(KRON) — Twenty-one people have been exposed in a hazardous materials incident on the 1100 block of Island Drive in Redwood Shores, according to the Redwood City Fire Department. The incident involved an accidental chemical release in a clean room, Redwood City FD said.

The leaked gas was later identified by Redwood City FD as Freon. Crews at the scene determined that a faulty AC unit was the source of the leak.

The materials are not related to biohazard materials. No evacuations or shelter-in-place orders have been given for the broader community. Of the 21 people exposed, 16 have shown no symptoms.

The remaining five are receiving treatment. They complained of nausea, and two had bloody noses, the Redwood City Fire Department said. Nobody was hospitalized.

Fire officials tested for many different gases and only Freon was found. An HVAC unit failed and pumped Freon into the workplace, per RCFD. The levels were not hazardous.

Crews are still trying to determine which HVAC unit failed. Fire officials are still unsure if people will be allowed back into the building on Tuesday.

Emergency services are on-site and the building has been evacuated, according to firefighters. Fire authorities are inspecting the building methodically, Redwood City FD said. Due to the nature of the incident, it will take time for firefighters to finish the inspection.

This is a developing story. Check back for updates.