Guidance · Bay Area Air Quality Management District
BAAQMD Regulation 12, Rule 15: petroleum refining emissions tracking
Ambient air: refinery fenceline monitoring (Bay Area, California)
Bay Area Air Quality Management District Regulation 12, Rule 15 (Petroleum Refining Emissions Tracking, adopted 2016) requires Bay Area refineries to report annual emissions inventories and crude slate information, and to run real-time fenceline air monitoring with the data made public. It sets no concentration limit. Its Air Monitoring Guidelines require refineries to measure benzene, toluene, ethylbenzene, and xylenes (BTEX) and hydrogen sulfide at the fenceline, using open-path technology that measures in the parts-per-billion range. Refineries must also consider sulfur dioxide, alkanes or other organic compound indicators, 1,3-butadiene, and ammonia, and give a rationale for any compound they leave out.
Who it applies to
Who It Applies to
Petroleum refineries in the Bay Area Air Quality Management District, each under an Air Monitoring Plan the District approves. The rule has been amended since adoption, and a further amendment was under development in 2026.
Monitoring
How Monitoring Demonstrates Compliance
The guidelines ask for data at a five-minute time resolution, displayed to the public. Quality assurance is set in each refinery's plan and includes at least 75 % hourly data completeness for 90 % of the time, assessed quarterly. Because the rule sets no limit, what it asks of monitoring is coverage and continuity: the right compounds, a complete record, and siting that represents the fenceline and the community downwind.
Recommended
best match-
Thiamis connects 2 instruments
A gateway that connects the third-party instruments you choose to the Aethair Platform.
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Hydrogen Sulfide (H₂S)Ammonia (NH₃)Sulfur Dioxide (SO₂)RAE Systems (Honeywell) portable gas detectors.
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Defiant Technologies Specialty Air Analyzers
BTEX / speciated VOCDefiant Technologies FROG portable gas chromatograph (GC-PID).
Also measures 9 more
Methane (CH₄)Chlorine (Cl₂)Carbon Monoxide (CO)Carbon Dioxide (CO₂)Combustible (LEL)Nitric Oxide (NO)Nitrogen Dioxide (NO₂)Oxygen (O₂)VOC (Total) -
Recommended
best match-
Thiamis connects 3 instruments
A gateway that connects the third-party instruments you choose to the Aethair Platform.
-
Hydrogen Sulfide (H₂S)Ammonia (NH₃)Sulfur Dioxide (SO₂)
RAE Systems (Honeywell) portable gas detectors.
-
Wind DirectionWind SpeedR.M. Young ResponseONE weather instruments, with solid-state ultrasonic wind sensing and no moving parts.
Swap for
-
Defiant Technologies Specialty Air Analyzers
BTEX / speciated VOCDefiant Technologies FROG portable gas chromatograph (GC-PID).
Also measures 12 more
Methane (CH₄)Chlorine (Cl₂)Carbon Monoxide (CO)Carbon Dioxide (CO₂)Combustible (LEL)Nitric Oxide (NO)Nitrogen Dioxide (NO₂)Oxygen (O₂)VOC (Total)Relative HumidityBarometric PressureAir Temperature -
Who measures each parameter
| Parameter |  Aethair PRO |  Aethair IAQ | External |
|---|---|---|---|
| BTEX / speciated VOC | — | — | 1 instrument via Thiamis |
| Hydrogen Sulfide (H₂S) | H₂S cartridge | — | 4 instruments via Thiamis |
| Sulfur Dioxide (SO₂) | MultiSense, SO₂ cartridges | — | 1 instrument via Thiamis |
| Ammonia (NH₃) | — | — | 1 instrument via Thiamis |
Devices
Devices That Measure What BAAQMD 12-15 Relies On
How much of this standard one Aethair monitor covers, followed by the third-party instruments in the sensor catalog that measure its parameters. Each connects to Environet through a Thiamis gateway, which adds whatever the monitor leaves out.
Aethair monitors
Covers part of it (combine on one Thiamis)
Solutions
Solutions That Rely on BAAQMD 12-15
Oil & Gas / Petrochemical
Fence-line VOC, H₂S, and methane leak detection
Article Library
Articles on BAAQMD 12-15
Industrial Perimeter Air Quality Monitoring: Action Levels
What industrial perimeter monitoring requires at fenceline and construction sites: DER-10 CAMP action levels, EPA fenceline rules, and continuous records.
How to Choose an Air Quality Monitor: PRO, IAQ, or Thiamis
Compare Aethair PRO, IAQ, and Thiamis to match the right device to your site, from commercial interiors to industrial and fenceline monitoring.
Questions
BAAQMD 12-15 FAQ
Does BAAQMD Rule 12-15 set fenceline concentration limits?
No. It requires real-time fenceline monitoring and public data, not compliance with a concentration limit.
Which compounds must be monitored under Rule 12-15?
Benzene, toluene, ethylbenzene, xylenes, and hydrogen sulfide with open-path instruments measuring in the parts-per-billion range; sulfur dioxide, alkanes or other organic indicators, 1,3-butadiene, and ammonia are to be considered in each refinery's plan.
How often must Rule 12-15 fenceline data be collected?
The guidelines call for a time resolution of five minutes, with at least 75 % completeness on an hourly basis 90 % of the time, assessed by quarter.
Monitor What BAAQMD 12-15 Relies On
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