H₂S in laboratories : vital detection, Dalemans solutions
Invisible and deadly from just a few ppm, H₂S poses a threat in laboratories and industry. Discover how Dalemans solutions ensure reliable and compliant detection.
Hydrogen sulfide (H₂S) : an underestimated danger in laboratories
Colorless and known for its characteristic rotten egg smell, hydrogen sulfide (H₂S) can quickly become a silent killer in confined environments, especially in laboratories and industry. Highly toxic, flammable, and corrosive, this gas is generated in many chemical or biological reactions.
Contexts and sources of emission
In laboratories, H₂S can be :
- Released during chemical reactions involving sulfides or acids,
- Present in biological samples (due to decomposition),
- Used as a reactive gas in specific protocols,
- Emitted during the handling of organosulfur compounds.
It can also be present in areas where organic matter decomposes, such as marshes, sewers, and wastewater treatment plants.
Without reliable detection, exposure to H₂S can be immediate and dramatic. Start assessing the risk in your lab today.
H₂S : toxicity, exposure limits, and health risks
H₂S acts rapidly on the central nervous system. Just a few seconds of exposure can cause severe symptoms :
- 0.01 to 1 ppm : olfactory detection threshold
- 10 to 20 ppm : eye irritation, coughing
- 50 to 100 ppm : loss of smell, nausea
- 200 to 300 ppm : respiratory distress
- > 500 ppm : immediate collapse, respiratory arrest, death
Source : National Institute for Research and Safety (INRS), Toxicology Sheet No. 32 - Hydrogen Sulfide
Note : The European short-term occupational exposure limit (STEL) is generally set at 10 ppm over 15 minutes.
H₂S detection solutions tailored to laboratory environments
Since 1985, Dalemans has been providing reliable and innovative gas detection solutions, designed for demanding environments such as laboratories. Thanks to cutting-edge technology and products tested under real-world conditions, the safety of your facilities is assured.


Field experience : Dalemans' expertise in the face of H₂S risk
During our maintenance operations on fixed hydrogen sulfide gas detection systems, our Field Service Department Manager, Patrick Belloli, highlights the importance of preventive measures :
“Our technicians are systematically equipped with portable detectors, with alarm thresholds set at 5 ppm and 10 ppm. This allows early detection even when the rotten egg smell of H₂S becomes noticeable. We operate in full compliance with current safety standards and certifications.”
See our safety commitments : Dalemans | Safety
Field experience reinforces the importance of both fixed and portable equipment in high-risk environments.
Recommended H₂S Detector Models
D•420 Detector : the versatile benchmark
The D•420 is a fixed, versatile and robust detector, designed for laboratories, parking garages or technical areas. For H₂S detection, it uses a high‑precision electrochemical cell. Its LCD screen displays real‑time concentration and it transmits data to an alarm control panel via a 4–20 mA current loop.
Key features :
- Compatible with U•C2, U•V6 and S•Lx control panels
- IP65 sealed, explosion‑proof, flame‑retardant enclosure
- Intuitive touch keypad
- Easy sensor cell replacement
Available in H₂S version, with measurement ranges adapted to specific laboratory hazards.
DAT 420 ATEX Detector : solution for hazardous zones
For laboratories located in ATEX zones, the DAT 420 is the detector you need. ATEX II 2G and 2D certified, it is designed to withstand explosive atmospheres (Zone 1 and 2), providing reliable H₂S detection.
Main characteristics :
- High‑precision electrochemical sensor
- IP6X explosion‑proof aluminium enclosure
- FTZU 09 ATEX 0074X certification
- 4–20 mA output for secure signal transmission
Ideal for laboratories handling explosive materials or operating in critical environments.
Alarm Control Panels : reliable and continuous H₂S monitoring
U•C2 Control Panel : compact and efficient
The U•C2 is a reliable safety hub designed to monitor toxic gas leaks like H₂S, with up to 4 configurable alarm thresholds per channel.
Main features :
- 2 detection inputs
- Automatic ventilation control, audible alarms, strobe lights
- User‑friendly interface with secure password protection
- IP65 wall‑mounted enclosure
Perfect for small‑ to medium‑size laboratories.
U•V6 Control Panel : intelligence and modularity
With its 6 inputs, the U•V6 is designed for medium‑sized installations. It enables active ventilation management and can control alarms, gas valves or send commands to a BMS.
Highlights :
- 4 alarm thresholds per channel
- 5 programmable relays + 1 fail-safe relay
- Full integration of D•420 and DAT 420 detectors
- Suitable for commercial, industrial buildings and parking structures

S•Lx Control Panel : flexibility and connectivity
The S•Lx panel is designed for more complex gas detection systems with numerous measurement points. Its integrated touchscreen offers clear and precise risk-level displays. The built‑in LED strip provides a visual warning before entering a laboratory area.
Advantages :
- Reduces wiring thanks to CAN bus lines (shielded 2 × 2 × 0.75 mm² cable)
- Event logging and display
- Data recording (SD card)
- Supports up to 16 analog 4–20 mA inputs and up to 240 CAN bus inputs
Choosing Dalemans means choosing peace of mind
Dalemans is not just a supplier : it has been a trusted safety partner for over 35 years.
Your benefits :
- Recognized technical expertise in gas detection
- Tailored support : site survey, installation, maintenance
- Compliance with European standards (ATEX, IEC, etc.)
- Scalable solutions : compatible with BMS and connected equipment
- Responsive after-sales service and extended warranty
Conclusion : your safety is our priority
H₂S, as discreet as it is dangerous, requires fast, reliable and compliant detection. With its D•420 and DAT 420 detectors and its intelligent U•C2 and U•V6 control panels, Dalemans offers a complete range of professional solutions to secure laboratories.
Don’t let the invisible become a threat. Trust Dalemans to protect your teams and your facilities.
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