An occupational acne-like eruption due to prolonged contact with certain chlorinated compounds (naphthalenes and diphenyls); keratinous plugs (comedones) form in the pilosebaceous orifices, and variously sized small papules (2 to 4 mm) develop. Synonym: chlorine acne, tar acne. Chloracne is an acne-like eruption of blackheads, cysts, and pustules associated with over-exposure to certain halogenated aromatic compounds, such as chlorinated dioxins and dibenzofurans. The lesions are most frequently found on the cheeks, behind the ears, in the armpits and groin region. The condition was first described in German industrial workers in 1897 by von Bettman, and was initially believed to be caused by exposure to toxic chlorine (hence the name "chloracne"). It was only in the mid-1950s that chloracne was associated with aromatic hydrocarbons. The substances that may cause chloracne are now collectively known as chloracnegens. Chloracne is particularly linked to toxic exposure to dioxins (byproducts of many chemical processes, including the manufacture of herbicides such as Agent Orange) so much so that it is considered a clinical sign of dioxin exposure. The severity and onset of chloracne may follow a typical asymptotic dose-response relationship curve. An OSH glossary used in safety and health at work which is, adopted by ILO