Since the Health and Safety Executive enforcement regarding welding fume published in early 2019, air fed systems for welding and grinding have been in high demand. Air fed or powered air purified respirators (PAPR) supply clean air to the welder by means of a filtration system.

HSE Requirements for Welding Fume Summary

Very basically, the latest HSE expectations is that any business doing any amount of welding should have fume protection measures in place. The prescribed measures by HSE are localised exhaust ventilation (LEV) for indoor welding and respiratory protective equipment (RPE) for residual fume. Outdoors, operators are able to use RPE alone where LEV is not practical. RPE can be worn as a face fit mask or an air fed helmet (PAPR).

Filter Classifications

Businesses all over the UK are having to spend out for equipment to protect their staff from welding fume. Quite rightly then, HSE departments and employers are keen to buy once and buy right to make sure that the equipment purchased is adequate and acceptable by the HSE. We have supplied information to many seeking filtration specifications of the Weltek units and as such thought we should make the information freely available:

This brings us to the main focus of the article, filter classifications. Are Weltek air fed system P3 or FFP3 classified?

Information detailing the filtration levels and classifications associated with the Weltek helmet when used with the Airkos blower unit:

Weltek systems have an APF (Assigned Protection Factor) of 20 Points which comply with P3 classification.

Inward Leakage
TH relates to the inward leakage protection level of a complete system.
TH1: < 10%
TH2: < 2%
TH3: < 0.2%
Airkos systems are classified as TH2

Airkos airfed systems ensures PRSL filtration: Solid & Liquid Particules
R standing for re-usable filter (not to be mandatory disposed of/replaced after every working shift)

Assigned Protection factor
With the combination of TH2 inward leakage and PRSL filtration, the Airkos airfed systems guarantee an Assigned Protection Factor of 20 points.
Identical to a P3 under EN 140, and FFP3 under EN 149
Please see enclosed summary of protection factors on all respiratory protection, including airfed helmets under EN 12941

Weltek Airkos filter classification factors

The above filtration level information has been supplied by Weltek.

HSE information above supplied as a guide. For the latest HSE updates, please visit

Full range of Weltek filters and complete air fed systems available here at TBWS.