South Africa has lost R71.4 billion to inedible food waste in 2013, the CSIR estimates. A CSIR-developed equation that takes into account the costs of inedible food waste disposed in landfills is used to derive the unit cost per tonne of the inedible food waste.

The economic, social and environmental costs of food waste are being increasingly recognised. Food waste consists of both edible and inedible components. Whilst wastage of edible food is problematic for obvious reasons, there are also costs associated with the disposal of the inedible fraction to landfill.

The total opportunity cost of inedible food waste in South Africa can be estimated by multiplying  the quantity of edible food waste generated, which is 2.4 million tonnes per year by the weighted average unit cost per tonne of R2 668 per year, giving rise to a cost of R6.4 billion per annum. This can be added to the cost per tonne of edible food waste generated through the value chain of R65 billion when using 2013 prices, it gives rise to a total cost of R71.4 billion per annum. The weighted average opportunity cost is R5 667 per tonne food waste in South Africa. The food waste for edible and inedible food generated is 12.6 million tonnes per year.

The estimates are based on opportunity costs which refer to the value that could have been acquired had the food been used for bio-energy generation, composting and production of animal feed. The CSIR-developed equation will help municipalities, government officials and private businesses have a complete assessment of the total cost of food waste in South Africa.

The costs should be compared to the rates for substitutes to landfilling in order to make informed decisions regarding waste management alternatives.