Food waste

A bin containing biodegradable waste

Food waste or food loss is food that is discarded or cannot be used. The causes of food waste or loss are numerous, and occur at the stages of production, processing, retailing and consumption.

As of 2013, half of all food is wasted worldwide, according to the British Institution of Mechanical Engineers (IME).[1] Loss and wastage occurs at all stages of the food supply chain or value chain. In low-income countries, most loss occurs during production, while in developed countries much food – about 100 kilograms (220 lb) per person per year – is wasted at the consumption stage.[2]

Definition

The definition of waste is a contentious subject, often defined on a situational basis; this also applies to food waste.[3] Professional bodies, including international organizations, state governments and secretariats may use their own definitions.[4]

Definitions of food waste vary, among other things, in what food waste consists of,[5] how it is produced,[6] and where or what it is discarded from or generated by.[5] Definitions also vary because certain groups do not consider (or have traditionally not considered) food waste to be a waste material, due to its applications.[7][8] Some definitions of what food waste consists of are based on other waste definitions (e.g. agricultural waste) and which materials do not meet their definitions.[9]

United Nations

A 2011 study by the Swedish Institute for Food and Biotechnology (SIK) on behalf of Food and Agriculture Organization of the United Nations (FAO), Global Food Losses and Food Waste, distinguishes between "food loss" and "food waste", and provides figures for both:

European Union

In the European Union, food waste was defined as "any food substance, raw or cooked, which is discarded, or intended or required to be discarded" since 1975 until 2000 when the old directive was repealed by Directive 2008/98/EC, which has no specific definition of food waste.[11][12][12] The directive, 75/442/EEC, containing this definition was amended in 1991 (91/156) with the addition of "categories of waste" (Annex I) and the omission of any reference to national law.[13]

United States

The United States Environmental Protection Agency defines food waste for the United States as "uneaten food and food preparation wastes from residences and commercial establishments such as grocery stores, restaurants, and produce stands, institutional cafeterias and kitchens, and industrial sources like employee lunchrooms".[6] The states remain free to define food waste differently for their purposes,[7][14] though many choose not to.[9]

Causes

Production

In developing and developed countries which operate either commercial or industrial agriculture, food waste can occur at most stages of the food industry and in significant amounts.[15] In subsistence agriculture, the amounts of food waste are unknown, but are likely to be insignificant by comparison, due to the limited stages at which waste can occur, and given that food is grown for projected need as opposed to a global marketplace demand.[16][17] Nevertheless, on-farm losses in storage in developing countries, particularly in African countries, can be high although the exact nature of such losses is much debated.

Research into the food industry of the United States, whose food supply is the most diverse and abundant of any country in the world, found food waste occurring at the beginning of food production.[15] From planting, crops can be subjected to pest infestations and severe weather,[18][19] which cause losses before harvest.[15] Since natural forces (e.g. temperature and precipitation) remain the primary drivers of crop growth, losses from these can be experienced by all forms of outdoor agriculture.[20] The use of machinery in harvesting can cause waste, as harvesters may be unable to discern between ripe and immature crops, or collect only part of a crop.[15] Economic factors, such as regulations and standards for quality and appearance,[21] also cause food waste; farmers often harvest selectively, preferring to leave crops not to standard in the field (where they can be used as fertilizer or animal feed), since they would otherwise be discarded later.[15]

Food processing

Food waste continues in the post-harvest stage, but the amounts of post-harvest loss involved are relatively unknown and difficult to estimate.[22] Regardless, the variety of factors that contribute to food waste, both biological/environmental and socio-economical, would limit the usefulness and reliability of general figures.[22][23] In storage, considerable quantitative losses can be attributed to pests and micro-organisms.[24] This is a particular problem for countries that experience a combination of heat (around 30 °C) and ambient humidity (between 70 and 90 per cent), as such conditions encourage the reproduction of insect pests and micro-organisms.[25] Losses in the nutritional value, caloric value and edibility of crops, by extremes of temperature, humidity or the action of micro-organisms,[26] also account for food waste;[27][28] these "qualitative losses" are more difficult to assess than quantitative ones.[29] Further losses are generated in the handling of food and by shrinkage in weight or volume.[15][30]

Some of the food waste produced by processing can be difficult to reduce without affecting the quality of the finished product.[31] Food safety regulations are able to claim foods which contradict standards before they reach markets.[32] Although this can conflict with efforts to reuse food waste (such as in animal feed),[33] safety regulations are in place to ensure the health of the consumer; they are vitally important, especially in the processing of foodstuffs of animal origin (e.g. meat and dairy products), as contaminated products from these sources can lead to and are associated with microbiological and chemical hazards.[34][35]

Retail

Packaging protects food from damage during its transportation from farms and factories via warehouses to retailing, as well as preserving its freshness upon arrival.[36] Although it avoids considerable food waste,[36][37] packaging can compromise efforts to reduce food waste in other ways, such as by contaminating waste that could be used for animal feedstocks.[38]

Retail stores can throw away large quantities of food. Usually, this consists of items that have reached their either their best before, sell-by or use-by dates. Food that passed the best before, and sell-by date, and even some food that passed the use-by date is still edible at the time of disposal, but stores have widely varying policies to handle the excess food. Some stores put effort into preventing access to poor or homeless people, while others work with charitable organizations to distribute food. Retailers also contribute to waste as a result of their contractual arrangements with suppliers. Failure to supply agreed quantities renders farmers or processors liable to have their contracts cancelled. As a consequence, they plan to produce more than actually required to meet the contract, to have a margin of error. Surplus production is often simply disposed.[39]

Extent

Global extent

The 2011 SIK study estimated the total of global food loss and waste to around one third of the edible parts of food produced for human consumption, amounting to about 1.3 billion tons per year.[40] As the following table shows, industrialized and developing countries differ substantially. In the latter, more than 40% of losses occur at the postharvest and processing stages, while in the former, more than 40% of losses occur at the retail and consumer levels. The total food waste by consumers in industrialized countries (222 million tons) is almost equal to the entire food production in sub-Saharan Africa (230 million tons).[40]

Food loss and waste per person per year[41] Total At the production and retail stages By consumers
Europe 280 kg (620 lb) 190 kg (420 lb) 90 kg (200 lb)
North America and Oceania 295 kg (650 lb) 185 kg (408 lb) 110 kg (240 lb)
Industrialized Asia 240 kg (530 lb) 160 kg (350 lb) 80 kg (180 lb)
sub-Saharan Africa 160 kg (350 lb) 155 kg (342 lb) 5 kg (11 lb)
North Africa, West and Central Asia 215 kg (474 lb) 180 kg (400 lb) 35 kg (77 lb)
South and Southeast Asia 125 kg (276 lb) 110 kg (240 lb) 15 kg (33 lb)
Latin America 225 kg (496 lb) 200 kg (440 lb) 25 kg (55 lb)

A 2013 report of the British Institution of Mechanical Engineers (IME) likewise estimated that 30–50% (or 1.2–2 billion tonnes) of all food produced remains uneaten.[42]

Individual countries

New Zealand

United Kingdom

In the UK, 6.7 million tonnes per year of wasted food (purchased and edible food which is discarded) amounts to a cost of £10.2 billion each year. This represents costs of £250 to £400 a year per household.[43]

United States

A study by the University of Arizona in 2004 indicated that 14 to 15% of United States edible food is untouched or unopened, amounting to $43 billion worth of discarded, but edible, food.[44] Another survey, by the Cornell University Food and Brand Lab, found that 93 percent of respondents acknowledged buying foods they never used.[45]

Reduction and disposal

Response to the problem of food waste at all social levels has varied hugely, including campaigns from advisory and environmental groups,[46] and concentrated media attention on the subject.[43][47]

As alternatives to landfill, food waste can be composted to produce soil and fertilizer, fed to animals, or used to produce energy or fuel.


Limiting food wastage has seen the adoption of former World War I and World War II slogans by antiwaste groups such as WRAP.[43]

One way of dealing with food waste is to reduce its creation. Consumers can reduce spoilage by planning their food shopping, avoiding potentially wasteful spontaneous purchases, and storing foods properly.[46]

An initiative in Curitiba, Brazil called Cambio Verde allows farmers to provide surplus produce (produce they would otherwise discard due to too low prices) to people that bring glass and metal to recycling facilities (to encourage further waste reduction).[48]

Landfills and greenhouse gases

Dumping food waste in a landfill causes odour as it decomposes, attracts flies and vermin, and has the potential to add biological oxygen demand (BOD) to the leachate. The European Union Landfill Directive and Waste Regulations, like regulations in other countries, enjoin diverting organic wastes away from landfill disposal for these reasons. Starting in 2015, organic waste from New York City restaurants will be banned from landfills.[49]

In countries such as the United States and the United Kingdom, food scraps constitute around 19% of the waste dumped in landfills, where it ends up rotting and producing methane, a greenhouse gas.[45]

Municipal collection

In areas where waste collection is a public function, food waste is usually managed by the same governmental organization as other waste collection. Most food waste is combined with general waste at the source. Separate collections, also known as source-separated organics, have the advantage that food wastes can be disposed of in ways not applicable to other wastes. In the United States, companies find higher and better uses for large commercial generators of food and beverage waste.

From the end of the 19th century through the middle of the 20th century, many municipalities collected food waste (called "garbage" as opposed to "trash") separately. This was typically disinfected by steaming and fed to pigs, either on private farms or in municipal piggeries.[50]

Separate curbside collection of food waste is now being revived in some areas. To keep collection costs down and raise the rate of food waste segregation, some local authorities, especially in Europe, have introduced "alternate weekly collections" of biodegradable waste (including, e.g., garden waste), which enable a wider range of recyclable materials to be collected at reasonable cost, and improve their collection rates. However, they result in a two-week wait before the waste will be collected. The criticism is that particularly during hot weather, food waste rots and stinks, and attracts vermin. Waste container design is therefore essential to making such operations feasible.

Animal feed

The feeding of food scraps to animals is, historically, the most common way of dealing with household food waste.

It is now widely believed by scientists that the domestication of the dog was related to food scraps. Indeed, some believe that dogs "self-domesticated" by following around hunter-gatherer bands in order to eat their scraps. In many preindustrial societies, domestic dogs perform (or performed) valuable service to their human owners in exchange for scraps of meat. For example sled dogs in the Arctic, or herding dogs and livestock guardian dogs in Europe. Modern-day pet dogs are also often fed table scraps. In fact, taking leftovers home from a restaurant is often called a doggy bag.

One of the common animals to be fed household scraps is swine, in which case the food scraps are often called slop. See also: pig farming.

Chickens have traditionally been given mixtures of waste grains and milling by-products in a mixture called chicken scratch. As well, giving table scraps to backyard chickens is a large part of that movement's claim to sustainability[51] though not all backyard chicken growers recommend it[52]

Composting

Inevitable waste: peels of potato, onion, lemon, tangerine, banana, kiwi, egg

Food waste can be biodegraded by composting, and reused to fertilize soil.

Vermicomposting is the practise of feeding scraps to worms who produce fertilized soil as a byproduct.[53][54][55]

Food waste can be composted at home, avoiding central collection entirely, and many local authorities have schemes to provide subsidised composting bin systems. However, the proportion of the population willing to dispose of their food waste in that way may be limited.

Anaerobic digestion

Anaerobic digestion produces both useful gaseous products and a solid fibrous "compostable" material. Anaerobic digestion plants can provide energy from waste by burning the methane created from food and other organic wastes to generate electricity, defraying the plants' costs and reducing greenhouse gas emissions.

Food waste coming through the sanitary sewers from garbage disposal units is treated along with other sewage and contributes to sludge.

Commercial liquid food waste

Commercially, food waste in the form of wastewater coming from commercial kitchens’ sinks, dishwashers and floor drains is collected in holding tanks called grease interceptors to minimize flow to the sewer system. This often foul-smelling waste contains both organic and inorganic waste (chemical cleaners, etc.) and may also contain hazardous hydrogen sulfide gases. It is referred to as fats, oils, and grease (FOG) waste or more commonly “brown grease” (versus “yellow grease”, which is fryer oil that is easily collected and processed into biodiesel) and is an overwhelming problem, especially in the USA, for the aging sewer systems. Per the US EPA, sanitary sewer overflows also occur due to the improper discharge of FOGs to the collection system.[56] Overflows discharge 3 billion US gallons (11,000,000 m3) - 10 billion US gallons (38,000,000 m3) of untreated wastewater annually into local waterways, and up to 3,700 illnesses annually are due to exposure to contamination from sanitary sewer overflows into recreational waters.[57]

In US metropolitan areas, the brown grease is taken by pumpers or grease-hauling trucks to wastewater treatment plants, where they are charged to dump it. In other areas, it may be taken to a landfill or it may be illegally dumped somewhere unknown, to avoid charges. This unmonitored disposal process is not only harmful for our environment and our health, but it also hurts businesses which have no idea where their business waste ends up, or indeed how much liquid waste is in their grease interceptors at any point in time, leaving them vulnerable to illegal dumping into their own grease traps or interceptors. Some companies now market computerized monitoring services along with in situ bioremediation, which produces byproducts of CO2 and gray water that can safely flow into sewer systems. Other new technologies offer ex situ treatment to process brown grease into some form of transportation fuel. This may not be as environmentally friendly as in situ treatment, since it still requires vehicles to pump and transport the brown grease waste to the plants.

Estimating how much brown grease food waste is produced annually is difficult, but in the US alone, number is thought to be in the billions of gallons. In 2009, the city of San Francisco stated it produces about 10 million US gallons (38,000 m3) of brown grease a year. It is starting the first city-wide project in the US to recycle brown grease into biodiesel and other fuels.[58]

Dumpster diving

Further information: Dumpster diving

In regions where people practice dumpster diving, food waste is also reduced. However, it can pose a health risk to these people and there may also be questions of legality.

See also

References

References
  1. ↑ "Food Waste: Half Of All Food Ends Up Thrown Away". Huffington Post. 10 January 2013. Retrieved 5 February 2013.
  2. ↑ Gustavson et al., p. v.
  3. ↑ Westendorf 2000, pp. x-xi.
  4. ↑ Oreopoulou, p. 1.
  5. ↑ 5.0 5.1 "Glossary". Eastern Metropolitan Regional Council. Retrieved 2009-08-25.
  6. ↑ 6.0 6.1 "Terms of Environment: Glossary, Abbreviations and Acronyms (Glossary F)". United States Environmental Protection Agency. 2006. Retrieved 2009-08-20.
  7. ↑ 7.0 7.1 "Organic Materials Management Glossary". California Integrated Waste Management Board. 2008. Retrieved 2009-08-20.
  8. ↑ Oreopoulou, p. 2.
  9. ↑ 9.0 9.1 "Food Waste Composting Regulations" (PDF). California Integrated Waste Management Board. 2009. Retrieved 2013-11-14.
    "Many states surveyed for this paper do not define food waste or distinguish between pre-consumer and post consumer food waste, while other states classify food waste types."
  10. ↑ Gustavson et al., p. 2.
  11. ↑ "The Definition of Waste, Summary of European Court of Justice Judgments" (PDF). Defra. 2009. Retrieved 2009-08-20.
    "Whether it is waste must be determined ... by comparison with the definition set out in Article 1(a) of Directive 75/442, as amended by Directive 91/156, that is to say the discarding of the substance in question or the intention or requirement to discard it"
  12. ↑ 12.0 12.1 "Council Directive 75/442/EEC of 15 July 1975 on waste". EUR-Lex. 1975. Retrieved 2009-08-20.
    "For the purposes of this Directive: (a) "waste" means any substance or object which the holder disposes of or is required to dispose of pursuant to the provisions of national law in force;" (Amended by Directive 91/156)
  13. ↑ "Council Directive 91/156/EEC of 18 March 1991 amending Directive 75/442/EEC on waste". Eur-lex. 1991. Retrieved 2009-08-20.
  14. ↑ "Chapter 3.1. Compostable Materials Handling Operations and Facilities Regulatory Requirements". California Integrated Waste Management Board. Retrieved 2009-08-25.
    "Food Material" means any material that was acquired for animal or human consumption, is separated from the municipal solid waste stream, and that does not meet the definition of "agricultural material."
  15. ↑ 15.0 15.1 15.2 15.3 15.4 15.5 Kantor, p. 3.
  16. ↑ Waters, Tony (2007). The Persistence of Subsistence Agriculture: life beneath the level of the marketplace. Lexington Books. ISBN 978-0-7391-0768-3. Retrieved 2009-08-21.
  17. ↑ "Food Security". Scientific Alliance. 2009. Retrieved 2009-08-21.
    "… there is certainly a lot of waste in the system … Unless, that is, we were to go back to subsistence agriculture …"
  18. ↑ Savary, Serge; Laetitia Willocquet; Francisco A. Elazegui; Nancy P. Castilla; Paul S. Teng (March 2000). "Rice pest constraints in tropical Asia: Quantification of yield losses due to rice pests in a range of production situations". Plant Disease 84 (3): 357–369. doi:10.1094/PDIS.2000.84.3.357. Retrieved 2009-08-21.
  19. ↑ Rosenzweig, Cynthia; Ana Iglesias, X.B. Yang, Paul R. Epstein, and Eric Chivian (2001). "Climate change and extreme weather events, Implications for food production, plant diseases, and pests" (PDF). Global Change and Human Health 2. Retrieved 2009-08-21. (Free preview, full article available for purchase)
  20. ↑ Haile, Menghestab (29 November 2005). "Weather patterns, food security and humanitarian response in sub-Saharan Africa" (PDF). The Royal Society 360 (1463): 2169–82. doi:10.1098/rstb.2005.1746. PMC 1569582. PMID 16433102. Retrieved 2009-08-21.
    "… frequent extreme weather event such as droughts and floods that reduce agricultural outputs resulting in severe food shortages."
  21. ↑ "Wonky fruit & vegetables make a comeback!". European Parliament. 2009. Retrieved 2009-08-21.
  22. ↑ 22.0 22.1 Morris, p. 1.
  23. ↑ Morris, pp. 7–8
  24. ↑ Hall, p. 1.
  25. ↑ "Loss and waste: Do we really know what is involved?". Food and Agriculture Organization. Retrieved 2009-08-23.
  26. ↑ Lacey, J. (1989). "Pre- and post-harvest ecology of fungi causing spoilage of foods and other stored products". Journal of Applied Bacteriology Symposium Supplement. Retrieved 2009-08-22.
  27. ↑ Hall, p. 25.
  28. ↑ "Post-harvest system and food losses". Food and Agriculture Organization. Retrieved 2009-08-23.
  29. ↑ Kader, p. 1.
  30. ↑ Hall, p. 18.
  31. ↑ Oreopoulou, p. 3.
  32. ↑ Kantor, pp. 3–4.
  33. ↑ Dalzell, Janet M. (2000). Food industry and the environment in the European Union: practical issues and cost implications. Springer. p. 300. ISBN 0-8342-1719-8. Retrieved 2009-08-29.
  34. ↑ "Environmental, Health and Safety Guidelines for Meat Processing" (PDF). 2007. p. 2. Retrieved 2009-08-29.
  35. ↑ "Specific hygiene rules for food of animal origin". Europa. 2009. Retrieved 2009-08-29.
    "Foodstuffs of animal origin … may present microbiological and chemical hazards"
  36. ↑ 36.0 36.1 "Making the most of packaging, A strategy for a low-carbon economy" (PDF). Defra. 2009. Retrieved 2009-09-13.
  37. ↑ Robertson, Gordon L. (2006). Food packaging: principles and practice. CRC Press. ISBN 978-0-8493-3775-8. Retrieved 2009-09-27.
  38. ↑ "Review of Food Waste Depackaging Equipment" (PDF). Waste and Resources Action Programme (WRAP). 2009. Retrieved 2009-09-27.
  39. ↑
    • Stuart, Tristram (2009). Waste: Uncovering the Global Food Scandal: The True Cost of What the Global Food Industry Throws Away. Penguin. ISBN 0-14-103634-6.
  40. ↑ 40.0 40.1 Gustavson et al., p. 4
  41. ↑ Gustavsson et al., p. 5; visually estimated to within 5 kg from figure 2.
  42. ↑ Institution of Mechanical Engineers. "Global Food: Waste not, want not" (PDF). Retrieved 1 July 2014.
  43. ↑ 43.0 43.1 43.2 The Guardian - Call to use leftovers and cut food waste
  44. ↑ "US wastes half its food". Retrieved March 27, 2009.
  45. ↑ 45.0 45.1 From Farm to Fridge to Garbage Can. // The New York Times, 1.11.2010
  46. ↑ 46.0 46.1 Wrap - Household Food Waste
  47. ↑ The Independent
  48. ↑ Cambio verde project in Curitiba, Brazil
  49. ↑ Joel Rose (2014-03-11). "Turning Food Waste Into Fuel Takes Gumption And Trillions Of Bacteria". NPR.
  50. ↑ "Most of the smaller cities in this country dispose of a part or all their garbage by feeding to swine, but ... only four maintain municipal piggeries." Capes and Carpenter, 1918, p. 169
  51. ↑ "Feeding Your Chickens Table Scraps | McMurray Hatchery Blog". Blog.mcmurrayhatchery.com. 2011-10-04. Retrieved 2012-10-21.
  52. ↑ Chicken Feed: How to Feed Chickens. "Feeding Chickens: What to feed chickens to keep them healthy | Keeping Chickens: A Beginners Guide". Keeping Chickens. Retrieved 2012-10-21.
  53. ↑ Vermicomposting study for reducing food waste
  54. ↑ Vermicomposting for reducing food waste
  55. ↑ Vermicomposting for reducing food waste in restaurants
  56. ↑ EPA press release, June 19, 2008
  57. ↑
  58. ↑ San Francisco Chronicle, February 5, 2009
Bibliography

Further reading

External links

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