Levels and recommendations
Temperature
The range of temperatures at which a state of comfort is obtained goes from 21 to 25ºC, being, according to the RITE (Thermal Installations Regulation), 21-23ºC in winter and 23-25ºC in summer, although these values can be increased and/or decreased depending on the rest of the variables that condition comfort.
My inBiot Ranks:
MICA only establishes a range of risk values for indoor temperature in the case of indoor air quality assessment projects, since they must be evaluated together with other parameters such as relative humidity, mainly due to the variability of the factors that determine comfort. These comfort values are in the range of 19 - 27ºC.
Humidity
The ideal relative humidity for a normal indoor temperature in a living space is between 45 and 50% humidity, with a range of recommended values between 40 and 60%. My inBiot ranges:
- GREEN: 35 - 60 %.
- YELLOW: 25 - 35% / 60 - 70%.
- ROJO: < 25 % o > 70%
Read more about Relative Humidity
Carbon dioxide (CO2)
In outdoor environments the CO2 concentration level is approximately 350 - 400 ppm (parts per million). The environment is considered "charged" at values above 800 - 1,000 ppm. Above 2,000 ppm it is considered highly charged and symptoms related to headache, fatigue and general apathy occur. The most serious effects occur at 5,000 ppm and above, when fainting may occur.
My inBiot Ranks:
- VERDE: < 800 ppm
- YELLOW: 800 - 1,500 ppm
- RED: > 1,500 ppm
Formaldehyde
The limits established in Spain for short-term occupational exposures (VLA-EC) are 0.3 ppm or 370 μg/m³. However, there is no reference value for indoor residential use.
The technical standard for measurement in Bioconstruction SBM2015 includes the following indicative values for formaldehyde concentration in indoor air for rest areas:
- No significativo: < 20 μg/m³
- Weakly significant: 20 - 50 μg/m³
- Strongly significant: 50 - 100 μg/m³
- Extremely significant: > 100 μg/m³
The ranges of values used in the device MICA as indicators are collected taking into account the SBM values for resting areas, as well as the values above which allergic and sensitizing reactions occur.
My inBiot Ranks:
- VERDE: < 70 μg/m³
- YELLOW: 70 - 120 μg/m³
- RED: > 120 μg/m³
Volatile organic compounds (TVOC)
The AGÖEF (German Association for Ecological Research) has been working since 1993 to develop reference values for chemical compounds in both air and dust samples.
The recommended limits are:
- Percentil 50 (valor normal): No es considerada suficiente evidencia para acción urgente - TVOC < 360 μg/m³
- Percentil 90 (valor de atención): Fuente emisora presente - TVOC < 1.572 μg/m³
- Guidance values: Reference value equivalent to derived toxicological risk values - TVOC = 1,000 μg/m³.
The indicative values in the SBM2015 measurement standard refer to total volatile organic compounds, which are recommended as precautionary values for rest areas:
- No significativo: <100 μg/m³
- Weakly significant: 100 - 300 μg/m³
- Strongly significant: 300 - 1000 μg/m³
- Extremely significant: >1000 μg/m³
The ranges of values used in the device MICA as indicators are collected taking into account the values of the German Federal Environmental Agency, above which, depending on the exposure time, may lead to allergic and sensitizing reactions, hypersensitivities or diseases of various pathologies.
My inBiot Ranks:
- VERDE: < 204 ppb
- YELLOW: 204 - 621 ppb
- RED: > 621 ppb
Particulate matter (PM1.0, PM2.5 & PM4.0)
PM2.5 particles (with diameter ≤ 2.5 μm) can remain in the air for weeks and are more susceptible to travel through ventilation systems.
The current EPA (United States Environmental Protection Agency) standards recommend maximum values for PM2.5 of 35 μg/m³, although it reduces the total annual values to 12 - 15 μg/m³. The EU sets maximum levels of 20 μg/m³ also for PM2.5 although with the prospect of increasing the restriction.
My inBiot Ranks:
- VERDE: < 15 μg/m³
- AMARILLO: < 35 μg/m³
- RED: PM2.5 >= 35 μg/m³
Particulate matter (PM10)
Particles larger than 10 μm settle quickly in dust; PM10 particles (with diameter ≤ 10 μm) can remain suspended for hours.
My inBiot Ranks:
- VERDE: < 50 μg/m³
- YELLOW: 50 - 100 μg/m³
- RED: > 100 μg/m³
Read more about particulate matter
Ozone (O3)
The importance of ozone as an air pollutant has been recognized since the middle of the 20th century. The WHO establishes a maximum daily exposure limit of 50 ppb considering an 8-hour working day. As for the European directive and the Spanish legislation, they refer only to outdoor air quality and determine an exposure limit of 60 ppb, also for an 8-hour average. The daily environmental exposure limit value (ELV-ED) sets these thresholds, which depend on the work performed during a 40-hour working week: 50 ppb for heavy work, 80 ppb for moderate work and 100 ppb for light work.
The ranges of values used as indicators are based on the values recommended by the WHO and European bodies, and on the levels above which adverse health effects occur.
My inBiot Ranks:
- VERDE: < 51 ppb
- YELLOW: 51 - 122 ppb
- RED: > 122 ppb
Nitrogen dioxide (NO2)
The limits established in Spain for short-term exposures (VLA-EC), referring to averages of 15-minute periods, are 5 ppm. The limits for daily exposure (VLAED) for a standard 8-hour working day are 3 ppm. On the other hand, the hourly limit value for the protection of human health is more restrictive and is set at 105 ppb, while the annual limit value is 21 ppb. The WHO, on the other hand, establishes a limit of 5 ppb for average annual exposure, and 13 ppb for average daily exposure.
On the other hand, the EPA sets an annual level of 53 ppb for health protection. These are all outdoor exposure limits, as there are no normative reference values for indoor spaces, beyond WHO recommendations or private standards such as the WELL certification.
My inBiot Ranks:
- VERDE: < 21 ppb
- YELLOW: 21 - 105 ppb
- RED: > 105 ppb
Read more about nitrogen dioxide
Carbon Monoxide (CO)
The WHO establishes recommended concentration limits in outdoor areas. A limit of 25 ppm is determined for exposures in one hour, and 9 ppm for exposures in an 8-hour working day. The daily environmental exposure limit value (ELV-ED) establishes a maximum of 25 ppm in Spain. The limit value for human health protection is also 9 ppm for an 8-hour working day. With respect to indoor exposure limits, LEED certification establishes a limit of 9 ppm in a pre-occupancy air test of new construction.
My inBiot Ranks:
- VERDE: < 9 ppm
- YELLOW: 9 - 25 ppm
- RED: > 25 ppm