Ammonia Leak Forces 1,000 to Evacuate : Accident: At least 4 people suffer nausea from the noxious cloud, which originated in a food storage plant in La Habra. Source of spill is unknown.

An ammonia cloud loomed over a wide stretch of the city Monday night, forcing more than 1,000 residents to evacuate their homes.

The leak from Christian Salvesen, a cold-food storage facility in the 300 block of Cypress Street, sent teams of Orange County sheriff’s deputies, hazardous-materials units and Fullerton and Brea police to the scene, said La Habra Police Sgt. Ray Breur.

“It’s still expanding,” Breur said late Monday night. “The situation is still ongoing. It’s not downscaling, it’s upscaling right now.”

The ammonia, used as a refrigerant, was detected about 6:30 p.m. in an area bounded by East La Habra Boulevard, East Lambert Road, Euclid Street and Harbor Boulevard, Breur said. The entire area was closed to traffic late into the night, police said.

Although ammonia fumes are not deadly, Breur said, “ammonia is a noxious gas. It has a strong odor and is an irritant to the lungs. In its concentrated form, it can overwhelm your oxygen supply and cause you to pass out.”

Two workers at the site reported nausea, and one was treated at Friendly Hills Regional Medical Center in La Habra and released. Two teen-agers in the evacuation area were vomiting, Breur said.

Police began evacuating residents from apartment and condominium complexes and surrounding homes about 7:30 p.m., going door to door and using loudspeakers. Those who could not leave their homes were advised to close their windows and doors and turn off the air conditioning. The evacuations continued after 10 p.m.

Brea Community Hospital and Friendly Hills Regional medical Center were placed on alert, although no other immediate injuries were reported.

Evacuees were directed to a local community center, where the Red Cross was prepared to house people if the evacuation continued overnight.

Chris Kaskawal, 25, who lives three blocks from the warehouse in the Smoke Tree condominiums with her husband and son, said, “I was busy putting everyone to bed when the officer came knocking on my door. . . . I was worried because I’m expecting, and I don’t want that stuff to get into my systems.”

Police had not determined the source of the spill or whether it was gas, liquid or both.

The warehouse stores frozen food for supermarkets. Breur described the warehouse as huge.

“Once we find the source, we’ll contain it and wait for it to dissipate,” Breur said.