White meat slaughterhouses: unloading, handling and holding, restraining, stunning, killing

Rules of shackle line operations, waterbath and gas stunners, and facilities for slaughtering poultry, rabbits and hares in abattoirs.

You must hold a certificate of competence (CoC) for each procedure you carry out when working in a slaughterhouse, including handling, restraining, stunning or killing animals.

You must follow the manufacturer’s instructions for any equipment that you use and maintain, and keep a record of any maintenance work for at least a year.

If you’re responsible for stunning, shackling and bleeding animals, you must finish all these tasks on one animal before moving onto the next.

You risk losing your CoC or prosecution if you don’t follow these and other Welfare of Animals at the Time of Killing requirements.

The Mandatory Use of Closed Circuit Television in Slaughterhouses (England) Regulations 2018 require slaughterhouse operators to install and operate a CCTV system that can cover the areas where live animals are present. These include unloading, lairage, handling, restraint, stunning and killing areas. The CCTV system must retain recorded images and information for 90 days and the slaughterhouse operator must provide access to the CCTV system and recordings to inspectors if requested.

Guidance for slaughterhouse operators on compliance tells you how to comply with the rules of this legislation.

Unload animals

You must unload and slaughter animals as soon as possible.

Assess animals on arrival

When animals arrive, your animal welfare officer (AWO), or someone who reports to them, must assess the welfare of each animal in each consignment.

Your AWO must identify:

  • animals you need to slaughter first (prioritise)
  • any welfare needs
  • any measures to take, for example if animals have been subjected to hot or humid weather, you must cool them down
  • keep a record of action taken to improve welfare

Animals in containers

You must treat with care animals delivered in crates or other containers, especially those with a flexible or slatted base. You must keep the containers level. Containers must not be:

  • thrown
  • dropped
  • knocked over

You must have suitable equipment and facilities to unload animals safely from the transport vehicle, such as a forklift truck for unloading containers.

Prioritise animals for slaughter

You must kill an animal as soon as possible if it has an injury or a disease that causes it severe pain or distress.

Sick or injured animals

You must separate animals that are sick or injured and keep them apart from other animals.

Holding areas (lairage)

If you don’t kill animals immediately, you must keep them in a holding area (lairage) with ventilation so they aren’t too hot or cold.

If you can’t slaughter animals straight away, you must:

  • provide drinking water
  • feed them if not slaughtered within 12 hours of arrival and after that at regular intervals

You must inspect each animal regularly and at least every morning and evening.

You must provide enough space to house all animals that need lairaging. If you stack containers:

  • they must be stable
  • urine and faeces must not fall on the animals below
  • ventilation isn’t blocked

Safety and shelter

Lairages must:

  • keep animals safe from potential injuries
  • provide animals with shelter or shade from extreme weather
  • not expose animals to sudden noises
  • keep animals secure so they don’t escape or get harmed by predators
  • be constructed so animals can be easily inspected


Your lairage must be lit well enough for inspections to be carried out. You can have fixed or portable lights.

Drinking water

You must provide access to clean water. You must position drinking containers so that:

  • animals can reach them easily
  • animals can’t foul them
  • you can refill them easily

Where practical, you must fix containers in position.

You must provide enough drinking containers for the number of animals.


You must position any feeding equipment so that:

  • animals can reach food easily
  • animals can’t foul them
  • you can refill them easily

Where practical, you must fix containers in position.

You must provide enough feeding equipment for the number of animals.


You must have natural or mechanical ventilation to protect animals from:

  • extreme temperatures
  • harmful levels of humidity
  • harmful levels of ammonia

Your AWO or company veterinary adviser may offer guidance on the best levels for the species you handle.

If you’ve installed a ventilation system, it must respond to changing temperatures through the year. You must have an alarm and back-up system to cope with breakdowns of mechanical ventilation.

Animal handling rules

You must not handle any animal in a way that causes it pain or suffering. You must not:

  • strike or kick an animal
  • press sensitive areas of an animal’s body that would cause pain or suffering
  • twist, crush or break an animal’s tail
  • grasp an animal’s eyes
  • prods or other implements with pointed ends
  • drag an animal by the head, ears, tail or handle them in a way that would cause pain or suffering

Moving animals to the place of killing

You must only move animals to the place of killing when you’re ready to stun them, and kill them straight away.

You must locate the place of killing so that it avoids unnecessary handling of animals up until the point of killing.

Restraining poultry, rabbits and hares

You need to restrain animals before you stun and kill them.

Your equipment for restraining animals must:

  • allow you to stun or kill an animal effectively
  • prevent injury or cuts to animals
  • minimise struggling and vocalisation
  • minimise the time an animal’s restrained

If you’re using stunning equipment on an animal’s head, your restraining equipment must present an animal’s head correctly for an accurate stun.

You can only use restraining equipment to restrain animals by following the manufacturers’ instructions.

Shackle lines for poultry

Shackle lines must be designed for the size, type and weight of the poultry you’re handling in your slaughterhouse. You must not shackle animals if they’re too small for the shackles or if shackling is likely to cause pain or injury

The shackles must be the right size and shape for the legs of the birds so that electrical contact can be made without hurting the birds.

The shackles must be wet. You must shackle both legs.

Position of shackle lines

You must position shackle lines so that:

  • you can reach the whole shackle line easily and you can take an animal off it at any time, right up to the scald tank
  • you can easily reach the equipment controls at any time
  • the shackles are in continuous contact with the earthed rubbing bar, when they pass over the waterbath

When the birds are on the shackle line they must

  • not touch any objects or each other, even when their wings are stretched out
  • be relaxed
  • not be disturbed

Shackle lines: breast support

If you have new shackle line it must have a support in contact with the breast of the bird to stop it swinging and calm it down. The support must start at the point where the birds are shackled and must extend to the waterbath.

Speed of shackle line

The shackle line must move slowly enough to make sure:

  • you don’t distress the birds
  • the automatic cutters work correctly as the birds pass through

Maximum hanging time

You must only hang conscious birds on a shackle line for a maximum of:

  • 2 minutes - ducks, geese and turkeys
  • 1 minute - other poultry

If you were using a shackle line before 1 January 2013, you can hang the birds for a maximum of:

  • 3 minutes - turkeys
  • 2 minutes - other poultry

From 8 December 2019 the maximum hanging times are the same for all businesses:

  • ducks, geese and turkeys - 2 minutes
  • chickens and other poultry - 1 minute

Stunning animals

You must stun all animals before you kill them, unless you’re carrying out religious slaughter.

Simple stunning

Simple stunning is where you stun an animal to make it unconscious but don’t kill it. It must make the animal unconscious immediately and it must stay unconscious until it’s dead. You must then immediately use another method to kill the animal.

Stunning methods include:

  • percussive blow to the head (rabbits only)
  • neck dislocation (poultry only - use as a back-up method only)
  • non-penetrative captive bolt (avoiding skull fracture)
  • captive bolt
  • firearms
  • electrical stunning
  • waterbath stunning (poultry only)
  • gas stunning (poultry only)

Equipment for stunning or killing

Any equipment you use for stunning or killing must:

  • stun or kill rapidly and effectively
  • be in good working order
  • have the manufacturer’s instructions on how to operate it

You must have back-up stunning equipment available immediately in case your main equipment fails.

Maintain your equipment

You must maintain equipment following the manufacturer’s instructions.

You must keep maintenance records for at least a year. The Food Standards Agency can ask to see them.

Stunning: equipment and monitoring

You must monitor each slaughter line to check animals are being effectively stunned. Between stunning and killing, you must check animals for signs of consciousness.

You must have a CoC on checking effectiveness of stunning. Your slaughterhouse’s standard operating procedure should also list what monitoring procedures will be used

Review your sampling rate

The frequency of your checks that stunning is effective will depend on the main risk factors such as:

  • how often you change the species or size and weight of animals on a slaughter line
  • the length of each shift
  • the results of previous sampling - you’ll need to increase the sampling rate if a previous check found a high percentage of animals were not effectively stunned

If you find an animal that hasn’t been properly stunned, you must take immediate action in line with your slaughterhouse’s standard operating procedure.

If you’re failing to stun animals properly, you must find out what’s wrong and correct your operation immediately.

What to record

You must check a representative sample of the animals you’re stunning. For each sample, you must record:

  • the number of animals
  • the name of the person monitoring
  • the time and circumstances (for example, immediately after stunning an animal)
  • any factors affecting the efficiency of the stunning process
  • whether your findings are consistent with previous monitoring
  • tests of unconsciousness and how to interpret the results
  • religious slaughter - tests for signs of life and how to interpret the results

Waterbath stunning for poultry

You must install a waterbath that’s a good size and depth for the birds that your slaughterhouse processes. You must be able to adjust the water level for different birds so that there is a good contact with each bird’s head. All species of bird must be in the water up to the base of their wings.

Entrance to waterbath

Waterbaths must have an electrically insulated entry ramp so poultry don’t get an electric shock before they enter the waterbath.

You must make sure the waterbath doesn’t overflow at the entrance to prevent pre-stun shocks.

Current and duration

To make birds unconscious immediately and to keep them unconscious until they’re dead, you must make sure:

  • the voltage produces a strong enough current
  • you expose the birds for at least 4 seconds

You must make sure the current and duration are sufficient to stun all the birds. If any birds aren’t stunned effectively you must immediately stun and kill them.

Electrical waterbath stunning: minimum average current and frequency per bird

Frequency (Hz) Chickens Turkeys Ducks and geese Quail
200 Hz 100 milliamps (mA) 250mA 130mA 45mA
From 200 to 400Hz 150mA 400mA illegal illegal
From 400 to 1,500Hz 200mA 400mA illegal illegal

Record the voltage and current

Your stunning equipment must display and record the voltage and current. You must be able to see the display clearly, and you must be able to see and hear a warning easily. These rules apply to equipment that is new after 1 January 2013 and all equipment from 8 December 2019.

You must keep the records for each piece of equipment for a year.


You must be able to get to the waterbath to kill any animals that have been stunned but stay in the waterbath because of a breakdown or a delay in the line.

Gas stunners

You can’t use high concentrations of carbon dioxide on ducks and geese

You can only use gas stunners by following the manufacturers’ instructions.

Gas stunners and their conveyors must:

  • expose birds to the gas long enough to kill them
  • be designed, constructed and maintained to avoid any injury to the bird

Monitor gas concentration

Gas stunners must be able to maintain the correct concentration of gas - they must have a monitoring device that constantly measures and displays the gas concentration. Equipment that is new after 1 January 2013 and all equipment from 8 December 2019 must also record the gas concentration.

The monitoring device must show a warning and sound an alarm if gas concentration falls below the legal level. You must be able to see the monitoring device easily.

You must be able to see and monitor the poultry in the gas stunner. You must be able to:

  • quickly flush the gas stunner with air to enter the chamber
  • get to the poultry in the shortest amount of time

No animals can be in the gas stunner if:

  • there’s a problem with the equipment
  • the gas concentration falls below the required concentration
  • the alarm sounds or the warning lights display

Shackling after gas stunning

Gas stunning must kill the birds. After gas stunning, you must wait until the birds are dead and check they’re dead in line with your standard operating procedures before you can shackle them..

Back-up equipment

You must have back-up equipment you can use immediately available if your main equipment fails.

Gas mixtures

You must use one of the following gas mixtures to kill poultry by gas:

  • carbon dioxide at high concentration (you must not use this method on ducks and geese)
  • carbon dioxide in 2 phases
  • carbon dioxide mixed with inert gases
  • inert gases

You must not allow gases to enter into the chamber (or the location where animals are to be stunned and killed) in a way that could create burns or excitement. This could be caused by the gases by freezing or lack of humidity.

Carbon dioxide at high concentration

The minimum concentration is 40% carbon dioxide. Exposure of a conscious animal to the gas must lead to anoxia (loss of oxygen to the brain).

You must make sure that no animal enters the gas stunner if the carbon dioxide concentration by volume falls below 40%.

You must not use this method on ducks and geese.

Carbon dioxide in 2 phases

Expose the animal to gas with a maximum concentration of 40% carbon dioxide. When the animal is unconscious, use a higher concentration of carbon dioxide.

Carbon dioxide mixed with inert gases

Expose conscious animals directly or progressively to a gas mixture containing up to 30% of carbon dioxide mixed with inert gases. This will lead to anoxia.

You’re breaking the law if you put birds in the chamber when gas concentrations are over:

  • 30% carbon dioxide
  • 2% oxygen (however, the oxygen concentration can rise up to 5% for no more than 30 seconds)

Inert gases

Expose conscious animals directly or progressively to a gas mixture containing an inert gas mixture (such as argon or nitrogen) leading to anoxia.

You must make sure that the oxygen concentration by volume is less than 2% (however, the oxygen concentration can rise up to 5% for no more than 30 seconds).

Head-only electrical stunning

If you’re using electrodes that span an animal’s brain, you must use these minimum currents:

  • chickens - 240mA
  • turkeys - 400mA

The electrodes must be in good contact with the animal and the strength and duration of the current must make the animal unconscious.

The stunning equipment must have a visible or audible device indicating length of time of its application to the animal. It should also clearly indicate to the operator the voltage and current under load.

Low Atmospheric Pressure Stunning

You can use Low Atmospheric Pressure Stunning (LAPS) according to European legislation EU 2018/723 for:

  • slaughter of meat chickens up to 4kg in weight
  • depopulation of meat chickens up to 4kg in weight

This involves exposure of conscious animals to gradual decompression with oxygen level reducing to less than 5%.

Captive bolt stunning

You must use devices, including cartridge strength, in line with the manufacturer’s instructions.

Penetrative captive bolt

You can use penetrative captive bolt devices for simple stunning for all species.

You must:

  • position the device so the bolt enters through the cerebral cortex (top of the brain)
  • check the bolt has retracted to its full extent after each shot

If the bolt hasn’t fully retracted, you must not use the device until it’s repaired.

Non-penetrative captive bolt

You can use non-penetrative captive bolt devices for simple stunning and ensure they’re used in the correct position to avoid the fracture of the skull.

Bleeding poultry

When you bleed poultry after stunning, you must cut the two neck (carotid) arteries properly and without delay. You must make sure each animal bleeds out quickly, completely and dies as soon as possible, without regaining consciousness.

If you kill poultry by bleeding following stunning, you must leave birds to fully bleed out for at least:

  • 2 minutes - turkeys and geese
  • 90 seconds - other birds

You must check for signs of life once bleeding has ended before you dress birds or use any electrical equipment on poultry. You’ll find a list of indicators for signs of life in your slaughterhouse’s standard operating procedures.

Automatic neck cutters

If you’re using automatic neck cutters, they must cut both neck arteries. If they don’t, you must kill the bird straight away using another method.

Emergency killing for poultry

You can use the following to kill poultry as a back-up method to other forms of stunning:

  • manual cervical (neck) dislocation, for birds under 3kg, up to a maximum of 70 birds a day per person
  • mechanical cervical dislocation for birds up to 5kg

Bleeding rabbits and hares

You must bleed rabbits following stunning. You must cut both arteries in the neck. You must make sure bleeding is quick and complete.

Stunning using a percussive blow to the head

This is a simple stun method that can only be used on rabbits that weigh under 5 kg. You must give a firm and accurate blow to the head that leads to unconsciousness.

Published 15 October 2015
Last updated 22 March 2019 + show all updates
  1. Paragraphs about Low Atmospheric Pressure Stunning and Mandatory CCTV coverage added

  2. A paragraph added about the Mandatory Use of CCTV regulations 2018

  3. First published.