[en] A simple rapid method is described for determining the tritium contamination of the air (in the form of HTO) in luminous paint plants. Air is collected in a soft plastic half litre bottle by squeezing the bottle ten times and adding 10 ml water to absorb the HTO into the water phase; the tritium concentration is subsequently determined by liquid scintillation counting. This method of measuring HTO was compared to an alternative method which freezes the atmospheric moisture; good agreement between the two methods was achieved in the range 30 nCim^-3 to 10 μCim^-3. Although the freezing method is nearly three times more sensitive, the bottle method is simpler, faster and adequate for quick checks in laboratories or the environment in determining whether the air concentration of HTO is above or below the legal limit. (UK)