How do I calculate the carbon footprint of a rotomoulded plastic water tank?

Multiply the LLDPE powder used per tank, including flash and rejects, by a resin factor. Add the rotomoulding oven's LPG, PNG or diesel, pulverising and cooling electricity, and fittings. Divide by tanks dispatched, and report each capacity separately since weight scales with litres.

Material

• LLDPE or MDPE powder: the largest share. A 1,000 litre tank uses many kilograms of polymer; weigh the charge per mould.
• UV stabiliser and carbon black or colour masterbatch.
• Brass or plastic fittings, lids and lids' threads.

Process energy

• Oven burners: LPG, PNG or diesel, usually the largest plant energy line.
• Pulveriser electricity if you grind your own powder from granules.
• Cooling fans and arm drives.

Per tank

Allocate oven fuel by cycle time or by charge weight per mould, since a 2,000 litre tank occupies the oven longer than a 500 litre one.

Worked example: tank plant per tank (one month)

• Oven LPG: 12,000 kg x 2.98 = 35,760 kg CO2
• Electricity: 20,000 kWh x 0.710 = 14,200 kg CO2
• Tanks made: 3,000
• Plant total: 49,960 / 3,000 = 16.65 kg CO2 per tank
• Add LLDPE powder and fittings for the full figure

Inputs are illustrative; use your own bills and production records.

What Senseible does here

Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.

• Product carbon footprint calculator
• Emission factors for PP, HDPE and PVC resin
• Recycled content in a product footprint

Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0

Last reviewed 2026-10-20.