Does white spirit or thinner that evaporates in my paint shop produce carbon dioxide, and what carbon share does the Intergovernmental Panel on Climate Change (IPCC) use?
Evaporated solvent is released as non-methane volatile organic compounds (NMVOC), not direct carbon dioxide (CO2), but it oxidises to CO2 in the air. The IPCC default fossil carbon fraction of NMVOC is 60 percent by mass, range 50 to 70, so 1 kilogram evaporated is about 2.2 kilograms of CO2.
What the Guidelines say
Volume 3 Chapter 5, Section 5.5: solvents made from fossil fuels, notably white spirit and kerosene, can lead to evaporative emissions of various NMVOC "which are subsequently further oxidised in the atmosphere". White spirit is named as the most widely used solvent in the paint industry. The CO2 that results is estimated from the NMVOC emitted. The default fossil carbon content of NMVOC is "60 percent by mass", which "may vary between 50 and 70 percent", with an uncertainty of about plus or minus 10 percent. The NMVOC emissions themselves are given an uncertainty of about plus or minus 50 percent.
The sum
CO2 = kilograms of solvent evaporated x carbon fraction x 44 / 12, where 44 / 12 is the mass ratio of CO2 to carbon, as in Equation 5.1. The 44 / 12 step is the standard conversion and is our application of it to this default. With 0.60: 0.60 x 44 / 12 = 2.2 kilograms of CO2 per kilogram.
Default or the solvent's own carbon
The 60 percent is an average across all NMVOC, not a figure for white spirit. Volume 2 gives white spirit a net calorific value of 40.2 gigajoules per tonne and a carbon content of 20.0 kilograms of carbon per gigajoule, which is 804 kilograms of carbon per tonne, or 80.4 percent. Our reading: if you use one known hydrocarbon thinner and evaporate all of it, the solvent's own carbon share is the closer match and is higher than the default. Pick one basis, state it, and keep it across years. Our volatile organic compounds page tells readers to use the solvent's own carbon fraction; this page shows the 60 percent IPCC default beside the white spirit figure so you can see the gap. Both are valid bases if stated.
What to subtract first
Take off what did not evaporate: spent thinner and sludge handed to a recycler or waste contractor, and thinner burnt on site, which is fuel combustion. What remains is the amount evaporated. Our diesel and kerosene cleaning page has the full tracking list.
Where it sits
The Guidelines describe the emission as NMVOC that is oxidised later in the atmosphere, not as fuel combustion. We suggest showing the CO2 as a memo line with its basis rather than inside your fuel total; our volatile organic compounds page explains why. The IPCC counts by sector and does not use Scopes.
A paint shop buying 2,000 kilograms of thinner in a year
- Recycler takes away 300 kilograms of spent thinner: evaporated = 2,000 minus 300 = 1,700 kilograms (assuming no stock change)
- IPCC default carbon fraction: 1,700 x 0.60 = 1,020 kilograms of carbon, and 1,020 x 44 / 12 = 3,740 kilograms of CO2, about 3.7 tonnes
- Solvent's own carbon share of 80.4 percent: 1,700 x 0.804 = 1,366.8 kilograms of carbon, and 1,366.8 x 44 / 12 = 5,011.6 kilograms of CO2, about 5.0 tonnes
- The second figure is 5,011.6 / 3,740 = 1.34 times the first
The 2,000 and 300 kilograms are examples. A thinner that is a blend with oxygen-containing solvents has a lower carbon share than a pure hydrocarbon; check the data sheet.
What Senseible does here
Senseible reads fuel invoices and electricity bills into dated records, so the gas or diesel for your booth heaters shows up once uploaded. It does not read thinner purchases or waste manifests, so keep that sheet yourself.
- Diesel or kerosene as a cleaning solvent
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- Free calculators
Sources: IPCC 2006 Guidelines, Volume 3 Chapter 5 (Section 5.5, Equation 5.1), IPCC 2006 Guidelines, Volume 2 Chapter 1 (Tables 1.2 and 1.3)
Last reviewed 2026-11-05. Defaults are from the 2006 Guidelines. If your buyer asks for a specific basis, follow theirs and say so.