KEMPER

•  During welding, cutting and allied processes such as thermal spraying or soldering, fumes, gases and particles are released. These emissions are classified as hazardous substances.
• These particles can be inhaled, in most cases they may even reach the alveoli and, depending on the chemical composition, can cause severe respiratory diseases and even cancer.
• The emissions also contain a very high number of nanoparticles that can penetrate into human cells and there they may have an as yet unresearched toxicological effect.
• Primarily for reasons of occupational safety, but also for those of environmental protection, measures for air pollution control are required. In this case, the extraction of the emissions at the source represents the best possible protection.

•  End-user’s obligation to take protective measures, to check them regularly and document them. No work to be started without protection measures.

•  Complete capture at source, air recirculation only after adequate cleaning.
• Extraction and filter systems must include state of the art technology and are to be checked at least annually for correct functioning and effectiveness. 

 Selection

1. of processes and filler metals low in hazardous substances- substitution
2. Ventilation measures - capturing emissions
3. Organizational and hygiene measures - avoiding contact, inhalation
4. Personal protection - wearing breathing protection

There are different possible ways of capturing harmful emissions.

1. Source extraction integrated into the welding torch 

• Integration into the system
• Low air flow
• Good to very good capture rate

2. High vacuum - source extraction system

• Efficient source extraction through suction nozzles
• Good capture rate up to a distance of 150 mm
• Simple connection to the extraction system by hoses

3. Low vacuum - Source extraction system

• Easy to use with flexible extraction arms with ease of movement  
• Freely positionable hoods 
• High capture rate at up to 400 mm away

4. Exhaust hood

• Adjustment of the exhaust hood to the respective work area
• Capture of the entire thermal flow from the weld area 
• Very low negative pressure required

5. General ventilation systems

• Two methods: Displacement ventilation (layered ventilation) or mixed air ventilation
• Extraction is carried out at a height of 4-6 m
• To complement the methods already mentioned or if other methods cannot be used

 The effectiveness of the protective measures taken is to be checked, if necessary to be rectified and
the result to be documented.

1. Measurement of the concentration of hazardous substances in air at the workplace

• Welding work stations: Alveolar dust fraction relevant
• Mixed work stations: Respirable dust fraction relevant
• Cancer-causing compounds require separate calculation

2. Exposure data to be compared with occupational exposure limit values (local regulations)

• If exceeded: take further or appropriate protective measures and carry out hazard assessment again

3. Document the results

 The occupational exposure limit values that apply depend on the materials used

• Iron, aluminum, magnesium, titanium oxide
  - General dust limit value  as per local regulations
• Substances with particularly toxic properties
  - Substance-specific limit values as per local regulations
• Carcinogenic substances such as chromium-IV compounds or nickel oxides
  - Excluded or minimum use

This means:

When the occupational exposure limits are exceeded, at least one protective measure is ALWAYS required!