Warehouse Fire Smoke Warning Extended: How To Track Air Quality In Your Neighborhood

LOS ANGELES, CA — Smoke from the days-long Boyle Heights warehouse fire continued affecting air quality across the Los Angeles region Monday, prompting air regulators to extend a particle pollution advisory through Tuesday afternoon.

The South Coast Air Quality Management District's advisory was in effect from 9:30 a.m. Monday until 12:30 p.m. Tuesday. The fire began June 17 at a cold-storage warehouse and firefighters have worked continuously in an effort to extinguish it, officials said.

As of Monday morning, the fire was still actively producing smoke, and firefighting operations were expected to continue, South Coast AQMD said. Monitors and sensors showed PM2.5 levels had improved beginning Sunday afternoon in Central and Southeast Los Angeles, the San Gabriel Valley and the San Fernando Valley, but conditions near the fire remained worse.

'Very Unhealthy' Air

Air quality in Boyle Heights reached the “Very Unhealthy” category throughout the day Sunday, while other areas were generally in the Good to Moderate range for fine particulate pollution, according to the AQMD.

The agency warned that smoke impacts will depend on fire activity and could shift quickly by neighborhood. Smoke was expected to have the greatest impact Monday afternoon north and east of the fire, including East Los Angeles and the San Gabriel Valley, with significant impacts likely to continue immediately around Boyle Heights.

By Monday evening, light winds could allow smoke to spread in multiple directions, potentially affecting the broader Los Angeles metropolitan area, regulators said. By Tuesday morning, smoke impacts were expected to remain focused northeast and east of the fire, including Boyle Heights, East Los Angeles and the San Gabriel Valley.

Ash may also fall across the area, South Coast AQMD warned. Larger ash particles and debris may not be reflected in Air Quality Index readings, so residents were urged to take precautions if they smell smoke or see smoke or ash, even if local AQI readings appear lower.

The agency offered these suggestions to those in affected areas:

• stay indoors with windows and doors closed
• avoid strenuous outdoor activity
• run air conditioning or an air purifier if available, and avoid swamp coolers or whole-house fans that pull outdoor air inside

Fire officials said Monday that air quality concerns remained widespread, but the U.S. Environmental Protection Agency and South Coast AQMD had not detected anything beyond normal combustible material typical after a fire.

SEE ALSO: Warehouse Company Reveals Likely Origin Of Boyle Heights Fire

No shelter-in-place or evacuation orders were in effect Monday.

The fire spread rapidly Wednesday across solar panels on the roof of the food-storage warehouse. An ammonia leak developed inside the building, and thick smoke prompted shelter-in-place orders for nearby residents and businesses, according to the Los Angeles Fire Department. Those orders were later lifted.

Lineage, the operator of the warehouse, issued a statement Monday suggesting that the fire's origins were connected to the solar panels.

"We want our neighbors to know that Lineage does not own the building or its rooftop solar array. We are the tenant-operator of the warehouse building and lease the roof to a third-party solar company, which is responsible for operating and maintaining the array. We believe the fire originated on the roof on Wednesday while the company's subcontractors were servicing the solar array," the statement reads.

Firefighters have had to tear down walls to reach areas deep inside the warehouse. LAFD public information officer Capt. Jacob Raabe told KTLA on Monday morning that crews hoped to apply a large amount of water to the center of the building to put out the remaining fire.

Drones and a firefighting robot have also been used to help crews map heat and attack inaccessible areas. Fire officials said Sunday that many solar panels had been de-energized and multiple lithium-ion batteries had been removed, reducing hazards for firefighters and the surrounding community.

Meteorologist Weighs In

NBC Los Angeles meteorologist David Biggar, writing in a Reddit post, said smoke conditions can vary sharply from block to block because AQI readings reflect conditions at a specific sensor location and time. He also noted that morning conditions can worsen when a marine-layer inversion traps smoke closer to the ground, while shifting winds can push smoke into different parts of the basin — which explains some residents' observations that the smoke was at its worst during the morning in recent days.

Biggar suggested residents use the U.S. Air Quality Index's map to keep track of up-to-date air quality measurements on a neighborhood level.

Two emergency shelter locations were opened for people affected by the fire: Pecan Recreation Center at 145 S. Pecan St. and City Terrace Park at 1126 N. Hazard Ave. The Weingart East Los Angeles YMCA, 2900 Whittier Blvd., also opened as an emergency shelter and mask distribution site.

City News Service contributed to this report.