Plastics have been an integral part of our daily lives for over a century. With plastic production soaring to 107 billion pounds in North America alone in 2002, it’s crucial to delve into its creation, identification, and potential health implications. Let’s explore the diverse types of plastics and how to use them safely.
Plastic Production
The complex process of crafting plastic starts with carbon derived from petroleum, natural gas, coal, or biological sources. These elements are meticulously combined to yield diverse properties, resulting in products ranging from sturdy house siding to flexible shrink wrap.
Plastic Resin Identification
Have you ever noticed the number with the arrows surrounding it on your plastic bottles? Many people use these numbers to determine how the product is to be recycled. These numbers are called the plastic packaging resin identification codes. They indicate the type of plastic that the item was made from and are used to help consumers know whether and how the item is to be recycled. According to the American Chemistry Council, the resin identification numbers are as follows:
- No. 1: PET (Polyethylene Terephthalate)
- No. 2: HDPE (High-Density Polyethylene)
- No. 3: PVC (Polyvinyl Chloride)
- No. 4: LDPE (Low-Density Polyethylene)
- No. 5: PP (Polypropylene)
- No. 6: PS (Polystyrene)
- No. 7: Other (Multi-layer combinations or alternative resins)
Safety Measures in Plastics Usage
Before using plastic for food storage, understand the rigorous testing process it undergoes to ensure safety. The FDA assesses potential leaching and toxicity, aiming to guarantee that the plastic poses no health risks during its intended use.
Key Plastics: Characteristics of specific plastics
- PET (No. 1): Clear, tough, and shatterproof, ideal for carbonated beverage bottles.
- HDPE (No. 2): Boasting good barrier properties, perfect for milk, juice, and water bottles.
- PVC (No. 3): Rigid or flexible, used in medical bags, shower curtains, and construction materials.
- LDPE (No. 4): Known for toughness and flexibility, used in grocery bags, garbage bags, and more.
- PP (No. 5): Noted for its high melting point, suitable for hot liquids in containers.
- PS (No. 6): Versatile plastic used in protective packaging, food serving items, and more.
Bisphenol A (BPA) Awareness
The health risks of BPA have been receiving considerable attention. It has long been known that previous studies done on lab animals showed that BPA can cause genetic damage. BPA was approved for use with humans because the amount given to the animals was not comparable to what humans consume. For example, the intake of BPA is expressed in milligrams (mg) per kilogram (kg) of body weight (bw) per day. The highest estimated daily intake (exposure) for humans is
- less than 0.0147 mg/kg bw/day for children;
- less than 0.0015 mg/kg bw/day for adults; and
- 0.0100 mg/kg bw/day for workers exposed to this chemical.
Studies done on laboratory rodents have shown that high doses of BPA during pregnancy and lactation can reduce survival, birth weight, and growth of offspring early in life, and delay the onset of puberty. The doses given were significantly higher than the estimated human exposures:
- Delayed puberty: greater than 50 mg/kg bw/day
- Growth retardation: greater than 300 mg/kg bw/day
- Survival: greater than 500 mg/kg bw/day
BPA has also been linked to cancer, diabetes, and obesity in animals. The American Chemistry Council states that “consumers would have to eat more than 500 pounds of food and beverages in contact with polycarbonate plastic or epoxy resins every day of their lives to exceed exposure levels determined to be safe by the European Food Safety Authority and the U.S. Environmental Protection Agency.” There is no way to know for sure if humans would have the same reaction that the animals have had, but there is enough evidence to be concerned and warrant further studies.
Guidelines for Safe Plastics Use
Heed expert advice from Professor Fredrick S. vom Saal on choosing safer plastics (No. 2 and No. 5). Additionally, follow essential guidelines such as recycling instead of reusing, avoiding high temperatures for BPA-containing items, and using plastic products strictly for their intended purposes.
Conclusion
While plastic remains an integral part of our lives, understanding its production, identification, and potential health implications is crucial. By adopting informed practices and choosing plastics wisely, we can navigate the world of plastics with greater awareness and safety.
More Information on Plastics
Environmental Protection Agency
http://www.epa.gov/NCEA/iris/subst/0356.htm
National Institute of Environmental Health Sciences
http://www.niehs.nih.gov/news/releases/2007/bisphenol.cfm
American Chemistry Council
http://www.americanchemistry.com/s_plastics/index.asp
Plastic Alternative Links:
BPA free bottles and sippy cups
http://www.newbornfree.com/