Pre-filters aligned to EN143 can only be fitted to gas vapour filters. This combination can significantly increases breathing resistance. Higher breathing resistance /  high tempo of work may cause the mask to become unseated from the wearers face, reducing the protection offered to the wearer.

Key points:

• Pre-filters (EN143) are only compatible with gas vapour filters.
• Increased breathing resistance / high tempo work work (high pulmonary stress) may unseat the mask from the wearers face, compromising protection. Understand limitations not to be exceeded.