Inherent hazards and limited regulatory oversight in the waste plastic recycling sector – repeat explosion at pyrolysis plant

Denmark has set ambitious targets for the recycling of plastic and local authorities have rolled out mandatory programs for collection of the waste plastic fraction at households. The waste streams are often dirty and contain many different types of plastic. In comparison to mechanical recycling, the pyrolysis process can tolerate considerably higher levels of contaminants in the feed. Municipalities pay a fee to have recyclers accept the waste and cover transportation costs. This represents a business opportunity for entrepreneurs who devise proprietary pyrolysis processes. Pyrolysis is an inherently hazardous process but barriers to entry appear rather low and regulatory oversight limited. A proprietary pyrolysis prototype plant experienced a serious explosion in 2020. An explosion in 2021 at the same plant led to its complete destruction. The paper examines the limited evidence available and presents a plausible set of lessons not learned. In Denmark, it is a policy objective to encourage circular economy and recycling of waste streams to reduce dependence on fossil fuels. However, utmost care should be taken to avoid media shifting – that the resolution of a problem within one domain, the environmental domain, comes at the expense of problems in another, the workplace safety domain.