Plastics Explained

Plastics Explained

What is Plastic?

Plastic is a synthetic material that is made primarily from natural gas, oil, and coal. Plastics are synthetic polymers - polymers meaning they are long repeating chains of molecules and synthetic meaning they are chemically bonded together by human processes. Polymers do occur in nature, such as cellulose in plants, but the prevalent plastics that we use today are synthetic and therefore do not occur in nature. The name for many plastics actually starts with “poly-” to describe the type of repeating molecule it is made of. For example, polystyrene (commonly known as Styrofoam), is a material that is made from many repeating units of connected styrene molecules.

The ability for plastic to be molded into various forms is one of the main reasons for its widespread use in so many products. Plastic is flexible, durable, and lightweight, which makes it an attractive material for many applications. While plastic has made advancements in many areas of our lives from sterile medical packaging to electrical wiring, the overuse of it in our lifestyles today as a single-use disposable product is unsustainable. The characteristics that make plastic such a useful material are some of the very reasons it is such a harmful pollutant.

Plastics Recyclability

We get it - plastics recycling can be confusing. There are many different factors that contribute to a plastic’s recyclability, including the type of plastic, the ability to effectively recover it, whether markets exist for that plastic, and more.


When it comes to curbside recycling, the predominant messaging that was given across the U.S. as a means to make it easier for the public to understand was “plastic containers labeled #1-#7”. The reality is that not all of these plastics are recovered and recycled to the same degree, with ever increasing variability as the amount and types of plastic containers and packaging climbs.


#1 and #2 plastics have the strongest domestic recycling markets, followed by #5 plastics, while #3, #4, #6, and #7 plastics are the hardest to recover and lack strong recycling markets. Specifically, the #1 and #2 bottles and jugs have strong domestic recycling markets. When we start getting into non-bottle shaped variations of these plastics, recovery becomes more difficult and the likelihood of them being recycled is lower due to a variety of factors. This is because bottles/jugs (those containers with a narrower opening compared to the body) are made differently than other containers of the same number plastic and therefore require a different type of reprocessing to be made into a new product.


Plastic tubs, typically #5 plastic, also have domestic recycling markets available. But, the term “tub” can open up a lot of room for individual interpretation. When we say tub, we are referring to tubs that come with snap on lids (items such as cottage cheese and yogurt), not clamshell containers, frozen food trays, or cups


The consequence of the #1-#7 messaging is that people are focusing more on the plastic numbers, which were actually not originally intended as a means to communicate with consumers, than the message of plastic bottles and tubs. Curbside recycling was designed to recover clean rigid, three-dimensional plastic bottles and tubs. With the increase of plastic packaging types and variability in recycling markets the ability to message exactly which plastics are and are not accepted becomes increasingly difficult.

The many complexities and variability with plastics recycling markets and the fact that most plastics are downcycled are two of the big reasons why we urge individuals to find reusable alternatives to their plastic products whenever possible. Tips to reduce and reuse single-use plastics are available on our Plastic Pollution Solution webpage.

Plastics Toxicity

We are still learning more about the toxicity of plastics everyday from news articles about plastics in seafood, in soils, and even in the air we breathe. Beyond these sources of plastic that result from plastic pollution in the environment, plastic can be toxic to us even before it is breaking apart into pieces in the environment. Certain plastics are notorious for their high toxicity, such as polystyrene (most commonly known as Styrofoam). According to the World Health Organization, Styrene, the building block of polystyrene, is a probable human carcinogen. Some studies suggest that microplastic leaches from plastic bottles into water. From the multiple ways we are exposed to plastic, it is estimated that we consume the equivalent of the weight of credit card of plastic per week. 


While we still have yet to discover the impacts of plastics on our bodies, we believe these potential risks are even more reason to reduce our use of plastics whenever possible - especially those that come into contact with our food and drinks.


Reduce & Reuse Single-Use Plastics

Single-use disposable items have become increasingly popular because of their convenience, but that doesn't mean reusable alternatives are inconvenient - they just take getting used to! Try making one change at a time, such as getting a reusable water bottle, and once that becomes comfortable try another one, such as a reusable shopping bag. Over time you can phase out single-use plastics from your lifestyle, which will help conserve natural resources and protect the environment from plastic pollution. 

Transitioning away from single-use plastics is a process. Be patient - changing a habit doesn't happen overnight and just because you're ditching single-use plastics doesn't mean the rest of the world is (yet!). You may inadvertently get those pesky plastics in your life, whether someone gave you something in a plastic bag or you forgot your reusable water bottle that day. No need to despair! There are many ways to reuse those items to make the most use out of the resources extracted from the planet.


Reduce Single Use Plastics

Guide to Plastics #1 - #7

#1 PET or PETE Polyethylene Terephthalate

Plastic #1


The City of Ann Arbor accepts all #1 bottle and tub-shaped containers in the curbside recycling program. #1 bottle shapes are accepted in other recycling programs throughout Washtenaw County. Non-bottle shapes of #1 PET are less commonly recycled. If your hauler is not Recycle Ann Arbor (who accepts this), check first.  


COMMON PRODUCTS (MARKED/ LABELED): Plastic beverage containers (soft drink, water, and juice bottles, etc.), plastic food containers (peanut butter, salad dressing, etc.) 

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Food and beverage bottles and containers, fleece wear, polyester, carpet, luggage


#2 HDPE High-density polyethylene

Plastic #2


The City of Ann Arbor accepts all #2 bottle and tub-shaped containers in the curbside recycling program. All #2 plastics of any size, shape or color are accepted at the Drop-Off Station as well as these public locations throughout Washtenaw  County. #2 bottle shapes are accepted in most curbside recycling programs in Washtenaw County. Non-bottle shapes of #2 HDPE are less commonly recycled, so check with hauler before recycling. Empty, clean and dry #2 shopping bags can be dropped off at our Drop-Off Station and several grocery stores throughout the County, including Kroger and Meijer. 


COMMON PRODUCTS (MARKED/ LABELED): Consumer product bottles (shampoo, conditioner, liquid laundry detergent, vitamin, motor oil and similar bottles). Grocery/retail bags.

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Bottles, pipes, buckets, crates, flower pots, floor tiles

#3 V or PVC Polyvinyl chloride 

Plastic #3


The City of Ann Arbor does NOT accept #3 containers in the curbside recycling program. #3 plastic is not easily recyclable in traditional recycling systems. Just one #3 PVC bottle can contaminate an entire half-ton of water bottles for recycling. Always double check your recycler's requirements before adding any #3 items.


COMMON PRODUCTS (MARKED/ LABELED): Plastic packaging for electronics & toys.

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Mud flaps, cassette trays, garden hoses, electrical cords, cables


#4 Low-density polyethylene 

Plastic #4


The City of Ann Arbor does NOT accept #4 bottle and tub shaped plastics in the curbside recycling program. All #4 plastics of any shape, size, or color are accepted at the Drop-Off Station. Empty, clean and dry #4 shopping bags are accepted at the Drop-Off Station and several grocery stores throughout the county, including Meijer and Kroger. Do not place any plastic grocery bags in curbside recycling bins, as they can clog the gears in mixed recycling plants.


COMMON PRODUCTS (MARKED/LABELED):  Squeezable bottles (honey, mustard, etc.)

COMMON PRODUCTS (UNMARKED/ UNLABELED): Shrink wrap, greenhouse film, stretch wrap, bubble wrap, consumer paper packaging (toilet paper, paper towel), other bags (grocery bags, thicker newspaper bags, bread bags, clear plastic dry-cleaning garment bags. 


#5 PP Polypropylene

Plastic #5


The City of Ann Arbor accepts bottle and tub shaped #5 plastics in the curbside recycling program. #5 plastic is not generally collected with most recycling programs in Washtenaw County. Clean and dry #5 PP caps may be recycled at the Drop-Off Station.  



COMMON PRODUCTS (MARKED/ LABELED): Yogurt and margarine tubs, prescription medicine bottles, some food bottles (ketchup, etc.)

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Landscape borders, auto battery cases, oil funnels


#6 PS Polystyrene

Plastic #6

RECYCLABILITY: The City of Ann Arbor does not accepts #6 bottle and tub-shaped plastics in the curbside recycling program.

No Styrofoam.  #6 PS may be recycled at the Drop-Off Station. 

COMMON PRODUCTS (MARKED/ LABELED): Styrofoam (egg cartons, carry-out food containers, packing peanuts, etc.)

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Styrofoam (or similar) products  

#7 Any other plastic

Plastic #7

RECYCLABILITY: The City of Ann Arbor does not accepts #7 bottle and tub-shaped containers in the curbside recycling program. Can contain PVC, PLA, BPA or just layers of #5 PP and nylon or rayon. The unknown mixture of #7 plastic resins makes it difficult to recycle. 

COMMON PRODUCTS (MARKED/ LABELED): Nalgene (or similar) bottles, CDs, Some food and non-food product containers

REUSED IN THESE RECYCLED CONTENT PRODUCTS: Reusable plastic beverage bottles.