High Concentrations of Carbon Dioxide in Coolstores
Event Title: High concentrations of Carbon Dioxide within and nearby Kiwifruit Coolstores
Event date: 30th July 2020
Event Description:
Industry workers have reported high levels of Carbon Dioxide (CO2) in and around kiwifruit coolstores. Concentrations recorded have been above New Zealand Workplace Exposure Standards (WES) for both Time Weighted Average (TWA) and Short Term Exposure Limits (STEL).
New Zealand Workplace Exposure Standards for CO2 are as follows:
- TWA = 0.5% (8 hour working day)
- STEL – 3.0% (15 minute)
One event saw CO2 exceeding 3% which is above the NZ WES STEL. This was recorded outside a Modified Atmosphere coolstore. A second event was within a traditional coolstore saw workers record CO2 at 2.67% on their personal gas meters. There have been several other cases of CO2 above the NZ WES TWA as indicated in the below graph.
Previous seasons have suggested a risk of higher CO2 levels during the early part of the season due to kiwifruit that is warmer respiring (producing CO2) more quickly, these recent events indicate the risk remains throughout the season. These incidents reaffirm the importance of the recommendations from an independent Risk Assessment of Carbon Dioxide completed by Air Matters.
Initial Actions Taken:
- In both the above cases, the workers ceased their work activities and reported the situation to site management.
Lessons and Recommendations:
- Coolstore operators should ensure their operations adequately consider the risk of CO2 accumulating in their coolstores and have methods in place to manage this risk.
- Work areas nearby Modified or Controlled Atmospheres should be considered as areas of risk.
- Workers and visitors should have in place a way to ensure the risk of CO2 is being managed through personal gas meters and/or other means of verification prior to entry.
For further information please contact Angus Bell (Angus.bell@zespri.com or 021 819 874)