The composition of municipal solid waste (MSW) varies depending on the collection time of the day, region, income levels, number of inhabitants, economic activities, and pattern of consumption. Therefore, the definition of organic fraction of municipal solid waste (OFMSW) is different depending on the location/country. For example, in the United States of America, the OFMSW is composed of food, garden wastes and paper, while in the European Union (EU), it is composed of wastes from parks, gardens and kitchens. According to the World Bank study in 2018, two billion tons of MSW are generated annually in the world. As per this study, the organic waste represents 44 % of the total waste generated globally. This percentage varies according to the income level of the countries, as it can be observed in Table 1. Thus, for high, medium and low-income countries, the food and green wastes represent 32, 53 and 57 % of the total waste generated, respectively. The elemental composition of OFMSW from different countries is presented in Table 2. This table indicates that an average of 46 % of the OFMSW is carbon that can be recovered to be used instead of being released to the atmosphere.
From a holistic viewpoint, waste management comprise of the measures taken, technologies used, and all other activities involved from the collection to dumping of solid wastes. Some of the eco-friendly practices of waste management are segregation, recycling and composting. The 4Rs namely refuse, reduce, reuse and recycle is an efficient way of managing solid waste by reducing the amount of waste generation. However, the policies related to the management of MSW varies among different countries.