Information on limit values for gases, particulate matter, and pollutants in the air we breathe.
Exposure limits are the subject of heated debate. Many people think they are too low, while others believe they are too high. However, the important thing is to be aware of them and to understand the context for yourself—for example, why exposure limits at work are often much higher than at home or outdoors. We have compiled this information for you here on exposure limits for gases, particulate matter, and pollutants in the air we breathe.
What are the legal limits for air pollutants? Find out here. For your health and well-being!
Here you’ll find a summary of the often complex definitions of limit values for air pollutants such as fine particulate matter, nitrogen dioxide, VOCs, formaldehyde, and ozone, as established by the Federal Environment Agency or the WHO. A distinction is made between limit values for specific pollutants outdoors, indoors, and in the workplace. In fact, it is often difficult to keep track of the big picture and determine when action is needed. The air-Q air analyzer helps you by monitoring these limit values for you.
-
Denomination PM 1 PM 2.5 PM 10 Daily Reference Value from the Federal Environment Agency - 15 µg/m³ - Daily Limit Value Set by the Federal Environment Agency - - 50 µg/m³ Annual Limit Set by the Federal Environment Agency - 25 µg/m³ 40 µg/m³
The Federal Environment Agency sets a daily limit value of 50 μg/m³ for PM10 fine particulate matter, which may be exceeded on no more than 35 days per year. In general, a maximum annual average of 40 μg/m³ applies. For the smaller PM2.5 particles, there are only non-binding target values of 25 μg/m³ set by the EU and the WHO. For even smaller particles—though much more dangerous—there are currently no limit values in place.More information✓ Compatible with the air-Q basic, the air-Q pro, the air-Q science, and the air-Q radon science.
-
Denomination EU Outdoor Air Limit Values Occupational Exposure Limits Interior Guidelines Long-Term Investments 40 µg/m³ - 40 µg/m³ Short-term securities 1-hour average emission limit value: 200 µg/m³,
3-hour average alarm threshold: 400 µg/m³- Average 1-hour precautionary level: 80 µg/m³,
average 1-hour hazard level: 250 µg/m³Work Shift - 950 µg/m³ -
The EU sets a limit value of 200 µg/m³ as the maximum hourly average. This limit may not be exceeded more than 18 times per year. If a value of 400 µg/m³ is exceeded for three hours, immediate action must be taken. The Federal Environment Agency sets guideline values for indoor spaces: 80 µg/m³ as the one-hour average and 40 µg/m³ as the annual average. The short-term alert threshold is set at 250 µg/m³.The occupational exposure limit (MAK) for NO₂ is set at 950 µg/m³, with numerous exceptions. However, this high limit applies specifically to workers exposed to high levels of nitrogen dioxide in the workplace—that is, not to those who work in offices. The Federal Environment Agency recommends setting the maximum weekly average at 40 µg/m³, even indoors.
More information✓ Compatible with air-Q pro as well as air-Q science
-
Denomination Carbon Dioxide Limit Values Recommendation from the Federal Environment Agency 1,000 ppm DIN 1946-2 limit value for good air quality 1,500 ppm MAK Values for Workstations 5,000 ppm
The Federal Environment Agency now recommends ventilating as soon as the carbon dioxide concentration exceeds 1,000 ppm. The maximum concentration in the workplace (MAK value) sets a limit of 5,000 ppm. The DIN 1946-2 standard, which is no longer in effect, specified a limit of 1,500 ppm. In children’s bedrooms, bedrooms, and crowded classrooms or meeting rooms, levels exceeding 5,000 ppm can be measured very quickly.More information✓ Compatible with the air-Q light, air-Q basic, air-Q pro, air-Q science, and air-Q radon science.
-
Denomination Carbon Monoxide Limit Values 24-hour guidance value from the Federal Environment Agency 4 mg/m³ (3.2 ppm) 8-hour guideline value from the Federal Environment Agency 10 mg/m³ (8 ppm) WHO recommendation: 1-hour value 25 mg/m³ (20 ppm) Valor MAK 35 mg/m³ (28 ppm) 15-minute indicative value from the Federal Environment Agency 100 mg/m³ (80 ppm) WHO recommendation: 15-minute value 85 mg/m³ (68 ppm)
The Federal Environment Agency sets a 24-hour average limit of 4 mg/m³ for carbon monoxide. The maximum workplace concentration (MAK value) for carbon monoxide is set at 35 mg/m³; MAK values do not apply to pregnant women or people with pre-existing medical conditions. The WHO recommends that concentrations exceeding 25 mg/m³ should not be inhaled for more than one hour, and concentrations up to 85 mg/m³ should not be inhaled for more than 15 minutes. The Federal Environment Agency is somewhat less strict in this regard, setting the limit at 100 mg/m³.
More information✓ Compatible with the air-Q basic and the air-Q pro, as well as the air-Q science
-
Denomination Oxygen Limit Values DGUV Standard 113-004 for Work in Silos and Confined Spaces 17 %
In Germany, there are no legal limit values for oxygen. DGUV Standard 113-004, issued by the German statutory accident insurance agency for occupational safety, specifies an oxygen concentration of 17 percent. The amount of oxygen still present in exhaled air is 16 percent.
More information✓ Compatible with air-Q science and the individual oxygen sensor
-
Denomination Ozone Limit Values Maximum 8-hour value from the Federal Environment Agency 120 µg/m³ Information summary from the Federal Environment Agency (1-hour average) 180 µg/m³ Federal Environment Agency alert level (1-hour average) 240 µg/m³
The Federal Environment Agency sets a maximum 8-hour ozone level of 120 µg/m³ (60 ppb), which may be exceeded on no more than 25 days per calendar year. However, the UBA recommends that this level not be exceeded at all. When levels reach 180 µg/m³, the public must be notified; when levels reach 240 µg/m³, an ozone alert must be issued.There is currently no occupational exposure limit (AGW, formerly MAK). Since an AGW for ozone has not yet been established, the former MAK value of 200 µg/m³ serves as a non-binding guideline. For offices, the limit values set by the Federal Environment Agency apply.
More information✓ Compatible with the air-Q pro and the air-Q science
-
Denomination Sulfur Dioxide Limit Values 1-Hour Threshold Value 350 µg/m³ Daily Limit 125 µg/m³ Annual/Winter Limit Value 20 µg/m³
The EU has established the following limit values for sulfur dioxide: the hourly limit value is 350 µg/m³, and the daily limit value is 125 µg/m³. In addition, an alarm threshold of 500 µg/m³ applies to sulfur dioxide. The occupational exposure limit (MAK value) for sulfur dioxide is set at a concentration of 2.5 mg/m³ (1,000 µg/m³ or 1 ppm).
More information✓ Compatible with the additional sulfur dioxide sensor.
-
Denomination Radon Limit Values Euratom Standards at the EU Level 300 Bq/m³ annual average Estimated planning value for new buildings 200 Bq/m³ annual average WHO Recommendation 100 Bq/m³
German radiation protection law establishes the reference value for radon concentrations. Indoors, the limit value of 300 becquerels per cubic meter (Bq/m³) applies, which corresponds to 300 decays per second per cubic meter of air. Upon request, the landlord or employer must be able to verify these values. The German Commission on Radiation Protection (SSK) recommends ventilating when levels reach 250 Bq/m³ and reducing the concentration permanently to below 100 Bq/m³, in line with the World Health Organization (WHO). If levels exceed 1,000 Bq/m³, radon remediation should be carried out.More information✓ Compatible with the air-Q radon and the air-Q radon science.
-
Denomination Absolute Air Humidity Limit Values General recommendation: minimum value 6.9 g/m³ General recommendation: maximum value 10.4 g/m³
There are no established limit values for absolute humidity. Values between 6.9 and 10.4 g/m³ are recommended; at room temperature, these values mark the boundary between air that is too dry and air that is too humid. However, at lower or higher temperatures, these values can quickly become uncomfortable.
More information✓ Compatible with the air-Q light, air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Denomination Relative Humidity Threshold Values General recommendation: minimum value 40 % General recommendation: maximum value 60 %
There are no legal limits for relative humidity. In indoor spaces, a relative humidity of between 40% and 60% is recommended. A range of 30% to 70% relative humidity is considered acceptable. If the relative humidity exceeds 95% or falls below 23%, most people find the air uncomfortable.
More information✓ Compatible with the air-Q light, air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Denomination Methane Limit Values Lower Explosive Limit (LEL) 29 g/m³ (equivalent to 4.4% by volume)
Since methane is not toxic to humans, no limit values have been established for this gas. However, methane’s high flammability poses a significant risk. A methane concentration of 29 g/m³ is considered the lower explosive limit (LEL), which is equivalent to 4.4% by volume. Above this value, the flame propagates through the gas mixture completely spontaneously upon ignition (explosion).Methane is also known as a dangerous greenhouse gas and, as such, contributes to human-induced climate change. In recent years, the concentration of methane in the atmosphere has been rising rapidly.
More information✓ Measurable (via the VOC gas group) with the air-Q light, air-Q basic, and air-Q pro, as well as the air-Q science or using the standalone methane sensor.
-
Denomination Formaldehyde Limit Values Federal Institute for Risk Assessment (BfR) 0.1 ppm (equivalent to 124 µg/m³) WHO Recommendation 0.08 ppm (equivalent to approximately 100 µg/m³) MAK (maximum workplace concentration) 0.3 ppm (equivalent to 370 µg/m³)
The Federal Institute for Risk Assessment (BfR) sets a maximum concentration of formaldehyde at 0.1 ppm (parts per million). The World Health Organization (WHO) recommends a maximum of 0.08 ppm as the formaldehyde limit value. In the workplace, the MAK value of 0.3 ppm applies.More information✓ Can be measured using the air-Q Formaldehyde Special, the air-Q Pro, the air-Q Science, or the standalone formaldehyde sensor. Formaldehyde is also detected by the VOC sensor as part of the total VOC reading, which is included in all air-Q models (air-Q light, air-Q basic, and air-Q pro).
-
Denomination Atmospheric Pressure Limit Values without defined limit values -
There are no relevant limit values for atmospheric pressure in normal environments. Significant deviations from the normal pressure of 1 hPa can also occur in the workplace. Special permits are required for pressures below 0.73 hPa and above 3.6 hPa. Even deviations of 0.1 hPa from normal atmospheric pressure can cause significant health problems, and certain groups of workers can no longer be employed.
More information✓ Compatible with the air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Denomination Noise Limit Values Federal Act on Protection Against Environmental Pollution (TA Lärm) — Interior Day: 35 dB
Night: 25 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Thermal and Recreational Areas Day 45 dB
Night 35 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Purely Residential Areas Day: 50 dB
Night: 35 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Mixed-Use Zones Day: 60 dB
Night: 45 dBWHO Recommendation for Wind Turbines Near Residential Areas Day 45 dB
The official TA Lärm (Technical Instruction on Noise Protection) establishes maximum levels for indoor spaces (25 dB at night, 35 dB during the day). Outdoors, different limit levels apply depending on the area; in purely residential areas, for example, 50 dB during the day and 35 dB at night. The WHO has formulated a series of recommendations for specific noise sources and areas. In the vicinity of wind turbines, the WHO recommends a maximum noise level of 45 dB; road traffic noise should be kept below 53 dB during the day and 45 dB at night, always measured outdoors. For noise protection in the workplace, the Regulation on Protection Against Noise and Vibrations at Work (LärmVibrationsArbSchV) applies. This regulation establishes different limit values depending on the type of activity, the duration, and the specific location of noise exposure. For offices, for example, there are no specific limit values.
More information✓ Compatible with the air-Q light, the air-Q basic, and the air-Q pro, as well as the air-Q science
-
Denomination Noise Limit Values Federal Act on Protection Against Environmental Pollution (TA Lärm) — Interior Day: 35 dB
Night: 25 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Thermal and Recreational Areas Day 45 dB
Night 35 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Purely Residential Areas Day: 50 dB
Night: 35 dBFederal Act on Protection Against Environmental Pollution (TA Lärm) — Mixed-Use Zones Day: 60 dB
Night: 45 dBWHO Recommendation for Wind Turbines Near Residential Areas Day 45 dB
The official TA Lärm (Technical Instruction on Noise Protection) establishes maximum levels for indoor spaces (25 dB at night, 35 dB during the day). Outdoors, different limit levels apply depending on the area; in purely residential areas, for example, 50 dB during the day and 35 dB at night. The WHO has formulated a series of recommendations for specific noise sources and areas. In the vicinity of wind turbines, the WHO recommends a maximum noise level of 45 dB; road traffic noise should be kept below 53 dB during the day and 45 dB at night, always measured outdoors. For noise protection in the workplace, the Regulation on Protection Against Noise and Vibrations at Work (LärmVibrationsArbSchV) applies. This regulation establishes different limit values depending on the type of activity, the duration, and the specific location of noise exposure. For offices, for example, there are no specific limit values.More information✓ Compatible with the air-Q light, the air-Q basic, and the air-Q pro, as well as the air-Q science
-
Denomination Ambient Temperature Limits Recommendation from the Federal Environment Office - Housing 21 °C to 23 °C Recommendation from the Federal Environment Agency - Offices 21 °C to 22 °C Recommendation from the Federal Environment Agency - Children's Room 21 °C to 23 °C Recommendation from the Federal Environment Agency - Bedroom 16 °C to 18 °C Maximum value according to the Workplace Directive (ASR) - Offices 26 °C
The Federal Environment Agency issues recommendations for room temperature based on the use of the space (for example, living areas 21 to 23 °C, children’s rooms and bathrooms 23 °C, bedrooms 16 to 18 °C). For offices, a room temperature between 21 and 22 °C is recommended. According to the Workplace Directive (ASR), the maximum temperature in workspaces must not exceed 26 °C; otherwise, the employer is required to take measures.More information✓ Compatible with air-Q light, air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Area of Activity / Use of Space Minimum illuminance value E (lx) Precision work, e.g., sanding decorative elements, color checks, assembly work 1000 lx Writing, reading, data processing 500 lx Files 200 lx Break rooms, waiting rooms, locker rooms 200 lx
For workplaces in Germany, there are recommendations regarding the type and direction of lighting and the corresponding measures to protect the eyes from fatigue.
In its document “Technical Rules for Workplaces,” the Federal Institute for Occupational Safety and Health (BAuA) sets forth the following minimum values in May 2023 regarding “lighting and visual contact”:
More information✓ Can be used as an additional sensor with the air-Q Science
-
Denomination VOC Limit Values Federal Environment Agency - hygienically safe <1 mg/m³ – de 150 a 400 ppb (partes por billón) Federal Environment Office - Remarkable in Terms of Hygiene 1 to 3 mg/m³ – 400 to 1,200 ppb Federal Environment Agency - a health concern 3 to 10 mg/m³ – 1,200 to 4,000 ppb Federal Environment Agency - Unsanitary and Unacceptable >10 mg/m³ – more than 4,000 ppb
The Federal Environment Agency issues recommendations regarding the presence of volatile organic compounds (VOCs), ranging from health-wise harmless (less than 1 mg/m³ – less than 150 ppb) to health-wise noticeable (between 1 and 3 mg/m³ – 150 to 1,300 ppb) and health-wise concerning (between 3 and 10 mg/m³ – 1,300 to 4,000 ppb) to health-wise unacceptable (more than 10 mg/m³ – more than 1,500 to 4,000 ppb). Many legally relevant sources specify mg/m³ as the unit. However, what is actually measured is a mixture of numerous substances with different molecular weights (also referred to as TVOC), whose volumetric proportion in the air is expressed in ppb (parts per billion) or ppm (parts per million). In Germany, to date, there is only a legal regulation setting limit values for VOCs in workplaces that are particularly exposed during production processes.More information✓ Compatible with air-Q light, air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Denomination Dew Point Limit Values General recommendation: minimum value 9 °C General recommendation: maximum value 15 °C More information✓ Compatible with air-Q light, air-Q basic, air-Q pro, air-Q science, air-Q radon, and air-Q radon science.
-
Denomination Nitrous Oxide (N₂O) Limit Values Occupational Exposure Limit (AGW) (DFG MAK) 100 ppm (180 mg/m³) More information✓ Compatible with the air-Q Science or the standalone nitrous oxide ("laughing gas") (N₂O) sensor.
-
Denomination Hydrogen Sulfide Limit Values Occupational Exposure Limit (AGW) 5 ppm (equivalent to approximately 7 mg/m³) MAK (maximum workplace concentration) 10 ppm (equivalent to approximately 14 mg/m³) More information✓ Compatible with air-Q pro as well as air-Q science
-
Denomination Ammonia Limit Values Recommendation from the Federal Environment Agency Regarding Outdoor Air Quality <700 µg/m³ (1 ppm) Threshold value according to the Animal Welfare Regulation for Livestock (TierSchNutztV) 14,000 µg/m³ (20 ppm) Occupational Exposure Limit (AGW) 14,000 µg/m³ (20 ppm) More information✓ Compatible with the air-Q Science or the standalone ammonia sensor.
-
Since the gas has no direct effects on human health, no limit values have been established.
Denomination Hydrogen Limit Values Lower flammability limit 4% Upper flammability limit 76% Lower Explosivity Limit 18% More information✓ Compatible with the air-Q Science or the standalone hydrogen sensor.
-
Denomination Chlorine (Cl₂) Limit Values Olfactory shadow 0.02 ppm - 1 ppm Occupational Exposure Limit (AGW) 0.5 ppm (= 1.5 mg/m³ of air) More information✓ Compatible with the air-Q Science or the individual chlorine (Cl₂) sensor.
- More information
✓ Measurable with the air-Q Science upon request.
- More information
✓ Measurable with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Compatible with the air-Q Science or the individual HF sensor.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
- More information
✓ Available with the air-Q Science upon request.
-
Unlike many air pollutants, there is no fixed, universally applicable limit value for infrasound. In Germany, low-frequency noise and noise emissions are primarily assessed in accordance with the TA Lärm and the DIN 45680 standard. The focus is not on isolated general values, but rather on the frequency spectrum, sound pressure level, measurement location, and duration of exposure. Extremely low frequencies, below 20 Hz, are referred to as infrasound and must be recorded using appropriate measurement techniques, as conventional dB(A) values often fail to adequately reflect this exposure.
More information✓ Available with the air-Q Science upon request.
