For operators in the metalworking industry who are required to control welding fumes in the workplace, clear limit values are not optional, but mandatory. Legal requirements for protection against welding fumes have been tightened in recent years, and from 2026 onwards, specific limit values will apply that every company must know and comply with. This article answers the most important questions about limit values, standards, and technical protective measures.
What are the limit values for welding fumes, and why do they apply?
Limit values for welding fumes are legally defined maximum concentrations of airborne pollutants that must not be exceeded in the workplace. They protect employees from acute and chronic health problems that can result from inhaling metal oxides, particles, and gaseous components.
Welding fumes are not a uniform substance. They consist of a mixture of fine particles and gases, the composition of which depends on the base material, the filler material, and the welding process. Welding unalloyed steels primarily produces iron oxides. Welding stainless steel or chromium-containing materials also produces carcinogenic chromium(VI) compounds and nickel oxides. These differences necessitate a differentiated approach to limit values.
A typical challenge: Many companies underestimate the danger because welding fumes are visible to the naked eye and appear harmless. In reality, the particles that pose a health risk are often smaller than 1 micrometer and penetrate deep into the lungs.
What legal limits will apply to welding fumes from 2026 onwards?
The general limit value for respirable dust (A-dust) is 1,25 mg/m³. For welding fumes from stainless steel and other chromium-containing alloys, an additional limit value of 0,010 mg/m³ applies for chromium(VI) compounds. These values are defined as occupational exposure limits (OELs) in TRGS 900.
According to TRGS 900, the occupational exposure limit is the time-weighted average concentration of a substance in the air at the workplace, based on an eight-hour shift. For carcinogenic substances such as chromium(VI), there is no safe limit value, which is why the principle of minimization applies. This means that exposure must be reduced as much as technically possible, even if the limit value is formally met.
For nickel compounds, an occupational exposure limit (OEL) of 0,006 mg/m³ (inhalable fraction) applies. Manganese and its compounds, which are produced during the welding of structural steels, are limited to 0,02 mg/m³ (respirable). These limits demonstrate that welding fumes require a differentiated hazard assessment, not a blanket approach.
What does TRGS 528 regulate regarding protection against welding fumes?
TRGS 528 is the central technical rule for welding work. It specifies the requirements of the Hazardous Substances Ordinance and defines which protective measures companies must implement when welding, cutting, and related processes. It is considered the most important basis for action for operators and safety officers.
Protection level model of TRGS 528
TRGS 528 uses a protection level model. Depending on the hazard class of the base material and the welding position, different measures are prescribed. When working with unalloyed steels under favorable conditions, adequate ventilation may suffice. For stainless steel or in confined spaces, technical extraction measures directly at the source are mandatory.
Priority of protective measures
TRGS 528 follows the STOP principle: Substitution before technical measures, before organizational measures, before personal protective equipment. Technical measures such as extraction systems therefore take precedence over respiratory protective devices. According to TRGS 528, personal protective equipment is only considered a supplementary measure, not a replacement for a functioning extraction system.
What is the difference between A-dust and E-dust in welding fumes?
Respirable dust (A-dust) refers to particles that penetrate as far as the alveoli in the lungs. Inhalable dust (E-dust) includes all particles that can be inhaled through the mouth and nose. For welding fumes, the A-dust limit of 1,25 mg/m³ is particularly relevant, as fine welding fume particles typically penetrate deep into the respiratory tract.
This difference has direct implications for measurement technology and hazard assessment. Workplace measurements must be fraction-specific. A device that only detects inert dust (E-dust) does not provide sufficient information for welding fumes. For carcinogenic accompanying substances such as chromium(VI), the inhalable fraction is measured, as these compounds can already have a harmful effect in the upper respiratory tract.
For the interpretation of Extraction systems for welding applications This distinction is crucial. The filter system must be capable of reliably removing respirable particles. Standard filters without sufficient filtration efficiency for fine particles do not meet the requirements of TRGS 528.
How is compliance with the limit values measured in the workplace?
Compliance with the limit values is verified through personal or stationary measurements. For personal measurements, the employee wears a sampling device in the breathing zone. The sample is then analyzed in a laboratory. Measurements must be carried out by qualified personnel or accredited testing laboratories.
Who is required to take measurements?
According to the Hazardous Substances Ordinance, employers are obligated to verify compliance with limit values as part of their risk assessment. For activities involving carcinogenic substances such as chromium(VI), there is an increased obligation to document the process. The German Social Accident Insurance (DGUV) recommends repeating measurements regularly, especially when processes, materials, or room conditions change.
Risk assessment as a basis
Before any measurements can be taken, a risk assessment must be conducted. This assessment determines which substances are produced, in what quantities, and under what conditions. Only on this basis can it be decided whether a measurement is necessary or whether empirical data from comparable activities can be used. Companies can access exposure databases maintained by the employers' liability insurance associations for this purpose.
Which extraction measures help to ensure compliance with limit values?
The most effective measure for complying with welding fume limits is capture directly at the source. Extraction systems with capture elements such as extraction torches, capture nozzles, or extraction tables prevent welding fumes from entering the ambient air. Downstream hall ventilation alone is insufficient for intensive welding operations.
Choosing the right extraction strategy depends on the welding process, the room layout, and the number of welding stations in operation simultaneously. Decentralized, single-station systems are suitable for changing workstations. Centralized extraction systems are more economical and efficient for multiple fixed welding stations. Crucially, the filter system must be suitable for the substances being extracted, especially carcinogenic byproducts.
According to TRGS 528: Extracted air may only be returned to the work area if the filter system demonstrably has sufficient separation efficiency for the pollutants present. For fumes containing chromium(VI), a HEPA filter or an equivalent filter medium is generally required. Further information on suitable Filter systems and extraction systems help with the specific selection.
How ULMATEC helps with compliance with welding fume limits
For operators in metal manufacturing who must reliably comply with welding fume limits according to TRGS 528 and TRGS 900, we develop and manufacture industrial extraction systems specifically designed to meet these requirements. Our systems cover the entire process: from capture at the source and filtration to the safe recirculation or discharge of the cleaned air.
What we specifically offer:
- Extraction systems for welding fumes, soldering fumes and plasma cutting fumes with suitable filter media for fine particles and carcinogenic accompanying substances
- Central extraction systems for air volume flows of 3.000 to 250.000 m³/h for companies with multiple welding stations
- Modular system with over 10 million variants for different applications and room situations
- Systems that combine air purification, air conditioning and heat recovery
- Complete technical documentation for risk assessment and official verification
- Eligibility for funding according to BAFA and KfW
All our systems comply with applicable standards, including TRGS 528, and are designed, manufactured, and installed by experienced specialists. If you would like to know which extraction system is suitable for your welding application, Contact us and receive a concrete assessment for your business.