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 Health Hazard Evaluation Program The Health Hazard Evaluation (HHE) program is a workplace health program administered by the National Institute for Occupational Safety and Health (NIOSH). NIOSH developed the HHE program to comply with a mandate in the Occupational Safety and Health Act of 1970 to investigate workplace health hazards reported by employers and employees. According to Section 20(a)(6) of the Act, the Secretary of Health and Human Services is authorized "following a written request by any employer or authorized representative of employees, to determine whether any substance normally found in the place of employment has potentially toxic effects in