For the purposes of this Regulation, the following definitions apply:
3.1 Ambient air: Atmosphere in an open space.
3.2 Zero air: Air subjected to a purification process by artificial methods.
3.3 Atmosphere: The total mass of gases surrounding the earth, composed mainly of oxygen and nitrogen.
3.4 Calibration: Adjustment of an instrument by checking its accuracy against a standard.
3.5 Air quality: The sum of the interrelated characteristics of the state of the outdoor air. It is normally qualified as good or bad, according to the established pollution index.
3.6 Standard gas cylinder: The container whose content has been measured and certified by the competent authority.
3.7 Concentration of pollutants: The ratio of the quantity of pollutants to the total quantity of gas considered. The units in which the quantity of the pollutant and the gas are expressed must be indicated.
3.8 Reference conditions: The temperature and barometric pressure to which the results of sampling and analysis of a pollutant in the air must be corrected. These conditions are: temperature 298 K (25°C) and barometric pressure 101 kPa (760 mm Hg).
3.9 Atmospheric pollution: For legal and regulatory purposes, the deterioration of the purity of the atmosphere by the presence of polluting agents, such as solid particles, dust, smoke, vapor, gases, radioactive materials, and others, as defined by the Ministry, in concentrations exceeding those permitted by air purity standards accepted internationally and officially declared by the Ministry.
3.10 Pollutant: Any matter or energy in any of its physical states and forms that, when incorporated into or acting upon the atmosphere, water, soil, flora, fauna, or any environmental element, alters or modifies its natural composition and degrades its quality.
3.11 Criteria pollutant: Those regulated pollutants for which a maximum concentration limit in ambient air has been established, with the purpose of protecting human health and ensuring the well-being of the population. These are: ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead, total suspended particles, suspended particles less than 10 micrometers, and suspended particles less than 2.5 micrometers.
3.12 Secondary pollutant: A pollutant that can be produced in the atmosphere by physical or chemical processes from pollutants or other substances present as a result of emissions from stationary or mobile sources.
3.13 Sulfur dioxide: Colorless gas with a pungent odor that, upon oxidizing and combining with water, forms sulfuric acid, the main component of acid rain. It irritates the eyes and the respiratory tract. It reduces lung functions and aggravates respiratory diseases such as asthma, chronic bronchitis, and emphysema.
3.14 Nitrogen dioxide: Reddish-brown gas with a pungent odor that, upon oxidizing and undergoing photochemical reactions, combines with water and forms nitric acid and other compounds. It irritates the lungs, aggravates respiratory and cardiovascular diseases.
3.15 Calibration equipment: The device or set of devices that allow establishing the reference standard against which the operation of the measurement equipment will be compared.
3.16 Measurement equipment: The set of instrumental devices necessary to measure the concentration of a pollutant.
3.17 Monitoring station: The set of technical elements designed to measure the concentration of pollutants in the air simultaneously, in order to evaluate air quality in a specific area.
3.18 Primary standard: Value designed to guarantee the protection of public health, including children and sensitive groups.
3.19 Secondary standard: Value designed to guarantee protection against reduced visibility and damage to animals, crops, vegetation, and infrastructure.
3.20 Air pollution index: A mathematical combination of the concentration of air pollutants that yields a single number, with the purpose of describing the quality of ambient air.
3.21 Immission: The transfer of pollutants from the atmosphere to a receptor.
3.22 Heavy Metals: Chemical elements of very high density; they are pollutants and can be dangerous to human health and the environment as they are bioaccumulative.
They are present in human nutrition, in the air breathed, and in various vital aspects. Among these are aluminum, arsenic, lead, cobalt, mercury, beryllium, selenium, cadmium, antimony, chromium, copper, tin, nickel, iron, zinc, vanadium, tungsten, and manganese. For their measurement in ambient air, these are sampled and analyzed from the PM10 particulate material fraction.
3.23 Reference Method: The analysis and measurement procedure described in this regulation, which must be applied to determine the concentration of a pollutant in ambient air and which also serves, where appropriate, to contrast the equivalent method, when this has been established by the Ministry of Health.
3.24 Equivalent method: The analysis and measurement procedure for determining the concentration of a pollutant in ambient air, designated as such by the Ministry of Health, based on this regulation, for producing results similar to those obtained with the reference method and which can be applied in substitution thereof.
3.25 Monitoring: Repeated sampling and measurements to determine changes in pollutant levels or concentrations over a determined period and at a determined site. In a restricted sense, it is the regular sampling or measurement of pollution levels in relation to a standard, or to judge the effectiveness of a control system.
3.26 Carbon monoxide: A colorless and odorless gas, a product of incomplete combustion, which combines with hemoglobin to form carboxyhemoglobin and can reach lethal concentrations. Carboxyhemoglobin affects the central nervous system, causing functional, cardiac, and pulmonary changes, headache, fatigue, drowsiness, respiratory failures, and even death.
3.27 Ozone: The allotropic form of oxygen, colorless and gaseous, which is produced in the presence of sunlight, hydrocarbons, oxygen, and nitrogen dioxide. It oxidizes materials not immediately oxidizable by gaseous oxygen. It irritates the eyes and respiratory tract. It aggravates respiratory and cardiovascular diseases.
3.28 Particles: Any material existing in a solid or liquid state in the atmosphere or in a gas stream under normal conditions.
3.29 Total Suspended Particles (TSP): Divided solids and liquids that can be dispersed in the air, originating from combustion processes, industrial activities, or natural sources, and whose aerodynamic diameter is less than 60 micrometers.
3.30 Lead: A heavy metal that occurs in the form of dust, aerosol, or vapor. It accumulates in the body's organs, causes anemia, kidney damage, and damage to the central nervous system (saturnism).
3.31 PM10: Solid or liquid particles dispersed in the atmosphere whose diameter is less than or equal to 10 micrometers. They are known as respirable particles because they have the particularity of penetrating the respiratory system up to the pulmonary alveoli. Their origin can be dust, ashes, soot, metallic particles, cement, or pollen.
3.32 PM2.5: Solid or liquid particles dispersed in the atmosphere whose diameter is less than or equal to 2.5 micrometers.