An ammonia leak requires a response within minutes because the gas irritates the eyes and respiratory tract and can damage the lungs hours after exposure. Therefore, companies that use ammonia for refrigeration need detection, alarm systems, emergency plans, and trained personnel before any incident occurs. The case in Penha, on the northern coast of Santa Catarina, shows how quickly a failure can affect those outside the plant.
What happened in Penha and why is the case of interest to the industry?
On the night of September 16, 2026, ammonia used for refrigeration at a fish processing company leaked in Penha (SC). According to local press, about 300 people left a nearby church during a service, and nearby residents left their homes as a precaution.
In addition, five people received emergency room treatment for nausea, vomiting, dizziness, and difficulty breathing. According to reports, firefighters brought the situation under control in about 40 minutes after closing the valve. The technical cause has not yet been released.
Nevertheless, the incident serves as a clear warning: there was no one at the company, and the impact reached the neighborhood first. In other words, the risk of ammonia extends beyond the plant's boundaries.
Why does ammonia require extra attention?
Anhydrous ammonia (NH₃) is a toxic gas, identified by the UN with the number 1005, and widely used as a refrigerant in refrigerators, dairies, and cold storage facilities. Upon contact with moisture in the eyes, skin, and mucous membranes, it forms ammonium hydroxide, an alkaline and corrosive solution.
In this context, some points deserve attention:
- The sense of smell fails as an alarm. The odor appears at around 5 ppm (parts per million), but prolonged exposure causes olfactory fatigue and reduces the perception of the gas.
- The eyes are the most sensitive target. According to CHEMM, a reference center of the United States Department of Health, ammonia penetrates and damages the eyes more easily than other alkalis.
- The effects may be delayed. Lung injury can develop over several hours, including pulmonary edema.
- The liquid form burns and freezes. Contact with liquefied ammonia causes burns and frostbite on the skin.
Regarding limits, Annex 11 of NR-15 sets 20 ppm as the tolerance limit in Brazil. However, NIOSH, the American occupational health institute, considers 300 ppm to be the concentration that is immediately dangerous to life or health (IDLH).
What does NR-36 require of those who work with ammonia?
NR-36, a regulation from the Ministry of Labor and Employment for meat processing plants, defines specific measures for refrigeration systems using ammonia. Therefore, it also serves as a benchmark for other plants that use the gas.
Among the requirements, the standard stipulates:
- early detection of leaks at critical points, linked to an alarm system;
- control panel of the refrigeration system;
- safety showers and eyewash stations;
- emergency exits must be unobstructed and clearly marked.
- emergency response plan with scenarios, team, evacuation routes and containment procedures;
- simulated exercises must be recorded at least once a year.
Furthermore, whenever there is a leak in the workplace, the company must measure the ammonia concentration at the site. For design and operation, ABNT NBR 16069:2018 complements the standard with safety requirements for refrigeration systems.
How to act in the first few minutes after an ammonia spill.
The priority is to move people away from the gas cloud and stop contact with the substance as quickly as possible. Then, the team must follow the plant's emergency plan, without improvising.
Based on guidelines from CETESB, the São Paulo state environmental agency, and NR-36 (Brazilian Regulatory Standard 36), the initial response usually follows this order:
- Activate the alarm and evacuate the affected area, always against the wind.
- Call the Fire Department and the internal emergency team.
- Stop the leak, whenever it is possible to do so safely and with appropriate PPE (personal protective equipment).
- Isolate the area and keep people away, including neighbors.
- Decontaminate the eyes and skin of victims with thorough and immediate washing, in accordance with the SDS (Safety Data Sheet) and company protocol.
- Refer exposed individuals for medical evaluation, even if they have no apparent symptoms.
The last step deserves special attention, as lung damage can occur hours later.
Team preparedness before the incident.
The response in the first few seconds depends on what the team already knows how to do. Therefore, a written procedure without practical training tends to fail under pressure.
In practice, this means simulating real-life scenarios, testing alarms and escape routes, checking access to eyewash stations, and training in the care of a victim who cannot open their eyes. Similarly, the plan needs to consider night shifts and periods without operations, as in the case of Penha.
Frequently Asked Questions
What is the ammonia exposure limit in Brazil?
Annex 11 of NR-15 establishes a tolerance limit of 20 ppm for ammonia. Above this value, exposure requires control measures by the company.
Is the smell of ammonia enough to identify a leak?
No. Although the odor is perceived at low concentrations, continuous exposure causes olfactory fatigue. Therefore, NR-36 requires detectors connected to alarms at critical points.
How long after exposure can symptoms appear?
Eye and respiratory tract irritation is usually immediate. On the other hand, lung damage can develop over several hours, which justifies medical evaluation for all those exposed.
Conclusion
The ammonia leak in Penha demonstrates that the risk posed by a refrigeration system can reach workers, neighbors, and response teams within minutes. Therefore, detection, an emergency plan, and a trained team are essential components that must be in place before an incident occurs.
In this regard, Risco Químico supports companies with practical training in chemical safety, focused on response within the first 60 seconds after exposure, including the DIPHOTERINE® protocol for skin and eye decontamination.