Pellet storage: a safety loophole is closed

Transformation  from tree to wood pellets © Antonio Gravante -

The German version of EN ISO 20023, Solid biofuels – Safety of solid biofuel pellets – Safe handling and storage of wood pellets in residential and other small-scale applications, was published in April 2019.

The standard describes requirements concern­ing the entire supply chain, from loading of transport vehicles to delivery at the end user’s pellet store. It adopts numerous requirements of VDI Standard 3464, Storage of wood pellets at the point of end use, which was developed in 2015 under the control of DEPI, the German Pellet Institute, with the support of KAN.

Between 2002 and 2011, several fatal accidents occurred in Europe as a result of CO poisoning. Against this background, EN ISO 20023 describes explicit requirements for the safe design of pellet stores. Adequate ventilation of the store is partic­ularly important here. The standard makes provision for the store builder to confirm compliance with the essential safety require­ments by means of an acceptance report following the store’s initial construction. The standard also addresses safe access to stores (CO measurements etc.) and thus also considers the needs of end users, who often lack detailed expertise in this area.

In Germany, the standard must be applied in conjunction with the Firing Installations Ordinances of the regional authorities, some of which are still being revised.

EN ISO 20023 constitutes part of a larg­er series of standards which also includes standards governing large pellet stores of over 100 tons in capacity. Requirements concerning the technical safety of heating boilers up to 500 kW were recently set out anew in EN 303-5. In 2017, the DGUV also published the Expert committee informative document on carbon monoxide arising during transport and storage of wood pellets for commercial use.