Food waste

A bin containing biodegradable waste

Food waste or food loss is food that is discarded or lost or uneaten. The causes of food waste or loss are numerous, and occur at the stages of production, processing, retailing and consumption.^[1]

As of 2013, half of all food is wasted worldwide, according to the British Institution of Mechanical Engineers (IME).^[2] 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.^[3]

Definition

The definition of waste is a contentious subject, often defined on a situational basis; this also applies to food waste.^[4] Professional bodies, including international organizations, state governments and secretariats may use their own definitions.^[5]

Definitions of food waste vary, among other things, in what food waste consists of,^[6] how it is produced,^[7] and where or what it is discarded from or generated by.^[6] 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.^[8][9] 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.^[10]

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:

• Food loss measures the decrease in edible food mass (excluding inedible parts and seed) "throughout the part of the supply chain that specifically leads to edible food for human consumption", that is, loss at the production, postharvest and processing stages. This definition of loss includes biomass originally meant for human consumption but eventually used for some other purpose, such as fuel or animal feed.
• Food waste is food loss occurring during the retail and final consumption stages due to the behavior of retailers and consumers^[11] – that is, the throwing away of food.

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.^[12][13][13] 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.^[14]

In July 2014, the European Commission has announced its targets for the circular economy, waste management and provided a "food waste" definition as "food (including inedible parts) lost from the food supply chain, not including food diverted to material uses such as bio-based products, animal feed, or sent for redistribution" (i.e. food donation). Concurrently, all Member States of the European Union shall establish frameworks to collect and report levels of food waste across all sectors in a comparable way. The latest data are requested to develop national food waste prevention plans, aimed to reach the objective to reduce food waste by at least 30% between 1 January 2017 and 31 December 2025. To enable the process, the Commission shall adopt implementing acts by 31 December 2017 in order to establish uniform conditions for monitoring the implementation of food waste prevention measures taken by Member States of the EU.^[1]

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".^[7] The states remain free to define food waste differently for their purposes,^[8][15] though many choose not to.^[10]

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.^[16] 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.^[17][18] 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.^[16] From planting, crops can be subjected to pest infestations and severe weather,^[19][20] which cause losses before harvest.^[16] 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.^[21] 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.^[16] Economic factors, such as regulations and standards for quality and appearance,^[22] 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.^[16] In urban areas, fruit and nut trees often go unharvested because people either don't realize that the fruit is edible or they fear that it is contaminated, despite research which shows that urban fruit is safe to consume.^[23]

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.^[24] 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.^[24][25] In storage, considerable quantitative losses can be attributed to pests and micro-organisms.^[26] 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.^[27] Losses in the nutritional value, caloric value and edibility of crops, by extremes of temperature, humidity or the action of micro-organisms,^[28] also account for food waste;^[29][30] these "qualitative losses" are more difficult to assess than quantitative ones.^[31] Further losses are generated in the handling of food and by shrinkage in weight or volume.^[16][32]

Some of the food waste produced by processing can be difficult to reduce without affecting the quality of the finished product.^[33] Food safety regulations are able to claim foods which contradict standards before they reach markets.^[34] Although this can conflict with efforts to reuse food waste (such as in animal feed),^[35] 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.^[36][37]

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.^[38] Although it avoids considerable food waste,^[38][39] packaging can compromise efforts to reduce food waste in other ways, such as by contaminating waste that could be used for animal feedstocks.^[40]

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.^[41] Retailers usually have strict cosmetic standards for produce, and if fruits or vegetables are misshapen or superficially bruised, they are often not put on the shelf. In the United States, an estimated six billion pounds of produce is wasted each year because of its appearance.^[42] Addressing this, there are many campaigns focused on raising retailer and consumer awareness about food that is variously termed ugly, imperfect, wonky, and funky.

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.^[43] 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).^[43]

A 2013 report from the British Institution of Mechanical Engineers (IME) likewise estimated that 30–50% (or 1.2–2 billion tonnes) of all food produced remains uneaten.^[45]

Individual countries

New Zealand

Singapore

In Singapore, 788,600 tonnes of food was wasted in 2014.^[46]

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.^[47]

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.^[48] Another survey, by the Cornell University Food and Brand Lab, found that 93 percent of respondents acknowledged buying foods they never used.^[49]

Reduction and disposal

Response to the problem of food waste at all social levels has varied hugely, including campaigns from advisory and environmental groups,^[50] and concentrated media attention on the subject.^[47][51]

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.^[47]

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.^[50]

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).^[52] In Europe, the Food Surplus Entrepreneurs Network (FSE Network), coordinates a network of social businesses and nonprofit initiatives with the goal to spread best practices to increase the use of surplus food and reduction of food waste.^[53]

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.^[54]

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.^[49]

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.^[55]

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.

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,^[56] though not all backyard chicken growers recommend it.^[57]

Composting

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

Food waste can be biodegraded by composting, and reused to fertilize soil. By redistributing nutrients and high microbial populations, compost reduces water runoff and soil erosion by enhancing rainfall penetration, which has been shown to reduce the loss of sediment, nutrients, and pesticide losses to streams by 75-95%.^[58]

Vermicomposting is the practise of feeding scraps to worms who produce fertilized soil as a byproduct.^[59][60][61]

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.^[62] 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.^[63]

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.^[64]

Food Waste Recovery

Food wastes are undesirable for the food industry in terms of sustainability and environmental impact, but perhaps more important in view of high disposal costs. For this reason, they have been considered as a matter of treatment, minimization and prevention for more than 40 years. Nowadays, food wastes account as a source for the recovery of valuable compounds and deal with the prospect of feeding population in the 21st century. Perspectives originate from the enormous amounts of food related materials that are discharged worldwide and the existing technologies, which promise not only the recovery but also the sustainability of high added-value ingredients inside food chain.^[1][65]

See also

• Anaerobic digestion
• Food rescue
• Waste & Resources Action Programme
• List of waste types
• Post-harvest losses (vegetables)
• Source Separated Organics
• Waste management

References

Bibliography

Further reading

• Juul, Selina (2011). Stop spild af mad - en kogebog med mere. Gyldendal. ISBN 87-02-10152-1. 
• Bloom, Jonathan (2010). American Wasteland - How America Throws Away Nearly Half of Its Food (And What We Can Do About It). Perseus Books Group. ISBN 0-7382-1364-0. 
• Stuart, Tristram (2009). Waste: Uncovering the Global Food Scandal. Penguin. ISBN 0-14-103634-6. 
• LeGood, Paul; Andrew Clarke (November 2006). "Smart and Active Packaging to Reduce Food Waste" (PDF): 32. Retrieved 2009-04-28. 
• Willand, Lois Carlson (1979). The Use-It-Up Cookbook: A Guide for Minimizing Food Waste. Practical Cookbooks. ISBN 0-9614556-0-8. 
• Venkat, Kumar (September 2011). "The Anatomy of Food Waste". Retrieved 2011-10-04. 

External links

Wikimedia Commons has media related to Food waste.

• Feeding the 5000 - Global food waste campaign
• United Against Food Waste - European food waste campaign and events
• "wastecooking" - political cookingshow with the aim to call attention to food waste
• This is Rubbish - Welsh anti food waste campaign group
• Stop Wasting Food movement - Denmark's largest non-profit consumer movement against food waste
• Blog on Food Waste - The Huffington Post - Selina Juul's blog on food waste at The Huffington Post
• Taste the Waste - international campaign and film project
• Joint Declaration Against Food Waste - an international document which is disclosed to the European Parliament and the United Nations and contains proposals for sustainable use of food and commitment to the global reduction of food waste by at least 50% by 2025 and also suggests that reduction of food waste should be a new UN Millennium Development Goal.
• SAVE FOOD - United Nations Food and Agriculture Organization (FAO)'s first international congress on food waste SAVE FOOD in collaboration with Messe Düsseldorf
• FAO report 'Global Food Losses and Food Waste' - United Nations Food and Agriculture Organization (FAO)'s report 'Global Food Losses and Food Waste'
• The Climate Change Impact of US Food Waste - CleanMetrics Corp.'s report on the climate change impact of US food waste, based on a life-cycle assessment study using USDA food waste data
• Food Waste Stats
• Food waste reduction could help feed world's starving, article on BBC News website

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