NOM-085-SEMARNAT (Mexican stationary-source air emissions standard)

NOM-085-SEMARNAT is a Mexican Official Standard (Norma Oficial Mexicana) on air pollution that sets the maximum permissible emission levels of indirect-heating combustion equipment. Its current version is NOM-085-SEMARNAT-2011, and it is one of the central instruments for controlling air emissions from industry, commerce and services in Mexico.

The standard was issued by the Ministry of the Environment and Natural Resources (SEMARNAT) and regulates equipment whose heat is transferred through combustion gases without those gases coming into direct contact with the process materials, such as boilers, steam generators, thermal-oil heaters, furnaces and indirect-heating dryers.

Which pollutants it regulates

NOM-085-SEMARNAT-2011 sets emission limits for the main pollutants associated with combustion:

• Smoke and particulate matter.
• Carbon monoxide (CO).
• Sulphur dioxide (SO2).
• Nitrogen oxides (NOx).

The permitted values vary according to the thermal capacity of the equipment, the type of fuel used (gas, liquid or solid) and the area of the country, with stricter requirements in critical or more densely populated zones. The standard also sets out the measurement methods to be followed to demonstrate compliance.

Who it applies to

The standard is mandatory for the individuals and companies responsible for stationary sources, of both federal and local jurisdiction, that operate indirect-heating combustion equipment. In other words, compliance can be verified by federal as well as state and municipal authorities, depending on the source.

Relationship with other environmental instruments

NOM-085 does not operate in isolation. For stationary sources under federal jurisdiction, its emission limits are built into the Single Environmental Licence (LAU), SEMARNAT's authorisation in atmospheric matters, and emission data are reported each year through the Annual Operating Report (COA), which feeds the Pollutant Release and Transfer Register (RETC). All of this sits within the General Law of Ecological Balance and Environmental Protection (LGEEPA). For new projects, air emissions are also usually assessed within the Environmental Impact Statement (MIA).

Why it matters for companies

For any company with indirect-heating boilers or furnaces, complying with NOM-085 is a basic condition of operation and a natural starting point for managing its environmental footprint. Measuring and reducing these emissions usually goes hand in hand with improving energy efficiency and advancing the decarbonisation of processes.

How Manglai can help

Manglai helps companies in Mexico measure and understand their environmental impact, integrating emissions control into a sustainability and decarbonisation strategy. Discover how Manglai can help you calculate your carbon footprint and build a rigorous reduction plan.