Zeta Fresh Air for welding and cutting

Dangerous elements are present in the welding workplace and suitable respiratory protection should be used to protect both short and long-term health. Welding fumes and gases are created through the burning of parent metals, welding filler materials, their coverings, shielding gases, paints, and chemical reactions from the arc’s ultraviolet light and heat process, including contaminants in the air from solvents and cleaners.

Exposure to welding fumes is a serious occupational hazard and can cause many health problems if carried out without respiratory protection. Ultraviolet radiation given off by welding reacts with oxygen and nitrogen in the air to form ozone and nitrogen oxides, which can be life-threatening in high concentrations, cause lung disease, and in small concentrations, irritate the nose and throat.

A single production welder can produce 20-40 g of fumes per hour, which corresponds to about 35-70 kg of welding fumes per year. Occupational exposure limit levels (OEL) to welding fume particulate is defined by mg/m³, i.e., the concentration of fume in the air, measured by its weight in milligrams per cubic meter of air. For general welding fumes, the point at which it is recommended to use respiratory protection is 5 mg/m³. Check your local standards authority and recommendations and ensure the Kemppi respiratory device you select meets your personal needs.

A welding respirator consists of a Powered Air Purifying Respirator (PAPR) unit, air hose, and welding helmet with an integrated face seal. The PAPR has a fan motor that is powered by a battery. It is equipped with a particulate filter or a combination of particulate and gas filters. There are also supplied air delivery systems, which use known breathable pure compressed air.

The purified air is led along with the air hose to the helmet creating positive pressure inside the helmet shell and face seal. Positive pressure inside the welding helmet means that breathing is easy and ambient contaminated air cannot flow inside the helmet. It is a so-called positive pressure respirator.

There are no common rules for which filter should be used with specific materials. It depends on many details such as surface treatment, purity of the material, and contamination of the environment like air (i.e., ozone). A combination filter (particulate and gas filter) always creates the best protection against harmful fumes and gases.

Please refer to our Welding Safety catalogue for a more detailed table about filtering devices and chemicals.

The PFU 210e PAPR has an automatic filter condition measuring system. An LED light in the user interface illuminates red, the vibration motor starts running and an alarm noise can be heard when the filter needs to be changed at once. It is reasonable to follow the LED light color in the user interface. When it illuminates as orange, it is quite close to being clogged and needs to be changed. If the battery runtime starts to be too short, changing the particulate filter or prefilter can help.

The gas filter is not collecting particles in it as the particulate filter does (the gas filter does not clog as the particulate filter does). That is why the particulate filter needs to always be fixed on the gas filter = combination filter. The only way to find out if a gas filter is still filtering gases as it should is the smell test. If a user can feel any smell coming through the welding helmet, the gas filter needs to be changed at once. If the harmful gas does not smell, then a regular gas filter change interval is recommended.

The nominal protection factors assigned by the European Standard Authorities to a class of a respirator (PAPR or Airline supplied device fitted with a hood or a helmet under standard EN12941) define a Nominal Protection Factor (NPF) based on the tested inward leakage efficiency of the respirator device. For TH2 certified welding respirators, the inward leakage is allowed to be max. 2%. For TH3 certified welding respirators, the inward leakage is allowed to be max. 0.2 %. All Kemppi PAPR welding respirator models are following standard EN12941, and their class is either TH2 or TH3.

Supplied Air Respiratory Protection means that breathing air delivered to a fresh air welding helmet is created by a compressor. Supplied air sources must meet mandatory local breathable air quality regulations.

Welder's respirators connected with a breathable air supply from a compressor meeting EN 12021 are defined under EN 14594. The Kemppi welder's respirators must only be used in areas where the oxygen content exceeds 17% and must not be used as a self-contained breathing apparatus, or for escape purposes.

Powered Air Respiratory Protection means that breathing air coming inside the welding helmet is purified by a battery-operated filtering unit (see above “How does a welding respirator work” or compressed breathing air system (see above “What is Supplied Air Respiratory Protection?”). Powered Air Respiratory Protector means the same as Powered Air Purifying Respirator and it is shortened to PAPR.

Disposable welder's face masks are a cheaper solution if only welding occasionally. However, professional welders and fabricators would typically use 1 x disposable mask per day and over time those costs would multiply and outweigh the investment cost of a quality PAPR or supplied air system, including replacement maintenance filters, not to mention the amount of waste that disposable masks cause. Usually, PAPR systems give better breathing protection and are more comfortable in long-term use because of cooling air circulation.