Boyle Heights Response & Recovery

Air Monitoring Data

En Español  |  English

Boyle Heights Warehouse Fire Preliminary Air Monitoring Data: June 23 – July 13

Lineage is sharing this preliminary air monitoring data in connection with the Boyle Heights warehouse fire response, which is being collected by a third-party firm (Onterris) in coordination and with oversight by SCAQMD. The information below summarizes handheld real-time air monitoring readings collected between June 23 and July 13, 2026, and includes both a data table and live air quality monitoring map.

These materials are being provided to support transparency and help keep community members informed. The data are preliminary, have not undergone the full quality assurance and quality control process, and should be reviewed with that context in mind. Community members should continue to follow guidance from local public health agencies and emergency response officials.

July 13, 2026 Update:

Air monitoring did not identify chemical concentrations above health-based action levels. Deodorizing mists produced interferences with fine and coarse particulate matter readings during the recording period. Modifications to the mister system are being attempted to avoid these issues. Monitoring is continuing.

Air Monitoring Data Summary - July 13, 2026

Chemical Inspected Poses Health
Concern?a		 Highest Level
Observed		 Number of
Readings		 Screening Value
Carbon Monoxide (CO) No
Interferences
Observed		 1.1 ppm
(Average)		 13,544 9 ppm (NAAQS†)
Hydrogen Sulfide (H2S) No No Detection 3,462 0.51 ppm (EPA AEGL-1**)
Ammonia (NH3) No* 1 ppm
(Average)		 16,923 30 ppm (EPA AEGL-1**)
Chlorine No No Detection 164 0.5 ppm (EPA AEGL-1**)
Sulfur Dioxide (SO2) No No Detection 16 0.2 ppm (EPA AEGL-1**)
Volatile Organic Compounds (VOCs) No*
Peak value; not sustained		 0.7 ppm 14,587 0.5 ppm
(No official criteria†)
Fine Particulate Matter (PM2.5) No*
Interferences
Observed		 0.104 mg/m³
(Average)		 50,759 0.035 mg/m³
(Moderate AQI††)
Coarse Particulate Matter (PM10) No*
Interferences
Observed		 0.113 mg/m³
(Average)		 50,759 0.154 mg/m³
(Moderate AQI††)

Abbreviations: ppm = parts per million; mg/m³ = milligrams per cubic meter; AQI = air quality index; AEGL-1 = 1-hour Acute Exposure Guideline Levels; NAAQS = National Ambient Air Quality Standard

Note: This is a preliminary data summary, indicating that the data provided have not undergone the full quality assurance and quality control (QA/QC) process and should be considered preliminary at this time. Analytes with no detections are reported as less than (“<”) the instrument’s Limit of Detection (LOD). All O2 levels were similar to ambient conditions, and no detections were observed for atmospheric flammability as a percentage of the lower explosive limit.

*Reading was elevated but not sustained.

**United States Environmental Protection Agency (US EPA) Acute Exposure Guideline Levels AEGL-1 (AEGL-1; 1-hour) values represent the airborne concentration of a substance above which it is predicted that the general population, including susceptible individuals, could experience notable acute short-term discomfort, irritation, or certain asymptomatic, nonsensory effects. These effects are not disabling and are transient and reversible upon cessation of exposure.

†VOC concentrations sustained at 0.5 ppm is an action level for field teams. An exceedance in this value does not mean health effects will occur and is not a health-based guideline but is a threshold to promote further investigation in the community.

††Based on the US EPA National Ambient Air Quality Standard (NAAQS) criteria for pollutants and designed to protect public health with an adequate margin of safety.

aThe qualifier “No” means air monitoring did not indicate readings above health-based screening levels.

Air Quality Monitoring Map

Preliminary Air Monitoring Summary Reports

Looking for More Information?

Click below for community resources, frequently asked questions, progress updates and additional resources.

Learn More About Boyle Heights Response