In this chapter, the method and theory will be discussed regarding to this research which reveals the knowledge that gained via resources such as reference book, newspaper, journal, articles and documentation regarding application and research work. The study is very essential in order to get more understanding in occupational safety, health, and environment.
Food Packaging Plastic
In the food packaging field, there is a flexible packaging which is envelopes, sachets, bags, and wraps that easily be sealed to get the shape (LOKENSGARD, ERIK, 2010). Food packaging is a main part of the food industry. In informing consumers which types of plastics are recyclable and which are not by implementing the use of resin identification coding for each type of plastics in order to help (COUNCIL, n.d.). In United State at 10.9 billion, the third largest industry of manufacturing is plastic. The main components of common food packaging plastics with usage of polystyrene (PS), high-density polyethylene (HDPE), polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET) and low-density polyethylene (LDPE). The types of plastics are used correlate with the numbers of resin 1-6. A plastic other than the common 6 or a mixture of the 6 and have varying properties depending on the composition of the plastics. In a certain way food packaging plastic is used due to their unique properties.
A rigid form or heat resistance are required for cups and Styrofoam food containers as well as egg and meat trays that normally used PS (Bernardin III, 2007). Bottles and clouded containers for foods such as milk that needed a strong material has been used HDPE. Two types of plastic bags have made from HDPE and LDPE. HDPE bags can be recycled while LDPE bags are not recycled currently. According to (Person R.B, 1982) , clear plastic wrapping mostly has been used PVC that will be stretching as well as being easy to extrude into sheets and cheap cost. LDPE that used for food storage bags because it has a large stretch capacity as well as having excellent barrier properties and very low cost (Pedroso, 2005). In (Sahin, 2005) stated ,the baby bottles, bowls and cups known as rigid container that used PP because of its high strength properties, in spite of the fact that it is marginally costlier than different plastics.
After processing, PET as the example of plastic that has a good tensile and yield strength properties as well as being transparent but melts very easily, then it suitable for cold beverages which require a strong material to contain the liquid while preventing chemical interactions (Girija, 2005). Because of the differing properties of the category \”Other\”, it can be utilized for a variety of things from 3-5 gallons of water jugs to oven-bake bags (COUNCIL, n.d.).
The Effect of Plastic for Health
The monomeric building block of polycarbonate plastics known as a Bisphenol A (BPA). It is a chemical that has been used to harden plastics for years. For several years food packaging plastics have been used, which is additives within material-food interaction to leak into the food have been discovered. As previously discussed, the additive to incorporate itself within the material and allowing the molecular structure the plastic to change by integrating into the matrix of a polymer (Kerry, 2006). In many cases, this can be toxic, because of the leaching the barrier and mechanical properties in plastics are lost also causing harm to those who consume the food as well as allowing the food to become contaminated with bacteria (Hourston, 2010). According to (Wong, 1988), the chemical from plastic would leach when PVC polymers reached temperatures greater than 100˚C (Ahmad, 2007). Styrene chemicals and additives from the cup would leach into the water whenever hot water was poured. Food packaging polymers that through microwaving and heating can leach dangerous toxins from the plastics into food (Hourston, 2010). The effect of the hormone estrogen in the animal by imitating an endocrine disrupter from BPA. Breast tissue and neonatal/fetal prostate gland undergoing changes which are some of the estrogen-like effects that associated with BPA (CONTROL, 2012).
BPA can be found in the epoxy resin lining of cans for food and infant formula. BPA levels increased 69 percent if cold beverages from polycarbonate bottles have been drunk by college students (CONTROL, 2012). In the indoor air in high levels, phthalates are also found in many plastics (Katie, 2017). Phthalates harmful linked to reducing testosterone, infertility in men, immune system impairment and so on (Katie, 2017). There are several many of different kind of phthalates, for short and the best studied isdiethylhexyl phthalate, or DEHP (Fellman, 2009). Phthalates are also commonly found in wood finishes, air fresheners, perfumes, medical equipment, and cosmetics. In the creation of plastics and other materials, phthalates have played an important role that has many versatile uses in consumer products, in medicine and in the industry (Greenfacts, 2005).