Processionary caterpillars: which workers are most exposed?
The occupations most exposed to the stinging hairs of processionary caterpillars are lumberjacks, silviculturists, forestry operators and workers maintaining or developing green spaces. These are the findings of the CheniPRO workplace study conducted by ANSES in partnership with the Agricultural Mutual Insurance Scheme (MSA). It is essential that workers wear suitable protective equipment to prevent the risks of exposure.
Professionals working with wood and green spaces are at highest risk of exposure
Because they often work in contact with oak or pine trees, woodworking and forestry professionals, workers maintaining or developing green spaces, and equestrian professionals are particularly at risk of exposure to the stinging hairs of processionary caterpillars.
To gain a better understanding of this exposure, ANSES carried out the CheniPRO study in December 2022. An electronic questionnaire was sent to professionals identified by the MSA Central Fund.
Of the 900 respondents, 72% reported that they had been exposed to processionary caterpillars in the course of their work. This exposure concerned 81% of professionals working with wood and 75% working with green spaces, as well as 38% of equestrian professionals.
Woodworking professionals were most likely to have already experienced symptoms, mainly dermal. These primarily concerned exposed areas of the body such as the arms and neck. The appearance of symptoms increased with the frequency of exposure: 83% of workers exposed more than ten times a year reported symptoms, compared with 38% of those exposed less than once a year.
These results were taken into account in the expert appraisal carried out by ANSES to assess the risk of exposure to stinging caterpillars.
Wear protective equipment
To avoid any contact with stinging hairs when working on trees or in infested areas, ANSES reminds professionals that they should wear personal protective equipment that protects the skin, eyes and respiratory tract.
Equipment recommended by the National Research and Safety Institute (INRS):
- Disposable coveralls;
- High-topped shoes;
- Impervious gloves (latex not cloth) with gauntlets, and disposable under-gloves (latex or vinyl) worn under the work gloves, enabling soiled clothing and equipment to be removed without contaminating hands;
- Helmet with cape and powered respirator;
- Or coveralls with hood, safety helmet and full-face mask with powered respirator;
- Or coveralls with hood, and over-hood with powered respirator.
Caterpillars with stinging hairs
Some species of caterpillars found in metropolitan France produce stinging hairs. This is the case of the pine and oak processionary caterpillars, the browntail moth caterpillar and the four-spotted footman caterpillar (Lithosia quadra) in particular.
>> Find out more about processionary caterpillars.