42. German Federal Immission Control Act (BImSchV) for protection against legionella

The 42nd BImSchV (= 42nd Federal Immission Control Act – ordinance on evaporative cooling systems and wet separators) has been in force since 2018. The ordinance is based on the Federal Immission Control Act (BImSchG), more precisely the “Act for the Protection against Harmful Effects on the Environment Caused by Air Pollution, Noise, Vibration and Similar Processes”. The 42nd BImSchV regulates the operation of cooling systems, cooling towers and wet separators that use water and place it in contact with the environment. Since it is not a directive but an ordinance, the 42nd BImSchV must be implemented. Non-compliance is an administrative offense.

What are the objectives of the 42nd BImSchV?

The 42nd BImSchV focuses on the protection of public welfare and physical safety. The ordinance includes specific requirements for hygienically sound evaporative cooling systems, cooling towers and wet separators. If they are not operated properly, there is a risk that legionella will multiply in them and enter the outside air. The ordinance was enacted in response to several outbreaks of legionellosis caused by technical water systems in Germany. The 42nd BImSchV aims to prevent contamination of systems with legionella to avoid health risks for the population. Those most at risk are the personnel of companies with evaporation systems, for example during cleaning or maintenance work. Employers are obliged to protect their employees from health risks.

What does the 42nd BImSchV contain?

The 42nd Federal Immission Control Act is intended to counteract contamination of service water by microorganisms in the plants concerned. It prescribes regular inspections as well as microbiological examinations of the circulation water from evaporative cooling systems. Therefore, the ordinance includes various legal obligations, for example the preparation of a risk assessment and the definition of reference values for microbial contamination. The installation must be inspected at certain intervals by experts or accredited inspection bodies. If contamination with legionella is detected, there is an obligation to notify the responsible authority for prompt implementation of measures to prevent hazards. Rapid action is intended to prevent contaminated aerosols from entering the air and causing legionella infections. Microbiological findings and operational data of the cooling system must be recorded in the operating diary. When required by the competent authority or the expert during the inspection, the operating diary must be presented.

Which plants and for whom is the 42nd BImSchV relevant?

Evaporative cooling systems, cooling towers and wet separators are subject to the 42nd BImSchV if water is circulated, trickled or sprayed in them or otherwise comes into contact with the outside air. This means that both small systems used, for example, to cool buildings such as hotels, and cooling systems and wet separators in industrial plants are covered by the 42nd BImSchV. The implementation of the 42nd Federal Immission Control Act is obligatory for the plant operator, who is responsible for the plant on his behalf. In some cases, operator responsibility tasks can be delegated to service providers.

What are legionella?

Legionella are rod-shaped bacteria that occur naturally in bodies of water such as rivers or lakes and in groundwater. The ideal temperature for their reproduction is between 25°C and 45°C. With the appropriate heat, artificial water systems offer optimal growth conditions for legionella. These can be transmitted via pathogen-containing droplets that are airborne and inhaled. Typical sources of infection are, for example, showers, whirlpools or cooling towers.


Why can legionella be dangerous?

The inhalation of aerosols containing legionella poses a particular risk to high-risk groups. These include people with immune deficiencies, smokers and the elderly. If legionella multiply strongly, they can cause severe diseases, for example Legionnaires’ disease. This severe form of pneumonia presents with symptoms such as coughing, chills, and high fever. Legionnaires’ disease can last four weeks and in some cases is fatal.

Legionella can also cause Pontiac fever. With fever, discomfort, headache, aching limbs, and cough, the illness resembles the flu. It usually cures itself within a few days.

What role does VDI 2047 play regarding the 42nd BImSchV?

The 42nd Federal Immission Control Act on evaporative cooling systems and wet separators is based on the VDI cooling tower rules (VDI2047 Sheet 2). This series of guidelines provides the operator with recommendations on the hygienic operation of evaporative cooling systems, cooling towers and wet separators and defines peripheral conditions. Compliance with VDI 2047 is voluntary, but is considered a measure of the state of the art and is ideal proof of the hygienic operation of a system. Those who do not comply with the VDI guideline must prove that measures implemented instead were at least as effective. The 42nd Federal Immission Control Act explicitly refers to VDI 2047.

Legionella in paint shops

The 42nd Federal Immission Control Act is causing paint shop operators to fundamentally review their existing exhaust air treatment systems. If wet separators are used to separate the paint overspray, the ordinance now imposes stricter inspection and documentation requirements. Exposure of the environment to legionella must be ruled out in wet scrubbing systems with exhaust air.

Therefore, it is imperative to protect the environment of wet scrubber systems with exhaust air against legionella infestation. However, effectively treating the water in the system is a complex task. Wet scrubbing systems consume a lot of energy and cause high operating costs. They also pollute our environment through high water consumption and the use of coagulation chemicals. Paint shops with dry separation systems do not fall under the 42nd Federal Immission Control Act.

Industrial painting

Dry paint mist separation

Dry paint mist separation is the latest trend and is an effective and resource-saving alternative to wet scrubbing systems. Dry separation with modern filtration solutions does not require water or chemicals and is easy to handle. Conversion from wet to dry systems is also uncomplicated. With edrizzi paint mist separators, you benefit from a considerable overspray collection capacity and a separation efficiency of up to 97 percent. Cost-effective disposal by incineration is another plus.

edrizzi dry separators

Your contact for compliance with the 42nd BImSchV

Viledon filterCair optimizes painting processes in terms of qualitative and economic criteria, even when fixed service contracts and the use of Viledon filters are not involved. Its seven modules can be combined with one another to provide plant operators with optimum air quality management. This holistic approach increases process efficiency, improves painting results and also saves time and costs.

Take advantage of our hygiene consulting services to find out how you can meet the requirements of the BImSchV. The more stringent testing and documentation requirements of the 42nd BImSchV entail considerable additional work and costs for operators. To save you time and money, we will be pleased to assist you with our Viledon filterCair service packages for inspection and documentation. We offer customized filtration solutions for industrial painting and problem-specific advice at guaranteed fixed prices. Feel free to contact us.

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