Pharmaceutical Desiccants, the distributors "wonder sensor oxygen indicators" manufactured by 'Powder Tech', detect oxygen over 0.5% by changing its colour to blue. These indicators are put in an environment containing less than 0.1% oxygen; after absorption, the indicator turns pink. Wonder sensors are paper-type indicators which fit in food, pharmaceutical and nutraceutical packaging. Oxygen indicators are small, individually packed indicators that detect the presence of oxygen. The presence and absence can be revealed via colour change. The indicators can also indicate a lack of oxygen up to 0.01% by turning pink in colour, and at the greatest oxygen level of 0.5%, the indicator turns blue. The oxygen indicators are most probably used with food packaging, diagnostics, chemicals and other oxygen-sensitive products.