Carbon monoxide levels are low, but not well-monitored

We've updated our factsheet covering concentrations of carbon monoxide and the distribution of monitoring stations around New Zealand.

The Headline: Levels of carbon monoxide (CO) in the few areas monitored in New Zealand are well within the limits of the national air quality standard and meet all WHO guidelines. However, CO remains a hazard in indoor environments, for which no monitoring system exists.

Key Facts:

  • There are 12 outdoor carbon monoxide monitoring stations in New Zealand, located only in two regions: Canterbury (9 stations) and Greater Wellington (3 stations). Only 7 of these monitoring stations had valid data for 2020, the latest year of data.
  • There have been no exceedances of the national standard for CO (8-hour average) since 2006. These exceedances were minor.
  • The last exceedances of the 2021 WHO guideline for daily average CO concentrations were also in 2006.


You can view the factsheet interactive format: Carbon monoxide concentrations | New Zealand | Report Builder for ArcGIS (

...As a PDF: Carbon-monoxide-concentrations