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The City of Portland, Oregon

Sustainability at Work

Providing free tools and expertise to achieve your goals

Phone: 503-823-7037


Composting at work: It's different than at home

business compost goes to a biodigester and creates energy

Did you know that your compost bins at home and work have different guidelines? They go to different processing facilities and have different rules about what's allowed.

Business compost makes energy. The food scraps collected at Portland businesses (restaurants, offices and more) go to a facility that turns them into energy.

How it works

Food waste is blended into a liquid and is broken down by bacteria. The bacteria create methane, which is captured and burned to make electricity. The leftover materials are used as fertilizer to enrich soils.

Food gets picked up and taken to biodigester facility

This 1-minute video from across the pond shows how an anaerobic digestion facility turns food waste into energy.  

It's food only

Food is the only thing allowed in business compost, with the exceptions of BPI-certified compostable bags, used paper coffee filters and tea bags. Non-food materials gum up the system and have to be filtered out. See examples of what's allowed and print posters for your workplace.

Things you should NOT compost at work

Items not allowed in compost

While the following items are allowed in your green bin at home, they should not go in compost bins at Portland businesses:

  1. pizza boxes
  2. napkins, paper towels
  3. yard debris, flowers*

Also, to-go containers, cups and utensils are never allowed in compost, at home or at work. This applies to all types of containers, even those labeled "compostable" or "biodegradable." They should always go in the trash. 

*Wondering why flowers aren't allowed? The stems are tough and woody, which makes them difficult for the microbes to break down.

Want to start composting at work?

We've got getting started guides for restaurants and offices, or contact us for help. 

Find more detailed information: