How we calculate our food waste figure (Tesco Lotus)

Scope and definitions 

The methodology outlined below is used to calculate the total tonnes of food wasted in our Thailand operations for the full Tesco financial year 2018/19. The information provided is in conformance with the Food Loss and Waste Accounting Standard (FLW Standard).[1]

Timeframe

The published figure represents the food wasted in our full financial year 2018/2019. This year, this includes 52 weeks, from 1st March 2018 to 28th February 2019 inclusive.

Store Location and Type              

The scope of this calculation covers food waste arising only from our depots and stores in Thailand. Food waste arising in our food courts and staff canteens in our stores and depots is out of scope, as is any food waste arising in operations owned by Tesco, upstream in the supply chain, such as haulage wastage and committed crop wastage.

The calculation only covers our operations. Therefore, waste arising at our suppliers’ sites and from third party counters in Tesco stores is not included.

Food Waste Definition

The food waste definition used by Tesco is aligned with that of the UK Food Waste Reduction Roadmap as well as that adopted by Champions 12.3.

Material types: The scope of the calculation includes food waste and associated inedible parts.

Destinations: The definition of food waste includes to following destinations (as defined in the FLW Standard): Anaerobic digestion/codigestion, Composting/aerobic processes, Incineration/controlled combustion, Land application, Landfill, Sewer/wastewater treatment, Not harvested/ploughed-in, Other (including unmanaged disposal).

Therefore, food donated to charities or sent to animal feed is not considered to be food waste.

Packaging waste is excluded.

Food Categories

All food categories sold at Tesco are included in the scope.[2]

During the calculations, all non-food items are removed from our waste data. The following products are out of scope and therefore excluded from the calculations:

  • All tobacco products
  • All pet care products
  • All products within Baby world department except baby food
  • Plants and flowers in the Produce category
  • Some individual products were excluded in other categories where they were clearly not food, for example: books, glassware

Data Sources 

In order to calculate the amount of food wasted each year we record the following data in our stores and depots.

Waste: This dataset contains the number of retail and depot units wasted and the total value (THB) of such waste per item. All reasons for waste are included in this dataset.

Product data: This dataset contains the contents weight per item. Note that where duplicates are found, a conservative estimate is taken and the highest weight is used.

Charity donations: Our charity partners provide weight data for donations from our stores and depots. Food donated to charities is scanned as waste in our stores and depots; therefore, the donated weight is subtracted from the total calculated surplus figure.

Methodology 

The bullet points below explain how we have calculated our total food waste tonnage for the full year 2018/19:

  • Included in the scope of our calculation is any food that has not been sold in our stores because it is past its best before or use by date, has been damaged, withdrawn from the market or de-ranged. The non-food categories mentioned above are removed at this stage.
  • The number of units wasted per item is converted into a weight measured in tonnes by multiplying the number of units wasted by the per unit weight*.
  • We perform a ‘bottom up’ calculation from the waste tonnages for individual products (e.g. Gala Apples), to the commercial food category (e.g. Produce), to our entire Thailand operations.
  • Waste tonnages are added to obtain totals by category and for our entire Thailand operations.
  • We used this calculation method for 90% of the waste products (by weight) from our own operations – in our depots and within our stores.
  • The remaining 10% of waste by weight (equivalent to 11% of total units wasted) occurs in products for which a weight is not available (this could include items such as baguettes in our bakery or food in our deli counters) or where the weight provided is not correct.
  • The following steps are taken to select the best estimate for product contents weights:
    1. Product content weights are checked category by category and are marked as requiring adjustment where the content weight is missing or if it is high or low compared to the category average.
    2. If an adjustment is required, items are checked on a sub-category basis and either the category or sub-category average is used based on expert judgement.
  • To minimise the risk associated with such estimates, categories with the largest number of waste items are prioritised and checked in more detail as these have the greatest impact on the total waste.
  • In addition, within each category, the products with the highest number of wasted units are checked manually one-by-one as these can also have a significant impact on the total waste tonnage. Items using self-scan weights are also checked to ensure that items with heavy packaging are not allocated these weights, for example wine bottles.
  • Finally, the tonnage of food donations is subtracted from the figure calculated as this is not food waste.

* It is assumed that 1 L is equivalent to 1 Kg where product content weights are listed as volumes.

Food waste intensity figures

In the annual report, we reported 0.52% of food was wasted in our Thailand operations. This figure represents our food waste per food sales by weight. The sales weight is measured using the same method for food waste: the number of units sold is multiplied by the same per unit weight used in the calculation described above.

[1] More information available here.

[2] United Nations Central Production Classifications 2.1 Divisions 21 – 24