Stunning and slaughter

Decapod crustaceans are often subjected to slaughter methods that cause extreme suffering. In the food industry, they are killed in a number of ways, many of which carry a high risk of pain and distress.

One of the most common questions we’re asked is: What is the most humane way to kill a crab or lobster?

It’s an important question because many methods used today, such as boiling alive, cause prolonged and severe distress. When plunged into boiling water or heated gradually to boiling point, these animals

thrash, struggle, and attempt to escape, clear signs of suffering.

We believe this is unacceptable.

To be humane, slaughter must begin with effective stunning that renders the animal insensible to pain within one second, followed by swift mechanical killing before cooking. These steps require specialist equipment and trained professionals, meaning humane slaughter cannot be carried out at home. Anything less risks causing severe pain and distress.

Humane stunning

Humane slaughter begins with stunning, the process of making the animal completely insensible to pain and distress. This insensibility should happen instantly and be maintained until death occurs, and be followed by a swift and effective killing method.

Electrical stunning

Currently, electrical stunning is the only method shown to achieve this for crabs, lobsters, and other decapod crustaceans. When applied correctly, it renders the animal unconscious within one second, preventing the suffering caused by other practices such as boiling alive, chilling, chemical anaesthetics, or CO₂ gassing.

Electrical stunning is the only method proven to deliver a swift (within one second), effective stun, causing a total loss of central nervous system activity and responsiveness to sensory stimulation. When applied correctly, it prevents suffering, but it must be followed immediately by a rapid and effective killing method.

Electrical stunning alone is not a humane method of slaughter.

How it works

Instant insensibility: The animal becomes completely unconscious and unable to feel pain.
Maintained until death: Stunning is followed by swift mechanical killing before cooking.
Species-specific parameters: Correct electrical settings are essential for crabs, lobsters, crayfish, and shrimp.

Electrical stunning should only ever be carried out using approved, specialist equipment by trained professionals. While we do not endorse any particular device, machines are already available on the market, and research continues to refine the most effective parameters for different species.

Humane slaughter after stunning

Effective stunning, which is guaranteed to last throughout the entire process, must take place prior to slaughter, regardless of the slaughter method used.

Mechanical slaughter (spiking or splitting)

Skilled, competent application of certain methods of mechanical killing of decapod crustaceans that effectively destroy their nerve centres can result in relatively swift (though usually not instantaneous) death.

Such methods include the ‘double spiking’ of crabs or the ‘full-body splitting’ of lobsters and similarly shaped species. These different techniques must be used due to contrasting layout of these species' ganglia. A lobster's ganglia run through the length of the body, so they must be cut fully down the longitudinal midline on the underside to ensure destruction of all ganglia. Spiking of the head alone of lobsters is ineffective and should never be performed. We recommend that mechanical killing is done after electrical stunning.

Due to the skill required to achieve accurate and speedy spiking/splitting, if not done correctly these methods cause severe suffering. Mechanical killing should only be applied by trained, competent practitioners, immediately after the animals have first been effectively electrically stunned, and before they are cooked.

It is essential that all nerve centres are destroyed simultaneously to avoid pain and distress, making mechanical killing (spiking or splitting) incredible difficult to achieve humanely.

Boiling after stunning

The boiling of effectively stunned decapods as a method of slaughter is humane, as long as the stun lasts throughout the entire slaughter process. Please read the below section on inhumane stunning and slaughter to find our more about why live, conscious boiling should never be done.

Inhumane slaughter

Many of the methods still used to prepare crustaceans for consumption are not only ineffective, they cause extreme suffering. The most notorious is boiling animals alive while fully conscious. Others, like chilling, are mistakenly believed to be humane but in reality prolong suffering.

Chilling or freezing

Placing decapod crustaceans like crabs or lobsters in a fridge, freezer, or on ice may make them appear still, but research shows it does not induce unconsciousness or anaesthesia, only paralysis. This means they can still feel pain, they just can't move away from it. Worse, chilling before boiling actually increases the time it takes for them to lose consciousness and die. Decapod crustaceans should never be chilled for the purposes of stunning or killing.

Boiling alive

Boiling is one of the most common slaughter methods but unfortunately also one of the most cruel. When plunged into boiling water, lobsters and crabs thrash violently, try to escape, and even shed limbs, clear signs of stress for crustaceans. It can take up to three agonising minutes for them to lose consciousness. This is an unacceptable length of time to suffer.

Based on current scientific evidence, the following methods are considered inhumane and should not be used on decapod crustaceans:

Live, conscious boiling
Chilling in the fridge, freezer or in an ice slurry
Dismemberment of live animals
Freshwater drowning
Electrical killing
High pressure processing
High salt solution
Carbon dioxide (CO2) gassing
Chemical anaesthetics

To find out more about these methods, head to our policy page.

There are many examples of good practice that is already occurring in the food industry. But with no legal guidelines, there is no obligation for the food industry to treat crabs, lobsters and other decapod crustaceans humanely, either in storage or during slaughter.

This is why we work with food businesses to implement changes to their practices; and we put pressure on the Government to make the necessary changes to the law.

Ban boiling alive

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