VOC
Volatile organic compounds: the part of a coating that leaves as vapor instead of staying on the floor, quoted as a weight per unit volume. It governs where a product may legally be used and whether a building can stay occupied, and it is routinely misread as a safety rating.
What the figure counts
VOC stands for volatile organic compounds, and on a coating the figure is the mass of volatile organic material in a given volume of product, normally written as grams per liter or pounds per gallon. Put plainly, it is how much of what you are buying is going to leave as vapor instead of staying on the floor.
That is why it moves in step with solids content. A product with a high solids figure has little in it that can evaporate, and a genuinely hundred percent solids one has essentially nothing. The two numbers are largely two views of the same fact, which is worth knowing because solids by volume is the figure that decides what a coating really covers. What does not stay on the floor has to go somewhere, and VOC is the accounting for where.
The misreading worth correcting
A low VOC product is not the same thing as a safe one, and treating the number as a safety rating is the most common error made with it.
VOC limits exist principally for air quality. Volatile organics react in sunlight to form ground level ozone, and regulators cap them for that reason rather than to protect the person holding the roller. The figure describes what the product does to the atmosphere, not what it does to you.
So a product can carry a low VOC figure and still be a skin sensitizer, still demand a respirator, and still be something nobody should be breathing in a closed room. The information about your own exposure sits in the hazard and protection sections of the safety data sheet, next to flash point, and reading a low number as permission to work unprotected is exactly the substitution this term invites.
Why the location matters as much as the product
VOC limits are regulatory and they are local. Jurisdictions set their own caps on what may be sold or applied within them, the caps vary by coating category as well as by region, and they are revised over time. A product that is entirely ordinary in one place can be unavailable or not permitted in another, and that is a question to settle before specifying rather than after.
Building owners then add their own conditions on top. A school, a hospital, a food production area or any space that cannot close will have a view about what can be used and when. In those buildings a low VOC or water based product is often what makes the work possible at all rather than simply preferable, and the specification follows the building rather than the floor.
Reading it without over-reading it
Water based usually means lower, but not always, and lower is not zero. Water based coatings commonly contain coalescing solvents that count toward the figure, so the sheet is worth checking rather than inferring from the carrier.
There is a trade to keep in view as well. The product records in our epoxy coverage calculator include a water based epoxy noted as low VOC and low odor and suitable for occupied areas, and the same record advises two coats for durability. That is the shape of the decision in miniature: choosing on VOC alone means accepting whatever the choice does to the build and the schedule, so it belongs alongside the other selection criteria rather than above them.
Both documents tend to carry the figure, which is unusual. The technical sheet often lists it among the product properties because it affects whether you can use the product at all, and the safety sheet covers it under regulatory information. Where they differ, or where one quotes the base and the other the mixed product, the mixed figure is the one describing what you will actually apply.
This page prints no limits, deliberately. Caps are jurisdictional, they differ by category, and they change. A number given here would be read as the rule in places where it is not, and that is a mistake with a regulator attached to it. Check the limit that applies where you are working, and the sheet for the product you intend to use.
Frequently Asked Questions
What does a VOC figure on a data sheet actually count?
The mass of volatile organic material in a given volume of the mixed product, usually written in grams per liter or pounds per gallon. It is a measure of how much of what you buy is going to end up in the air rather than on the slab.
That is why it tracks so closely with solids content. A high solids product has little to give off and a correspondingly low figure, and a genuinely hundred percent solids one has essentially nothing to give off at all. Solids and VOC are largely two views of the same fact about a product.
Does a low VOC product mean a safer product?
No, and this is the misreading worth correcting. VOC limits exist mainly for air quality reasons: volatile organics contribute to ground level ozone, and regulations cap them for that reason rather than to protect the person holding the roller.
A product can be low VOC and still require a respirator, still be a skin sensitizer, and still be something you would not want to breathe in an enclosed room. The figure that speaks to your exposure is on the safety data sheet, in the hazard and protection sections. Reading a low VOC number as permission to skip protection is the mistake this term invites.
Why does it matter where I am working?
Because VOC limits are regulatory and they are local. Jurisdictions set caps on what may be sold or applied within them, and the limits differ by coating category as well as by region, so a product that is ordinary in one place may not be permitted in another.
On top of that, building owners often set their own conditions. A school, a hospital, a food production area or any space that has to stay open will have opinions about what can be used and when, and a low VOC or water based product is frequently what makes the work possible at all rather than merely preferable.
Is a water based product always the low VOC option?
Usually lower, but do not assume it, and do not assume low means zero. Water based coatings still commonly contain coalescing solvents that count toward the figure, so the sheet is worth reading rather than inferring from the carrier.
It is also worth remembering the trade. Our coverage calculator carries a water based product noted as low VOC and low odor and suitable for occupied areas, and that same entry advises two coats for durability. Choosing on VOC alone means accepting whatever that choice does to the build, so it belongs alongside the other selection criteria rather than above them.
Where is the figure published?
Both sheets tend to carry it, which is unusual. The technical data sheet often lists it among the product properties because it affects whether you can use the product, and the safety data sheet covers it as part of the regulatory information.
If the two disagree, or if one gives a figure for the base and the other for the mixed product, the mixed figure is the one that describes what you will actually be applying.