Volatile Organic Compounds - TVOC

August 2021

1. Description

Volatile organic compounds- VOCs - or TVOC, are all those hydrocarbons present in a gaseous state at normal ambient temperature, or which are very volatile at that temperature. An organic compound that at 20°C has a vapor pressure of 0.01 kPa or more, or an equivalent volatility under the particular conditions of use - and a boiling point between 50 and 260°C - can be considered as a VOC.

VOCs are frequently released from solvents, paints and other products commonly used in buildings. TCOVs are total organic compounds, the sum of all VOCs measured in indoor air.

2. Recommended levels

There are more than 120,000 chemical substances and more than 12 million published compounds. Of these, only a small part is studied from a medical perspective and there are only limit values for about 500 in the occupational/professional field alone. In the area of housing, there is no specific regulation in the field of VOC pollution - beyond recommendations.
For an overall assessment of total organic compounds, the total air concentration in ppb (parts per billion) or µg/m³ of a ratio of alcohols, aldehydes, ketones, amines, siloxanes, aromatic and aliphatic hydrocarbons is measured. Other compounds with a more critical health response, such as benzene, naphthalenes, cresols, or styrene, need to be studied on a case-by-case basis.

According to standards:
The AGÖEF is the German Association for Ecological Research; an association of independent consulting and service companies involved in the measurement of indoor air pollution in built environments. Since 1993 they have been working on the development of reference values for chemical compounds, both in air and in dust samples, which are valid references for the work developed in this report.
The recommendation limits are classified as follows:

  • P50 - 50th percentile. Normal value. Not considered sufficient evidence for urgent action - TVOC < 360 µg/m³.
  • P90 - 90th percentile. Attention value. Emitting source present - TVOC < 1572 µg/m³.
  • Guidance values - Guidance values - Equivalent to derived toxicological risk values - TVOC = 1000 µg/m³

The indicative values in the measurement standard SBM2015 refer to total volatile organic compounds, which are recommended as precautionary values for rest areas:

  • Not significant : < 100 µg/m³
  • Slightly significant : 100 - 300 µg/m³
  • Strongly significant : 300 - 1000 µg/m³
  • Extremely Significant : >1000 µg/m³

The limits established in Spain for exposures are listed according to individual compounds in the Occupational Exposure Limits for Chemical Agents in Spain, updated every year.
There is no reference value for indoor exposure in dwellings, nor for total organic compounds.

3. My inBiot Ranks

The reference values in My inbiot are based on the classification of total volatile organic compounds of the German Federal Environmental Agency, above which, depending on the exposure time, they can lead to allergic and sensitizing reactions, hypersensitivities or diseases of various pathologies.

Based on these values, the following ranges have been established in My inbiot:

  • GREEN < 220 ppb
  • YELLOW 220 - 660 ppb
  • RED > 660 ppb

4. Unit of measurement

The concentration of total organic compounds in air is determined in ppb (parts per billion).
The relationship between ppb and µg/m³ is not straightforward, as the TVOC ratio is the sum of a number of compounds with different behaviour and molecular weights. The TVOC value is calculated as the sum of all detected compounds from the equivalent value of toluene for each of them, according to UNE 16516.

5. Sources

Volatile organic compounds are present in solvents, paints, glues, varnishes and the like, in plastics, furniture, building materials (insulation, finishing boards, foams), cleaning, hygiene and maintenance products in buildings. They are common compounds, easily found in building interiors.

6. Benefits of optimal levels  

We spend 80-90% of our time indoors. Our interrelationship with factors such as temperature, humidity, air renewal or the presence of volatile organic compounds characterise a suitable indoor environment and condition our health.
An indoor environment without the presence of harmful volatile organic compounds will be an indoor environment focused on health, without the presence of irritating and/or potentially allergic substances, guaranteeing comfort and well-being, with positive impacts on the productivity and creativity of its occupants.

7. Risks of inadequate levels

The risk from the presence of VOCs occurs mainly during application and the first days and weeks immediately after application. Although some substitute compounds for the most prevalent VOCs with the highest health impact are being replaced by alternatives with higher boiling points, and which can therefore off-gas for longer periods of time, with a consequent health risk.
The health effects are diverse, depending on the compound and the period of exposure. They are generally fat-soluble and in the short term may result in allergic reactions, headache, mucosal irritation, itchy nose, red eyes, coughing, fatigue, dizziness or skin spots. In the long term, they may damage the liver, kidneys or central nervous system, and some of them may be carcinogenic.

8. Recommendations for improvement

  • Adequate air renewal.
  • Elimination of the polluting source.
  • Use of certified low VOC-emitting construction and finishing products (EC1 plus).
  • Review of hygiene and cleaning products.

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