How do I calculate the carbon footprint of IQF frozen vegetables per kg?
Per kg of packed frozen product, add the raw vegetables bought (including trimming and blanching loss) times a farm factor, blanching steam fuel, electricity for the IQF tunnel and cold store, refrigerant topped up times its GWP, and packaging. Freezing and storage power is often the largest plant line.
Raw material yield comes first
Divide kg of raw vegetables received by kg of frozen product packed in the same period. Peeling, trimming, sorting rejects and blanching losses all sit in that ratio, so the ratio is always above 1. Multiply by a farm factor from your growers' data or a cited dataset.
The freezing and storage lines
- IQF tunnel, compressors and condensers: usually the largest electricity user. Sub-meter it if you can.
- Cold store: power for product waiting to ship. Long storage raises the figure, so state the average days held.
- Blanching: boiler fuel for steam or hot water, from fuel invoices.
- DG sets during power cuts: diesel litres x 2.68 kg CO2.
Refrigerant leaks
Kilograms of refrigerant topped up in the year are a fair measure of kilograms leaked. Multiply by the gas's GWP and name the IPCC report you used. An ammonia plant adds almost nothing here; an R-404A or R-134a plant can add a visible share. Without top-up records, IPCC 2006 Vol. 3 Ch. 7 gives annual leak rates by equipment type, labelled an estimate.
Where the boundary stops
A cradle to gate figure stops when the cartons leave your cold store. Reefer trucks, the reefer container and the importer's cold store are later stages the buyer adds, or you add only if they ask for delivered product.
Worked example: one month, 400 t of frozen peas (illustrative inputs)
- Raw peas: 520,000 kg x 0.15 kg CO2e per kg (assumed farm factor) = 78,000 kg CO2e
- Blanching furnace oil: 12,000 L x 2.97 = 35,640 kg CO2
- Electricity, processing, IQF and cold store: 400,000 kWh x 0.710 = 284,000 kg CO2
- DG diesel: 4,000 L x 2.68 = 10,720 kg CO2
- R-134a top-ups: 30 kg x 1,530 (IPCC AR6 GWP) = 45,900 kg CO2e
- Packaging: LDPE 8,000 kg x 2.5 = 20,000; cartons 16,000 kg x 1.0 = 16,000 kg CO2e (assumed factors)
- Total: 78,000 + 35,640 + 284,000 + 10,720 + 45,900 + 20,000 + 16,000 = 490,260 kg
- Per kg packed: 490,260 / 400,000 = 1.23 kg CO2e
Farm and packaging factors are assumptions. Electricity is 58% of this total.
What Senseible does here
Senseible reads electricity bills (billing period, tariff, sanctioned load and units, at 0.710 kg CO2 per kWh, CEA version 21.0) and fuel invoices such as furnace oil and diesel (IPCC 2006 defaults) into Scope 1 and 2 with the factor on each line. Refrigerant is calculated when you give the gas and kilograms charged; raw material and output come from your records.
- Processed food footprint per kg
- Cold storage emissions per tonne
- Refrigerant top-up invoice to CO2e
- Reefer container emissions
Sources: GHG Protocol Product Life Cycle Accounting and Reporting Standard (2011), 2006 IPCC Guidelines, Vol. 3, Ch. 7, refrigeration and air conditioning emission rates, IPCC AR6 WG1, Chapter 7, GWP100 values
Last reviewed 2026-10-19.