Safety Alert: Liquid nitrogen asphyxiation incident

Cryogenic liquids such as liquid nitrogen are widely used in various industries such as laboratories or in the case of food industries for its freezing properties. following is a recent incident that highlights the importance of ensuring the correct precautions are in place for your application.

The Gainesville tragedy

On the 28th of January, 2021, a tragic incident occurred at a food processing plant in Gainesville, Georgia, USA, where an overflow of liquid nitrogen from an immersion freezer unit led to a catastrophic outcome. Six workers lost their lives and another four sustained injuries.

The situation unfolded during a routine maintenance check of the freezer, which inadvertently triggered the release of liquid nitrogen. The liquid quickly turned into gas, filling the unventilated space, and resulting in the fatal asphyxiation of the two workers conducting the maintenance.

The hazardous situation remained unnoticed for a period ranging between 30 to 60 minutes. It was only when another employee went searching for the maintenance team that the severity of the situation was realised.

Following this discovery, management was alerted, and an immediate evacuation was ordered. During the evacuation, no less than 14 individuals, including members of the management team, either ventured into the freezer room to assess the situation or endeavoured to aid their colleagues. This act of bravery had dire consequences, leading to the asphyxiation of four more workers. Additionally, three employees and one firefighter received medical attention for symptoms related to asphyxiation.

Recommendations for your application.

The following measures can be applied to your operation to ensure the risk of asphyxiation is mitigated:

PPE: The correct respiratory protective equipment (RPE) provides protection in environments with low levels of oxygen, such as when working in confined spaces or rescue situations. Ensure equipment is tested regularly and staff are trained in its use.

Ventilation: In environments where inert gases are present, whether through storage, processing, or incidental creation, adequate ventilation is essential to mitigate gas exposure risks.

Gas monitoring: Facilities should implement as appropriate fixed and personal gas detection and alarm system tailored to the specific gases in question, ensuring continuous monitoring and alerting of personnel when gas levels become elevated. In the case of nitrogen, an oxygen gas detection system is required to monitor oxygen displacement potential. Individuals who work near these zones are advised to utilise personal gas monitors. These devices are crucial for early detection and warning against the accumulation of dangerous gas concentrations.

Access Management: It’s important to note that attempts to rescue colleagues in environments with toxic gases or insufficient oxygen often result in fatalities. To prevent such tragedies, entry into these areas must be strictly regulated, requiring appropriate permits, readiness, and respiratory protection equipment.

Safety Alarms: Evacuation alarms play a vital role in signalling the occurrence of critical incidents. It is imperative that all personnel, including visitors, are well-informed about the correct procedures to follow in response to these alarms.

For more information regarding safety with gases, contact Coregas at www.coregas.com/contact or www.coregas.co.nz/contact

Image source: https://www.theguardian.com/en...

Image source - Gas detection example: https://www.draeger.com/