acclimatise and will be less sensitive. In most hospitals with proper bench extraction it is unlikely that the limit will be reached in normal use but may be in the event of a spill.
Information from: Formalin Usage Guide for Hospitals – CellSolv Version 2 (Jan 2019) (external safety data sheet, contact laboratory if required)
Formalin may be disposed of down a sink suitable for clinical waste with copious amounts of running water in a well-ventilated room depending on local environmental rules. However, please check your local rules.
Formalin spillages
Formalin should be handled with care and sent in appropriately sized containers with secure lids to minimise the risk of a spillage. Specimen pots should be secured in a sealable plastic specimen bag.
Each sender who handles formalin should have their own policy or procedure and equipment for handling formalin and dealing with a spill, and should have sourced from a reputable supplier. Spillages should be dealt with as soon as it safe to do so. Salvage of any specimen should be of the highest importance as it is likely to not be repeatable. Specimens must not be discarded.
The sender must inform the laboratory of any spillage where the specimen may have been lost, partially lost or its integrity compromised. This should be reported as an incident and the sending clinician should be informed as soon as possible.
Couriers and porters should not attempt to handle a formalin spillage in transit without having received proper training. In the event of a spillage please follow local spillage protocols. The Histology laboratory can be contacted for advice Mon-Fri 09:00-17:30 on 0161 701 2240.
Our formalin supplier, CellSolv, has issued the following guidance on spillages.
Spillage volumes:
- Minor spillages (up to 200ml) – usually can be dealt with by 1 or 2 staff using simple procedures
- Large spillages (200ml – 5 litres) – require the use of a formaldehyde spillage kit
- Major Spillages (over 5 litres) – should be dealt with by Fire Service
Dealing with minor spills
In a hospital environment formalin is mostly handled in very small containers with less than 100ml of 10% formalin solution. A spill of this size is unlikely to contaminate the air to dangerous levels if dealt with promptly. The spill can be wiped up with absorbent material by staff members wearing suitable impervious gloves such as nitrile gloves. The contaminated material should be sealed in plastic bags for disposal and removed from the room as soon as possible. It is important not to simply dispose of the contaminated material in an open bin as the formaldehyde will continue to contaminate the air.
Dealing with large spills
Some hospitals use formalin solutions in larger quantities, for example large specimen containers/buckets for whole organ fixing. A spill in this case can be up to ten litres and can cause more serious air contamination. Such a spill should only be tackled by trained personnel with appropriate personal protective equipment. This should include protective gloves, over-suit, boots and respiratory protective equipment (R.P.E.) with forced air feed or formaldehyde selective filters. The spill should be contained by absorbent booms and prevented from entering drains. The spill should then be absorbed into an appropriate absorbent medium, sealed in an airtight container and kept as special waste for professional disposal.
- Evacuate all staff from immediate area and nearby areas of spillage
- Wearing the appropriate personal protective equipment and full face mask, use a formaldehyde spill kit to contain the spillage
- Ensure all materials used to tackle the spillage are appropriately contained and disposed of
Dealing with major spills
- Evacuate the area
- Break nearest fire alarm point
- Phone emergency number for your department (e.g. 2222)
- Inform of nature and site of spillage
Dealing with Biological spills
- Please contact Paediatric Histology on 0161 701 2240 for advice.
(Last reviewed January 2024)