Plastics Industry
 


Plastic and the Environment


Plastics are used throughout the world for a broad number of reasons. Although plastic is certainly a globally important product, there are many environmental concerns associated with its use.

Impacting the Environment

One of the positive characteristics of plastic is the fact that it is durable. Unfortunately, this is not a positive characteristic when it comes to the environment. The fact that plastic is durable means it degrades slowly. In addition, burning plastic can sometimes result in toxic fumes.

Aside from trying to get rid of plastic, creating it can be costly to the environment as well. It takes large amounts of chemical pollutants to create plastic, as well as significant amounts of fossil fuels.

On the other hand, some argue that plastic helps the environment is several ways, as well. After all, plastic has been used to make cars lighter. As a result, less oil is used to mobilize the cars and less CO2 is emitted. In addition, plastic containers provide safe ways for disposing of toxic waste products.

Recycling Plastic

Plastic recycling became somewhat commonplace in the 1990s. Thermoplastics were melted and used again and thermoset plastics were ground up and used for filler. Unfortunately, the purity of these plastics was compromised each time it was reused. To assist in the plastic recycling program, the Plastic Bottle Institute of the Society of Plastics Industry created a method for marking plastic bottles in order to determine what type of plastic it is made of.

A triangular symbol made of three "chasing arrows" containing a number in the middle and special letters on the outside is used to identify the different types of plastic. The following are the letters of identification and their meaning:

  1. PETE - Polyethylene Terephthalate - PETE is most often used for cooking oil bottles, soft drink bottles, and peanut butter jars.
  2. HDPE - High Density Polyethylene - HDPE is commonly used for milk jugs and detergent bottles.
  3. PVC - Polyvinyl Chloride - PVC is used for plastic pipes, water bottles, outdoor furniture, shrink-wrap, liquid detergent containers, and salad dressing containers.
  4. LDPE - Low Density Polyethylene - LDPE is often used for trash can liners, dry-cleaning bags, produce bags, and food storage containers.
  5. PP - Polypropylene - PP is used for drinking straws and bottle caps.
  6. PS - Polystyrene - PS is used to make packaging pellets, commonly referred to as "Styrofoam peanuts."
  7. OTHER - Plastics listed in the OTHER category are any not listed in the first six categories. Certain types of Tupperware and other food storage containers commonly fit within the OTHER category.

The many different types of plastic has made recycling plastic difficult, particularly because the process of sorting plastics cannot be automated. In fact, recycling plastic is labor intensive since reading the special triangular symbol can only truly identify most plastic items.

Biodegradable Plastic

Currently, there is research taking place in the area of biodegradable plastic. The goal is to develop a type of plastic that can naturally break down from exposure to sunlight. By mixing starch with the plastic, it can be made to degrade more easily. It does not, however, cause the plastic to break down completely.

A genetically engineered bacterium capable of synthesizing biodegradable plastic has also been developed. This material, however, is quite expensive to create at this point. Currently, BASF does make a biodegradable polyester called Ecoflex that is used for food packaging applications. Unfortunately, carbon gets locked up in these biodegradable plastics and is released into the atmosphere as carbon dioxide.

Another downside to these biodegradable plastics is that they require sunlight to degrade. Therefore, this type of plastic really only helps with roadside litter. Plastics buried in landfills will not receive the sun they need to degrade and, therefore, can still last for decades.

While there are still many questions left unanswered when it comes to the environment and plastic, it is clear plastic is here to stay for a very long time.


 

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