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Understanding Plastics

Understanding Plastics

Although the City of San Leandro encourages plastic recycling, the reality is that many plastics, particularly those used in packaging, are designed for disposal. Plastics have limited market value because of their light weight, and some plastics can contain harmful or even toxic additives. Single-use food packaging has an extremely short useful life (it exists for that one snack or meal) and it is not typically recycled or even recyclable due to food contamination. Plastics litter our streets, sidewalks, and open spaces, and migrate into local waterways where they adversely affect wildlife.

So what should you do with your plastic? The easy answer is:

polystyrene cup in creek

the amount of plastic you use.

Reuse containers, but not for food.

Recycle plastics where feasible.



Since recovery rates for all plastics are low and some plastics have little or no market value for recycling even if they are accepted in your curbside program, you should reduce your use of plastic products and packaging and eliminate the types of plastics that are toxic and/or not recyclable. 

You can do this by:reusable shopping bag

  • Not purchasing disposable plastic cups or plates; paper versions are available and compostable in your green cart;
  • Using durable/reusable shopping bags when you go to the store;
  • Using a reusable water bottle rather than purchasing individually bottled water or drinks; refrain from using reusable bottles made from plastic.
  • Refusing plastic packaging from retailers or only purchasing from retailers that use little or no plastic packaging;
  • Dining at restaurants that use durable dishware, and sharing plates rather than taking leftovers home;
  • Getting takeout from restaurants that use paper or aluminum containers and refusing extra plastic bags, disposable utensils, straws and individually packaged condiments;
  • Seeking durable and recyclable alternatives to plastics products or packaging such as those made of metal, paper or glass.

Eliminate non-recyclable and potentially toxic plastics:

Polyvinyl Chloride (PVC)  PVC Pipe

recycle symbol #3Although PVC is fairly durable, it is not recyclable in curbside programs and can be highly toxic if burned. PVC can be found all around your home because it is used to make window frames, pipe, siding, floors, shower curtains, toys, and a host of other consumer products. Eliminate PVC by not purchasing plastic wrap or products packaged in containers marked with the #3 symbol, and by selecting construction materials not made from vinyl. PVC bottles (for personal care and automotive products) look exactly like other types of plastics so check packaging carefully before you buy.

Polystyrene (PS)plastic utensils

recycle symbol #6While PS is commonly thought of as the white foam material used for food packaging and packing peanuts, it is also made into rigid clamshell containers, coffee cup lids, and plastic utensils; which are ubiquitous even in cities that have actively banned foam takeout containers. PS is not recyclable in curbside programs. Because it is so lightweight, it is often a component of litter and as it breaks down in creeks and other waterways it poses a threat to birds and aquatic life. Eliminate your use of PS by simply saying, “No Thanks”. Let your online vendors know that you do not want your products shipped to you in foam peanuts or blocks and let your local restaurants know that you want your food packaged to-go in paper or aluminum trays instead. And, when you go to the coffee shop, bring your own commuter mug!

Polycarbonate – Bisphenol A (BPA)

water bottle

recycle symbol #7The chemical, BPA, can be found in a wide array of reusable plastic products such as baby bottles, sippy cups, baby toys, reusable food containers, and reusable water bottles and can leach from the plastic into your food.  BPA is a chemical that mimics estrogen and is thought to affect human reproduction, the immune system, and could possibly increase the likelihood of certain cancers. You can eliminate BPA in your home (and diet) by simply switching to reusable glass or metal containers for your food and beverages. If plastic containers are more convenient, choose products that specifically state that they are BPA free.



Although most plastic containers are fairly durable, they are not designed to be used over and over again for food and beverages. After a few uses, plastic bottles and containers will start to degrade and chemicals can leach into your food; and it is an even bigger problem if your food contains fats and/or you heat food in the container. You should never heat leftovers in plastic containers or with plastic wrap. Although some prepackaged foods are designed to be cooked in plastic bags or trays, the packages are designed to be heated only one time. Of course, you can remove the plastic packaging before you cook the food if you are concerned about chemical leaching.

Here are just a few ways to reuse plastics:

  • Refill water bottles and freeze them for a handy ice pack for the cooler - no more expensive packs and no more water-logged food. 
  • Purchase a kit to convert a 1 liter soda bottle into a bird feeder for your backyard.
  • Cut detergent bottles in half and use them as scoops around the house. 
  • Purchase bulk cleaning product to refill your spray bottles. Or, make your own environmentally friendly vinegar and water solution to fill a used bottle.  
  • Reuse plastic bags before you recycle them. Although grocery bags might seem perfect for trash can liners or for cleaning up after your pet, they are probably more bag than you really need. Use smaller bags for waste and save the larger bags for reuse and recycling.
  • Reuse lunch meat and dairy containers for storing craft supplies, hardware, school supplies and small toys


The symbol on plastics is intended only for identifying the type of plastic resin; it doesn’t necessarily mean that the plastic will get recycled if you put it in your recycling cart. Most curbside recycling programs accept plastic containers marked #1-#7, but only #1, #2 and #4 may be actively recycled. All other plastics have limited value and may only be recycled when market conditions are favorable; #3-#7 plastics are often bundled together for sorting and processing in developing nations where the final disposition is unknown.

Here is a guide to plastic resin codes: 

Polyethylene Terephthalate (PET)


Picture of water bottle

Clear and durable; the most commonly recycled plastic

Common uses: Soft drink and water bottles; mouthwash bottles; peanut butter containers; salad dressing and vegetable oil containers; and food trays.

Recycling: collection through curbside recycling programs. Containers marked CRV can be turned in for a refund at certain recycling centers.

Recycled Into: Polar fleece, fiber, tote bags, furniture, carpet, paneling, straps, and new bottles.

Recycle symbol #1

High-Density Polyethylene (HDPE)


Picture of OJ bottle

: Opaque and highly durable with good chemical resistance

Common uses: Milk jugs and juice bottles; bleach, detergent and household cleaner bottles; shampoo bottles; some trash and shopping bags; motor oil bottles; chemical containers; and cereal box liners

Recycling: Containers are collected through curbside recycling programs.  Some service providers will accept bags in the recycling cart if bundled, but check before you place them in your cart; loose bags can jam sorting equipment at recycling facilities. Your best bet is to recycle bags and film plastics at your local grocery store.

Recycled into: Laundry detergent bottles, oil bottles, pens, buckets, recycling carts, floor tile, drainage pipe, lumber, benches, picnic tables, and fencing

recycle symbol #2

Polyvinyl Chloride (PVC)

vinyl window

Often used in construction materials because it is very durable; emits highly toxic dioxins when heated or burned.

Common uses: Shrink wrap, shower curtains, medical equipment, siding, window frames, and piping.

Recycling: PVC containers are accepted in curbside recycling programs, but are typically bundled together with other plastics because of their limited market value. PVC containers can be mistaken for other resins and can contaminate loads of PET & HDPE.  Other PVC products are not recyclable through curbside recycling programs.  

recycle symbol #3

Low-Density Polyethylene (LDPE)

plastic bag

Tough and very flexible; commonly used to make grocery bags.

Common uses: Squeezable bottles; bread, frozen food, dry cleaning and shopping bags; tote bags; carpet; and toys

Recycling:  Some service providers will accept LDPE bags in the recycling cart if bundled, but check before you place them in your cart; loose bags can jam sorting equipment at recycling facilities. Your best bet is to recycle bags and film plastics at your local grocery store. 

Recycled into: Trash can liners and cans, compost bins, shipping envelopes, paneling, lumber, and landscaping ties.

recylcle symbol #4

Polypropylene (PP)

yogurt container

Has a high melting point and can be used for containing hot liquids

Common uses: Dairy containers, lunch meat containers, syrup bottles, ketchup bottles, caps, straws, medicine bottles; and take out containers.

Recycling: PP containers are accepted in curbside recycling programs, but are typically bundled together with other plastics because of their limited market value. Some companies, like Stonyfield Farms, have takeback programs.

Recycled Into: Signal lights, battery cables, brooms, brushes, auto battery cases, ice scrapers, landscape borders, bicycle racks, rakes, bins, pallets, trays.

recycle symbol #5

Polystyrene (PS)

Foam takeout  containers

commonly known as Styrofoam, but is also made into a variety of solid food service ware products such as plastic utensils, coffee lids, and clear clamshell containers.  PS foam is lightweight and breaks down easily which makes it a common component of litter.  

Common uses: disposable plates and cups, meat trays, egg cartons, carry-out containers, utensils, coffee cup lids, packing peanuts, and foam blocks.

Recycling: Foam PS products (blocks, peanuts, and takeout containers) are not accepted in the curbside recycling programs. Rigid PS containers are accepted in curbside recycling programs, but are typically bundled together with other plastics because of their limited market value.  Foam peanuts are suitable for reuse and some companies collect foam blocks for recycling but only in truckload quantities. 

recycle symbol #6


5-gallon water bottle

 consists of a wide variety of plastic resins that don't fit into the previous classifications. Some plastics marked #7 are made from plant sources.

Common uses: Three- and five-gallon water bottles, 'bullet-proof' materials, sunglasses, DVDs, iPod and computer cases, signs and displays, certain food containers, and nylon

#7 plastics containers are accepted in curbside recycling programs, but are typically bundled together with other plastics because of their limited market value. Other #7 plastic products are not accepted in curbside recycling programs but you can recycle disks, tapes, cds at some electronics recycling centers and periodic City events.  See our events page.


recycle symbol #7

Can I compost plastics made from corn and other plants marked with a #7 resin code?

While plastics made from plants may be considered “biodegradable” or “compostable”, the City of San Leandro does not allow businesses or residents to place these materials in their green carts for composting.  The facility that composts San Leandro’s food and yard trimmings cannot compost these products and considers them a contaminant; this includes containers, cups, plates, bags and utensils.


For more information:

Contact your service provider directly if you have questions about curbside recycling services for plastic products:

Alameda County Industries
(510) 357-7282
They offer Recycling How To’s under the Customer Center tab

Waste Management of Alameda County
(510) 613-8710

Find other opportunities for plastic recycling using the Recycling Guide at http://www.stopwaste.org/