How much of the hydrofluorocarbon (HFC) cleaning solvent we buy does the Intergovernmental Panel on Climate Change (IPCC) count as emitted in the year we buy it?
The IPCC default is 50 percent of the solvent sold in the year of purchase and the rest the next year, less solvent destroyed in the previous year. For new equipment the Guidelines say approximately 10 to 20 percent may be emitted on first fill; later purchases are replenishment that can eventually be considered 100 percent emitted.
The equation
Volume 3 Chapter 7, Equation 7.5: Emissions in year t = S(t) x EF + S(t-1) x (1 minus EF) minus D(t-1), where S is the tonnes of solvent sold, EF is the fraction emitted in the year of first use and D(t-1) is the solvent destroyed in the previous year. The default EF is 50 percent of the initial charge a year. The Guidelines assume a product life of two years, so anything not emitted in the first year is emitted in the second.
New machines and top-ups
A footnote gives guidance for equipment: "for sales to new equipment, approximately 10-20 percent may be emitted with the rest of the solvent used to fill the equipment. In subsequent years sales are for replenishment and can eventually be considered 100 percent emitted." The Guidelines add that low-emission designs, good work practice and operator training lower losses, and that recovery and recycling are "in general" reflected in smaller purchases of new solvent.
Which solvents and what is left out
- HFC and perfluorocarbon (PFC) solvents only. The Guidelines name HFC-43-10mee as the most common, with HFC-365mfc and heptafluorocyclopentane also used. Other solvent families are not in this method.
- Solvent delivered from aerosol cans is counted under aerosols, not here.
- Electronics manufacturing is covered separately in Chapter 6, and the Guidelines say to avoid double counting between the two.
Our reading for one site
Equation 7.5 is written for a country's sales. A single plant can use its own purchase records for S, and its spent-solvent manifests for D. Keep the destruction paperwork: only solvent sent to destruction can be subtracted.
Purchases of a cleaning solvent over two years
- Year t-1: 100 kilograms bought, of which 10 kilograms were sent for destruction
- Year t: 80 kilograms bought
- Emissions in year t = 80 x 0.5 + 100 x (1 minus 0.5) minus 10 = 40 + 50 minus 10 = 80 kilograms
- Multiply by the global warming potential of the solvent in your chosen report to reach carbon dioxide equivalent (CO2e)
The quantities are examples. Use your purchase invoices and destruction manifests.
What Senseible does here
Senseible reads fuel invoices and electricity bills into dated records. It does not read solvent purchases or destruction manifests, so keep that sheet yourself and add the kilograms to your inventory.
Sources: IPCC 2006 Guidelines, Volume 3 Chapter 7 (Section 7.2, Equation 7.5 and footnote 10)
Last reviewed 2026-11-05. Equation 7.5 is a national sales model; the single-site use is our reading.