Waste classification

What is waste classification?

Waste classification is the process of selecting and grouping solid and liquid waste generated by different human activities. This classification makes its management, treatment, and use easier.

Likewise, waste is understood as any material considered expended and which must be eliminated after completing its mission since saving it is considered to have no value. However, this term has evolved over time: now, we understand that waste can be reused and recycled. 

How is waste classified?

There are three key criteria for classifying waste:

1. According to their origin: 

• Domestic: these are generated in the home, and they may be organic or inorganic, recyclable or non-recyclable.
• Municipal: these are managed at a local level, and they come from streets, markets, gardens, etc.
• Industrial: this may be hazardous waste or chemical or radioactive substances, depending on the industrial activity from which they come. 
• Commercial: these arise from any business, such as food or clothing stores. 
• Hospital: medical material, which can also be considered hazardous waste, which is more difficult to manage. 
• Construction: while these are not dangerous, they are difficult to handle due to their large volume.
• Mining: solid, liquid, or paste residues resulting from the use of a geological resource. 
• Radioactive: these contain chemical elements. 

2. According to their biodegradability:

• Organic: these are biological in origin; they come from vegetable, animal, or edible materials and are biodegradable, which means that nature itself can use them in its decomposition process. 
• Inorganic: these are not composed of biodegradable matter but are of an industrial or artificial nature – for instance, plastic bags, bottles, metal objects, etc. They usually take a long time to break down. 

3. According to their level of danger:

• Inert: this includes all waste that does not undergo significant changes at a physical, chemical, or biological level when deposited in landfills. 
• Hazardous: due to their characteristics, this waste poses a risk to both the environment and living beings. For the most part, these are oils, solvents, and containers that have held hazardous substances.
• Non-hazardous: this is all waste that does not fall into the two previous categories, such as plastic, paper, or metal, as long as they have not been in contact with dangerous substances. 

There is a fourth type of classification determined by the composition of the waste; it is at the heart of the concept of recycling. This waste is deposited in different containers to process them together subsequently. They are divided into paper and cardboard; containers like cans, tetra bricks, and plastic bottles; glass; and other waste such as metal, wood, paint, batteries, etc. 

What are the advantages of classifying waste?

As a result of the awareness of the importance of reducing, reusing, and recycling to help protect the environment, the classification of waste has gained great significance at an ecological and economic level over time. The advantages of classifying waste include:

• Saving energy and natural resources in producing new materials. 80% of urban waste can be used, so its classification would reduce the need to extract raw material.
  
• Contributing to job creation. According to the UN, the recycling sector employs 12 million people in the United States, China, and Brazil alone as a result of waste classification. 

• Reducing pollution from depositing and burning waste in landfills by reincorporating waste in the domestic, industrial, and commercial circuits. 

• Properly managing waste that prevents the dispersion of dangerous substances and, thus, conserving raw materials and living beings. 

What is the outlook for waste classification worldwide?

• According to a study by the United Nations, around 11.2 billion tons of solid waste are collected annually in the world; its disintegration contributes to 5% of global greenhouse gas emissions. 

• As for plastic waste management, only 9% of everything generated throughout history has been recycled worldwide; 79% has accumulated in landfills, garbage dumps, or in the environment, while 12% has been burned. 
• Since 2000, the World Bank has allocated more than $4.7 billion to finance nearly 350 solid waste management and classification programs around the world.

• According to Spain’s National Institute of Statistics, about 48% of the country’s processed waste ends up in landfills, 38% is recycled, 10% is reused, and 3% is incinerated.