RIVM has reviewed the criteria of the Stookwijzer. Based on these new insights, RIVM recommends that households do not light wood fires in winds of 2 or less on the Beaufort scale. In such circumstances, the Stookwijzer will issue a code red. Over 5000 reports have shown that any nuisance as a result of wood burning is strongly linked to wind speed. RIVM also recommends that the Stookwijzer’s recommendations should remain in force for 6-hour time slots, which means that households will have clear idea of what to expect at an early stage and make it easier for them to follow the advice. The Ministry of Infrastructure and Water Management will decide on the implementation of these new criteria.
New insights to substantiate Stookwijzer criteria
The Stookwijzer tool has been advising Dutch households since 2017 on when not to light wood fires, the underlying notion being that wood smoke may always result in nuisance (code yellow). However, in the case of very little wind or already poor air quality, wood smoke has such an adverse impact that it is better not to light wood fires at all (code red).
RIVM has been managing the Stookwijzer since 2023 (atlasleefomgeving.nl/stookwijzer).
RIVM reviewed the criteria for the Stookwijzer at the request of the Ministry of Infrastructure and Water Management, on which basis RIVM recommends that the criteria should be revised. Provided that people observe the guidance not to light wood fires when a code red is in force, the new criteria will have the potential to reduce wood smoke nuisance.
Code red for wind force of 2 or less on the Beaufort scale
RIVM analysed information from over 5000 reports of nuisance due to wood smoke submitted between 2020 and 2022. It has been shown that the number of nuisance reports is closely related to wind speed: the lower the wind speed, the higher the number of reports. Lower wind speeds mean wood smoke is not diluted as effectively, leading to greater nuisance to others. This study shows that more than half of reports are submitted at a wind force of 2 Beaufort or less.
Particulate matter concentrations (PM2.5)
At wind force greater than 2 Beaufort, RIVM also recommends taking into account particulate matter concentrations of 2.5 micrometers (PM2.5) that are already in the air. Wood smoke also contains a great deal of particulate matter (PM2.5). Basing the air quality criteria in the Stookwijzer on this aspect highlights the relationship between lighting wood fires and air quality.
Longer-term advice provides wood-burning households with more clarity
Finally, RIVM recommends issuing advice on lighting wood fires for 6-hour time slots, rather than on an hourly basis. Issuing the advice before the start of the next six-hour period will inform people in a timely fashion of what they can expect.
Stookwijzer and ‘stookalert’ – key differences
The Stookwijzer provides an up-to-date picture of the situation for each post code. Anyone can consult the Stookwijzer at any time of day. A ‘stookalert’ is an active warning not to light wood fires during extremely unfavourable weather conditions in a large area or during smog episodes.