Oak processionary posed a health threat. In April 2018, an outbreak of the caterpillars was reported across Greater London and surrounding areas. The moth is now fairly common in Belgium, notably in the Campine but also elsewhere, with fluctuating population numbers from year to year. In 2007 infestations in the Belgian province of Limburg were so acute that soldiers were deployed to burn them. In the Netherlands, the caterpillars are dealt with by biological pest control. Local authorities use, like in Germany, fluids containing bacteria that are toxic only to the caterpillars. These fluids are sprayed onto the infected trees. Furthermore, an
Health Hazard Evaluation Program employees are sick and the cause is unknown or the number of illnesses or injuries is higher than expected in a group of employees. Requests should also be made when employees are exposed to a new hazard or a hazard unregulated by OSHA or when employees are experiencing ill health when their exposure to an agent is below the occupational exposure limits. If multiple hazardous agents or conditions are present in the workplace, an HHE request can be beneficial. Common hazards evaluated include chemicals, particulates, noise, radiation, biological agents, ergonomics, heat stress, and occupational stress. An HHE can be requested