PestWest Quantum BL tubes are designed keeping the environment in mind. These tubes contain considerably less lead and mercury compared with most other fluorescent tubes. They are fully compliant with the European Union\'s new Restriction of Hazarduous Susbstances Directive (RoHS). Most tubes used in fly control units are replaced at the beginning of the insect season but in order to preserve an acceptable level of protection, some UV tubes may well need to be changed more than once a year, particularly where: Species’ populations peak late in the season Traps may be under specified Traps are poorly sited Ambient UV light reduces effectiveness The risk of contamination by flying insects continues into autumn (or beyond) Insect control is critical, e.g. food processing, pharmaceutical plants, hospitals, etc