Glow C's TVOC sensor measures total VOC levels rather than individual chemicals. There are several reasons why VOCs are measured collectively rather than individually:
The EPA’s Technical Assistance Document for Sampling and Analysis of Ozone Precursors lists more than 90 target VOCs that have potentially negative health effects. Their Substance Registry Service lists over 230 potential VOCs. To measure each VOC individually, you’d need an individual sensor for each.
VOCs tend to co-occur. In other words, if a few of the VOCs in the above lists are present (related to a specific source), others are likely to be as well. Ventilation or removal of the chemical pollution source will generally help reduce all VOCs that are present.
VOCs have a cumulative effect on health and comfort. In other words, the more VOCs that are present, the greater the risk to your health. For example, numerous VOCs are asphyxiants. Asphyxiants displace oxygen in the blood. If a person breathes in multiple asphyxiants, each one is working to displace oxygen in the blood and the effects will be compounded.
Because VOCs occur as a group, measuring and reporting each chemical individually is impractical. Measuring them as a group is simpler and far more effective.
Another way to look at VOCs is by category, as shown below.
Some example chemicals (although not exhaustive):
- Acetic Acid
- m- & p-Xylenes
- Carbon monoxide
- Ethyl acetate
- Butyl acetate
- Texanol 1&3
- Methylene chloride
- t-Butyl methyl ether
- Carbon tetrachloride
- Carbon disulfide
- + additional chemicals comprised of H, C, and O