Glass Contamination

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Contamination is the Killer in Glass Recycling

The amazing thing about glass is that it is 100 percent recyclable. It does not wear out and can be recycled over and over again without any reduction in the quality of new glass products. All types of glass have different chemical make-ups that alter their capability to be recycled. Container glass is the only glass that can be turned into cullet to be sold back to bottling plants for the use of furnace-ready cullet. Glass manufacturers have extremely high standards, any foreign material that makes it past the glass recycling processing equipment can cause imperfections in containers, making it potently unsafe to the consumer. This is a big liability concern for the glass manufacturer. The success of glass recycling depends on good quality glass coming back for processing, free from contamination.

What Contaminates Glass?

Some glass products are not suitable for recycling. They contain heavy metal oxides that can contaminate recycled glass and result in imperfection and poor quality product. Even the smallest amount of contamination will alter the chemistry of glass recycling, making the final product unusable. Contaminants include:

  • Ceramics (dinner plates, coffee mugs)
  • Window glass & mirrors
  • Plastic, tin, aluminum lids/tabs
  • Pryex glass
  • Wired glass
  • Crystal & drinking glasses
  • Light bulbs or tubes

Ceramic Contamination
Example of ceramic contamination.

Just one ounce of ceramic can contaminate a whole ton of glass. The whole ton of glass then has to go to the landfill, because there is no way to efficiently separate out the contamination.

Iron Contamination
Example of iron contamination

Many people wonder why there are three colors used in the manufacturing of glass bottles. The reason is a simple. Most products are placed in clear bottles, called flint, to enhance product appeal. However, some products degrade if exposed to sunlight. Bottling companies make green or amber (brown) glass to enable longer product shelf life. This is why bottling plants only accept one of the three colors for processing. There is no special equipment to separate glass into three colors, so separation is done by hand. This may be performed by the recycler collecting the glass or by the public dropping off glass at separating bins. Rinsing containers to remove traces of food and beverages helps with odors that attract insects and rodents. Also, be careful not to break the containers when depositing the glass into collection bins, this ensures better safety for yourself and recycling workers. Quality control is a job we must all perform!

Please only deposit glass bottles and jars in the recycling bins!

Glass Bottles