Wait... Can I Recycle This?

The surprising reasons behind everyday recycling rules in Knoxville, TN.

You may put your recycling in a brown curbside bin, take it to a city recycling drop-off center, or take it to a county convenience center. Recycling isn’t always intuitive, and rules can change at each county, town, or state. Something can be technically recyclable but not accepted locally because of contamination, sorting equipment, the market for recyclable materials, or how the materials are processed. Here are some common questions that Knoxville recyclers ask.

10 Recycling Questions Answered

Paperboard vs Corrugated Cardboard. Source: Agreen Packaging

  1. Paperboard vs. Cardboard: What’s the Difference?

  • Paper = thinner, flexible materials like printer paper, newspapers, or magazines. This goes in the paper recycling.

  • Paperboard = thin, lightweight boxes such as cereal boxes, cracker boxes, or tissue boxes. This goes in the paper recycling.

  • Corrugated Cardboard = thick, rigid material with a grooved wavy pattern between two flat sheets, mainly used for shipping boxes. This goes in the cardboard recycling.

2. Can I Recycle Pizza Boxes?

Mya shoveling pizza out of recycling. Source: KKB.

A common misconception is that pizza boxes aren’t recyclable; however, in Knoxville, they are!

  • Put your empty pizza box in the cardboard recycling bin. Remove leftover pizza, dipping cups, utensils, and napkins.

  • A little grease doesn’t make the box trash; however, if your cardboard is heavily food-soiled or wet, it isn't recyclable.

  • If it’s too soaked to recycle, try composting the cardboard!

3. Why Isn’t Glass Accepted in My Curbside Bin?

  • Glass bottles and jars are highly recyclable and can be taken to the City of Knoxville Recycling Drop-Off Centers!

  • Make sure to remove steel lids and corks before recycling.

  • But glass isn’t accepted in curbside bins because it can break during collection and contaminate other recyclable materials.

  • Broken glass can also create safety issues for workers and damage equipment.

  • Try reusing your glass jars and bottles as a vase, a food container, a craft, and more!

4. Why Is Glass Sorted by Color?

When you visit a recycling center, you will notice glass is sorted by three colors: clear, green, and brown.

  • Sorting glass by color at recycling drop-off centers helps manufacturers so they can collect certain colors and easily melt them back down into the color of glass bottle they would like.

  • Can I put other colors in the bins besides clear, green, and brown? Of course! Just put it in the bin that is closest to that color, so blue would go in the green bin and red would go in the brown bin, etc.

  • The recycling centers in Knoxville only accept glass jars and bottles, so no window glass, mirrors, picture frames, etc.

5. Why Can’t Plastic Bags Go in the Recycling Bin?

Clear glass bin at recycling center. Source: KKB

Plastic bags and plastic film are not accepted in Knoxville’s curbside or center recycling because they can:

  • Wrap around sorting machinery

  • Jam equipment

  • Interrupt the sorting process

  • Create safety and maintenance problems

  • Often contain trash, food, and other contaminants

However, you can recycle plastic grocery bags at many grocery stores or at the UT Public Recycling Drop-Off Center. Also, if you store your recyclables in plastic grocery bags or trash bags, make sure to dump them out of the bag at the recycling center!

6. Why Are Only #1 and #2 Plastics Accepted?

PETE and HDPE. Source: Guide of Greece


If you look at the bottom of a plastic bottle or container, you will see a recycling triangle; however, that doesn’t always mean it is recyclable. The number inside the recycling symbol tells you what kind of plastic it is, not whether your recycling program accepts it. In Knoxville, only #1 plastics and #2 plastics are accepted in curbside bins and at the recycling centers. Around the world, these two types of plastics are more widely accepted for recycling due to their properties and market demand.

  • Plastics #1 = PET/PETE

    • Clear and transparent

    • Smooth and glossy

    • Used for beverage bottles

  • Plastics #2 = HDPE

    • Opaque, cloudy, or colored

    • Stiff and rigid

    • Used for milk jugs, shampoo bottles, and laundry detergent

Plastics #5 used to be accepted in Knoxville, but it is no longer accepted due to the change in the market. They are commonly used for yogurt cups and other food containers, so watch out for #5s when recycling! This could change in the future, so stay up to date on recycling rules for your area.

7. Styrofoam: What is it?

  • Styrofoam is considered #6 plastic, polystyrene.

  • It’s used for packing peanuts, coffee cups, and food containers.

  • It is not accepted in any of the Knoxville recycling bins. However, packaging peanuts can be taken to some package stores, and food containers can be dropped off at Publix.

  • We recommend limiting your usage of Styrofoam when possible. Use reusable takeout containers and coffee cups instead.

  • Don’t forget to take Styrofoam out of your cardboard boxes before putting them in the recycling!

Aluminum can bin at recycling center. Source: KKB

8. Does This Go in the Aluminum or Steel Bin?

When you recycle metals at the recycling center, you may not think it matters whether it goes in the aluminum or steel bin, but it does!

  • Aluminum

    • Lightweight

    • Used for soda and beer cans

    • Can be recycled immediately without losing essential properties

    • A magnet will not stick to it

  • Steel

    • Heavier and stronger

    • Used for soup, vegetable cans, and other food cans

    • Often coated with a thin layer of tin to protect it

    • A magnet will stick to steel

  • Metals That Cannot Go in the Metals Bin

9. Cap or No Cap?

  • Plastic Caps

    • Keep the cap on plastic bottles so it can be recycled and won’t get lost in the sorting process.

  • Steel Lids

    • Take the steel lids off glass jars and bottles and place them in the steel bin.

  • Corks

    • Take corks out of glass bottles and place them in the trash or compost if they are natural wood material.

10. Are the items actually recycled?

YES! According to the City of Knoxville Waste and Resources, once the valuable recyclable materials from your bin are sorted and baled at Smurfit WestRock, they are sold to various regional manufacturers in the following locations who recycle them into new products.

  • Knoxville, TN: Steel Cans, Aluminum, and Scrap Metal

  • Cowpens, SC: Cardboard

  • Stevenson, AL: Cardboard and Mixed Paper

  • Seminole, FL: Mixed Paper

  • Troy, AL: Number 2 Plastic Containers (HDPE)

  • Atlanta, GA: Sorted Glass (from recycling drop-off centers)

  • Charlotte, NC: Steel Cans

  • Chatsworth, GA: Number 1 Plastic Containers (PET)

  • Chicago, IL: Steel and Aluminum Cans (only every now and then when needed)

The Golden Rule of Recycling

When in Doubt, check it out. Recyclable doesn’t always mean recyclable in Knoxville.

Knoxville Recycling Poster. Source: City of Knoxville

For more information, visit the City of Knoxville, Knox County, and UT Public recycling websites. For more recycling FAQs, visit the KKB website.

Mya Moseley