Plastic Number Four

Resin code number four is low-density polyethylene. You may know it by the abbreviation LDPE. Low-density polyethylene is used for grocery bags, food wraps, squeeze bottles, bread bags, plastic bags, six-pack rings, and lab equipment.

Low-density polyethylene is a thermoplastic made from the monomer ethylene. It was first produced in 1933 and was the first grade of polyethylene. Its use as a film quickly made it a revolutionary plastic. LDPE can be flexible or rigid, depending on the desired application. 

Rigid low-density polyethylene can usually be recycled curbside by your municipal facility. Flexible low-density polyethylene must be dropped off at plastic film recycling bins at stores such as Target or Lunds. According to the EPA, only 5.7 percent of LDPE is recycled. Due to this low rate of recycling, plastic number 4, as well as all plastics, carries a very high carbon footprint. 

Low-density polyethylene can be recycled into shipping envelopes, garbage can liners, floor tile, paneling, furniture, compost bins, trash cans, landscape timber, and outdoor lumber. 

LDPE, like other forms of polyethylene, is considered "safe" due to its low risk of leaching. This plastic, like all other plastic, still carries risk. One study found that 95 percent of all plastic tested was positive for estrogenic activity, making plastic a known hormone disruptor. 

Take the time to recycle the plastic that you use and try to reduce the amount of plastic that you use overall. Invest in a few reusable grocery and produce bags to do your part.