Indicators 4.2.3.2–4.2.3.5, 4.2.3.8 and 4.2.3.9

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Indicators 4.2.3.2–4.2.3.5, 4.2.3.8 and 4.2.3.9

by Contact on 8 October 2026

Requirement

The UoC shall ensure crustaceans are killed immediately after harvest: a) by immersion in an ice slurry bath; or b) through an electrical device followed by immersion in an ice slurry bath.

The UoC shall not process crustaceans alive.

The UoC shall ensure ice slurry baths are maintained at ≤4°C at all times and crustaceans are immersed for an appropriate amount of time to be killed effectively.

The UoC shall ensure that if electrical devices are used for stunning the manufacturer’s instructions are followed.

The UoC shall ensure that killing has been effective by verifying the absence of coordinated leg and body movements.

The UoC shall have measures in place to immediately respond to ineffective stunning or killing, including the presence of a back-up system, and shall implement appropriate corrective actions to prevent recurrence.

How Do I Interpret This Requirement?

  • Slaughter is generally a two-stage process:

    • The crustacean is first stunned to make it insensible to pain.

    • Killing is then carried out (see interpretation in Indicator 4.2.3.10).

    • An effective stun is determined by the loss of consciousness using an electroencephalogram (EEG) measured in a laboratory, which is not practicable at a site level.

    • Current stunning methods for crustaceans include a controlled ice slurry bath at ≤4 °C or electric stunning followed by an ice bath.

    • To ensure a controlled ice slurry bath at ≤4 °C, the ice slurry bath should be adjusted in relation to the amount and crustacean size. Below is an example for a batch of crustaceans using an ice slurry bath maintained at ≤4 °C.

    • Preparation: determine the approximate amount and size of crustacean by considering the amount planned for slaughter and taking a sample of the pond.

    • Results of amount and size: e.g. 5kg of medium-sized crustaceans (approximately 15cm each).

    • Ice slurry preparation: create an ice slurry bath in a large, insulated container. For 5kg of crustaceans, prepare an ice slurry mixture with approximately 10 Liters of water and a sufficient amount of ice to maintain the temperature at ≤4 °C.

    • Add ice gradually to the water, continuously stirring to create an even slurry.

    • Monitor the temperature using a thermometer, ensuring it reaches and stays at ≤4 °C.

    • Adjust according to crustacean size and amount: since the crustaceans are medium-sized and weigh a total of 5kg, ensure that the ice slurry bath can accommodate the entire batch without overcrowding. Overcrowding can reduce the effectiveness of the ice slurry by raising the temperature.

    • Immersion: gently place the 5kg of crustaceans into the ice slurry bath, ensuring they are fully submerged.

    • Stir the ice-slurry occasionally to maintain uniform temperature distribution.

    • Define the timing for effective Killing: for medium-sized shrimp, a typical immersion time in an ice slurry bath at ≤4 °C is around 2-7 minutes.

Table 14: Suggested time In Ice bath for killing of Penaeus vannamei shrimp

Size of shrimp Time in ice bath

<40 pcs/kg 2 minutes

40- 60 pcs/kg 5 minutes

60-80 pcs/kg 7 minutes

  • Immersion time: set a timer to ensure all shrimp are effectively killed using the timings worked out.

  • Monitoring and verification: periodically check the temperature of the slurry bath to ensure it remains at ≤4°C. Add more ice if necessary to maintain the temperature. Check for indicators of death according to Indicator 4.4.5.

    • In extreme hot conditions, and the impossibility to stabilise the temperature of the slurry bath, a range of temperatures may be accepted.

  • After the set time, remove a few shrimp and check for the absence of movements; the shrimp should also exhibit body rigidity, indicative of effective killing.

Table 15: Determination of the effectiveness of stunning and / or killing based on behaviour

| Shrimp behaviour | Effective stun and / or kill | Ineffective stun and / or kill |

| Movement | Little movement of the shrimp; lying belly up or on side with no attempt to right themselves and under the water surface | Showing active movement, at the surface, continuously jumping reflexes or leg movements or recurring |

| | | |

| | Muscle twitches if isolated | |

| Body shape | Curled | Straight lying belly down, attempting to right themselves |

  • The use of body movement as an indicator for the effectiveness of stunning or killing can be misleading as muscular spasms regularly occur in unconscious or dead shrimp. Studies on crustaceans, including shrimp, indicate that they can exhibit reflex actions and movements even when they are unconscious or brain dead. This is because such movements are often dominated by nerve circuits in the peripheral nervous system rather than the brain. Body movements indicating walking leg movements and coordinated swimming movements are relevant movements to watch out for, and that may indicate consciousness

  • Killing effectiveness in the UoC should be assessed by confirming signs of unconsciousness:

    • Immediate loss of balance.

    • Absence of voluntary movements.

    • Absence of coordinated swimming movements.

    • Limited pleopods and pereipod movements.

    • Laying on side with no activity.

    • The requirement for killing also applies to animals not destined for human consumption, e.g. bycatch, wild species.

  • If there is uncertainty about whether a crustacean is unconscious:

    • When using an electrical stunning, the stunning should be repeated or the harvest shall stop to verify stun parameters before proceeding, e.g. more than 5 crustaceans in 10 seconds requiring backup stun.

    • Or use an alternative backup method, e.g. ice slurry bath or a secondary electric stunner.

      • When using the ice slurry bath method, the temperature of the bath should be checked, and the length of time in the bath extended.

      • Electric stunning should be performed according to the manufacturer’s instructions.

Evidence of Implementation

  • Employees should demonstrate knowledge of the approved slaughter methods and monitoring.

  • Records:

    • Employee training (see Appendix 12).

    • Slaughter monitoring, e.g.:

      • Verification and registration of stunning and killing of 100 individual crustaceans per harvest.

      • Observation of signs of unconsciousness.

      • Records of the use of backup.

      • Records of stunning and killing of crustaceans not destined for human consumption if applicable.

Auditors Should Confirm

  • Monitoring of stunning and slaughter in conformance to the requirements.

  • Records, employee interviews and observations of stunning and slaughter operations during the audit should demonstrate the implementation of the requirements, and that there is an available backup method or knowledge of corrective measures to be carried out.

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