Excessive use of candles and tea lightsFogging is understood as ghosting black dust deposits, which can partly occur overnight in apartments. The oily, greasy deposits on walls and furniture can only be cleaned with great effort. Diploma chemist Martin Wesselmann from Hamburg sees a gender-specific problem group among those affected. In 62% of the households surveyed by Wesselmann lived women and in 33% couples or families. Only 5% were pure male households. The excessive use of candles and tea lights is the main cause of black dust. The gender-specific allocation of causes is based on 132 dwellings.