Regulation
Vapour recovery: what NOM-004 requires in Tijuana and the Bajío
Gas stations in Celaya, Irapuato, Salamanca, Villagrán, Tijuana and Rosarito must test their vapour-recovery systems and file the report with ASEA in 2025 and 2026. What the standard requires, and in which months.
Every time a car is refuelled, the vapour that was in its tank is pushed into the air. Multiplied by thousands of refuellings a day, it becomes a significant source of volatile organic compounds, which contribute to ozone formation. That is why Mexico’s NOM-004-ASEA-2017 requires vapour-recovery systems at service stations in the zones with the worst air quality.
Where does it apply?
The standard applies to every station in nine zones across ten states, regardless of sales volume:
- Valley of Mexico metropolitan area (Mexico City and neighbouring municipalities of the State of Mexico)
- Monterrey and Guadalajara metropolitan areas
- Tampico, Altamira and Ciudad Madero; southern Veracruz (Coatzacoalcos, Minatitlán and neighbouring municipalities) and the Tula region (Hidalgo and State of Mexico)
- Guanajuato: Celaya, Irapuato, Salamanca and Villagrán
- Baja California: Tijuana and Playas de Rosarito
- Ciudad Juárez
In Guanajuato, León and Silao are not on the list; neither is Querétaro.
Stage I and Stage II
- Stage I: recovers vapour when the tanker truck unloads into the station’s tanks.
- Stage II: recovers vapour while dispensing to the vehicle, through nozzles and hoses that return the vapour to the storage tank.
The 2025–2026 calendar
On 27 January 2025, ASEA, Mexico’s safety and environment agency for the hydrocarbons sector, published in the Official Gazette a programme requiring stations in the listed zones to file a conformity assessment results report (initial test or current periodic test), signed by the operator and by an ASEA-approved testing laboratory. Filing is required in both 2025 and 2026, in windows by zone:
| Zone | Filing window |
|---|---|
| Valley of Mexico | April–May |
| Monterrey | June–July |
| Tamaulipas, Guanajuato and Tula | August–September |
| Southern Veracruz, Tijuana–Rosarito, Ciudad Juárez and Guadalajara | October–December |
For a station in Guanajuato’s industrial corridor, this year’s window is already open. Tijuana and Rosarito have until year-end, but demand for laboratories tends to bunch up at the close of each window: it pays to book the test now and fix any system fault beforehand.
What Germany does
Germany adopted Stage II vapour recovery with the 21st Federal Emission Control Ordinance (21. BImSchV) of 1992, applied from 1993. Since April 2003 it has required new stations to have an automatic monitoring system that continuously checks that recovery is working and raises an alarm when it fails; since 2019 systems must be certified with a minimum efficiency of 85 %. The difference is one of approach: Mexico tests the system periodically; Germany watches it every day.
More than an environmental obligation
Vapour recovery is also fuel that is not lost: vapour returned to the tank is product retained. In an environment where every litre is measured, reported and reconciled, reducing losses helps both environmental compliance and the volumetric-control balance.
Three practical steps:
- Confirm whether the station is in a covered zone and which window applies to its report.
- Check valves, nozzles and return lines before the test.
- Keep evidence of tests and maintenance with the rest of the station’s regulatory documentation.
This is an informational article, not legal or environmental advice. Each station’s obligations require specific review.
Sources: DOF — NOM-004-ASEA-2017 (14 Feb 2018) · DOF — 2025 and 2026 NOM-004-ASEA-2017 reporting programme (27 Jan 2025) · ASEA — register of approved third parties · 21. BImSchV (current text) · Umweltbundesamt — storage and transfer of fuels
This article is also available in Spanish. Read in Spanish