|
 Home
Plastics
Many items used in the kitchen are made of plastic, and this guide displays
the different types and their suitability for certain uses.
Plastics are primarily made from petrochemicals, the main ingredient of
which is oil.
The term "plastics" encompasses organic materials, such as the
elements carbon (C), hydrogen (H), nitrogen (N), chlorine (Cl) and sulfur
(S), which have properties similar to those naturally grown in organic
materials such as wood, horn and rosin.
Plastic can be classified into thermoplastics and thermoset plastics.
Thermoset plastic is heat resistant and can be used for cooking.
Thermoplastic plastic is vulnerable to heat, and can be recycled and
reformed repeatedly.
There are about two dozen important types of plastic,
with many variations. The plastics with which we are most familiar are
listed in the chart below, together with their recycling symbol, their
individual strengths, and their most common uses. |
 |
PET or PETE
polyethylene terephthalate |
Plastic soft drink and water bottles, beer
bottles, mouthwash bottles, cooking oil and salad dressing containers,
boil-in food pouches, processed meat packages
Clear and optically smooth surfaces. Excellent
barrier to oxygen, water, and carbon dioxide. High impact capability
and shatter resistance. Excellent resistance to most solvents. Capability
for hot-filling.
No known hazards. Do not reuse, as surface is porous and hard to
clean. |
 |
HDPE
high density polyethylene |
Milk jugs, detergent bottles, oil bottles, toys, plastic bags
Excellent resistance to most solvents. Higher tensile
strength compared to other forms of polyethylene. Relatively stiff
material with useful temperature capabilities.
No known hazards. |
 |
PVC
polyvinyl chloride
(chlorine and ethylene) |
Food wrap, vegetable oil bottles, blister packaging, as well as plastic
pipes and outdoor furniture
High impact strength, brilliant clarity, excellent
processing performance. Resistance to grease, oil, and chemicals.
Possible interaction when plasticizers (phthalates, DEHA) are added
for greater flexibility. Possible dioxin pollution in manufacture and
incineration. |
 |
LDPE
low density polyethylene |
Bread and produce bags, frozen food bags, squeezable bottles, storage
containers, tote bags, bottles, clothing, furniture, carpet, shrink-wrap,
garment bags, trash can liners
Excellent resistance to acids, bases, and vegetable
oils. Toughness, flexibility and relative transparency for packaging
applications using heat sealing.
No known hazards. |
 |
PP
polypropylene |
Margarine and yogurt containers, caps for containers, wrapping to replace
cellophane, drinking straws, cutting boards
Excellent optical clarity in biaxially oriented
films and stretch blow molded containers. Low moisture vapor transmission.
Inertness toward acids, alkalis and most solvents.
No known hazards. |
 |
PS
polystyrene
(benzene and ethylene) |
Egg cartons, fast food trays, disposable plastic silverware, drinking
cups, packaging pellets (Styrofoam peanuts)
Excellent moisture barrier for short shelf life
products. Excellent optical clarity in general purpose form. Significant
stiffness in both foamed and rigid forms. Low density and high stiffness
in foamed applications. Low thermal conductivity and excellent
insulation properties in foamed form.
Styrene is a suspected carcinogen, and p-nonylphenyl, a suspected
endocrine-disrupting chemical. Do not consumer fatty foods or alcoholic
substances in Styrofoam containers. |
Recyclability is based on individual plastics and the collection
practices of each municipality. |
Other
(Some types are listed below) |
This code indicates that the item is made with a resin other than
the six listed above, or a combination of different resins.
Items classified in this category are dependent on resin or
combination of resins.
|
Teflon
polytetrafluoroethylene |
Cookware, plumbing tape, tubing
Excellent heat resistance. Excellent chemical
resistance. Almost frictionless. |
PVDC
polyvinylidine chloride |
Saran and other food wraps
Excellent impermeability from food odors. Excellent
flexibility.
A type of PVC, potential for pollution during manufacture and
incineration. |
PC
polycarbonate |
Most clear plastic baby bottles, 5-gal water bottles
Contains Bisphenol-A. |
PES
polyethersulfone |
Plastic baby bottles
Non Besphenol-A. |
PLA
polylactide |
Resins based on corn, potatoes, sugar cane and other starch-based
resources.
No known hazards. |
ABS
acrylonitrile-butadiene-styrene |
Appliances, pipes
Durable against impact, high mechanical strength. |
PA
(Nylon)
polyamide |
Packaging, parts, electronics, ropes, brushes
High abrasion resistance, low friction, high tensile
strength. |
PMMA
(Acrylic)
polymethyl methacrylate |
Plexiglas, Lucite, Acrylite
Hard and extremely clear. |
Phenolics
phenol-formaldehyde |
Pan handles, toaster knobs
Hard, strong, inexpensive. Excellent electrical
resistance. |
MF
(Melamine)
melamine-formaldehyde |
Dishware and utensils, electrical components, laminated veneers
Very good heat-, scratch-, and stain-resistance. |
Plastics are controversial because of their environmental impact in both
manufacturing and disposal, and some are also controversial in use. Although
plastics are essential in our daily lives, we can limit their negative
impact by using non-disposable alternatives, when available, and by
recycling.
Sources:
American
Chemistry Council
-
Plastic Packaging Resins (PDF 119KB)
- Facts on
Plastics
-
Using Plastics in the Microwave (PDF 57KB)
U.S. Environmental Protection
Agency
- Profile of the
Plastic Resin and Manmade Fiber Industries (PDF 2.06MB) Includes
history of plastics, method of manufacture, and lots more.
The
Green Guide
- National Geographic Society
Biodegradable
Products Institute
PlasticsIndustry.com
Encarta.MSN.com
Planet Polymers |
