Bathroom extractor fans exhaust the indoor air to the outside via a duct. They are important for several reasons. They remove unpleasant odours and pollutants from your bathroom.
But their most important function is the removal of warm, moist air created by baths and showers. Warm, moist air encourages the growth of unhealthy mould and mildew and can damage fixtures and surfaces.
For a safer, healthier bathroom, install an extraction system in your home.