Striving for Sustainability

Punahou Food Services partners with a company called World Centric to obtain its “compostable” products used to feed our campus community: cups, cutlery (fork, knife and spoon), and salad containers.
Reducing Waste at Lunchtime
The Food Services department began an inquiry into how they could reduce the amount of self-serve products being purchased, and how those items could be recycled after use. In Kindergarten – grade 5, rather than one-time use materials, the transition to washable plates and silverware was made. This reduced our self-service products by about 35% in our younger grades.
In grades 6 – 12, the transition to washable plates and silverware was not as simple given those grades do not have a set lunch hour, and all students do not go to the Cafeteria at a set time for lunch. This also increased the possibility that silverware and trays may not always be returned to the Cafeteria if students ate lunch elsewhere on campus. For these reasons, grades 6 – 12 continued using self-service items, so it was important that waste was minimized, and the products were ecofriendly.
World Centric compostable plastic cups and containers are made from a bio-based plastic derived from renewable plants. Chemically, this material is known as PLA or Poly Lactic Acid, which can be derived from a variety of plant-based starches.

Punahou also uses the soup bowls and paper plates from World Centric which are certified compostable in a commercial composting bin. The soup bowls are made of paper with a bio liner made of plant material so the hot liquids can be held in the bowls without the bowl absorbing the liquid and collapsing.

History of Composting
Commercial composting, as we know it today, got its kick start in the 80s and 90s when many states mandated that yard waste (known as green waste) be composted. Commercial composting sites were developed in conjunction with landfills. What started as a way to compost green waste has expanded in some areas to include pre-consumer food scraps, post-consumer food waste, compostable fiber products and compostable plastics.

Limitations of Composting
  • Most compost facilities only accept green waste because this is what these facilities are mandated to take by state government. Expansion into other materials beyond green waste requires improvement in the facilities equipment and infrastructure.
  • Home composting bins do not break down the compostable plastics and fibers as they are unable to achieve the higher temperatures it takes to break these items down.
  • An item that is compostable is one that is made entirely from carbon-based biomaterials like leaves, wood, plant fibers and so forth. Compostable items must be able to be broken down completely by microorganisms within a limited amount of time and should not leave behind any toxic residue or chemicals.

Biodegradability and Compostability
by Lauren Olsen Zero Waste Manager at World Centric

Compostable Plastic
A material capable of undergoing biological decomposition in a compost site as part of an available program, such that the plastic is not visually distinguishable and breaks down to carbon dioxide, water, inorganic compounds, and bio mass, at a rate consistent with known compostable materials (e.g. cellulose) and leaves no toxic residue.
In order for a plastic to be called compostable, three criteria* need to be met:
  • Biodegrade – break down into carbon dioxide, water, biomass at the same rate as cellulose (paper)
  • Disintegrate – the material is indistinguishable in the compost, that it is not visible and needs to be screened out.
  • Eco toxicity – the biodegradation does not produce any toxic material and the compost can support plant growth.
*From American Society for Testing and Materials (ASTM).
Biodegradable Plastic
Plastic which will degrade from the action of naturally occurring microorganism, such as bacteria, fungi etc. over a period of time. Note, that there is no requirement for leaving “no toxic residue, and as well no requirement for the time it needs to take to biodegrade.
Degradable Plastic
Plastic which will undergo a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties. Please note that the is no requirement that the plastic has to be degrade from the action of “naturally occurring microorganism” or any of the other criteria required for compostable plastic.
A plastic therefore may be degradable but not biodegradable or it may be biodegradable but not compostable (that is it breaks down too slow to be called compostable or leaves toxic residue).
Composting in Hawai‘i
Here in Hawai‘i we do not have a composting facility. We have a landfill that mostly takes construction material. H-power is where Punahou’s waste goes, H-power burns mostly green waste, pre-consumer food scraps, post-consumer food waste, compostable fiber products and compostable plastics by burning it and converting into energy.

“Punahou’s Food Service Department has been striving to be a more sustainable entity of Punahou since 2007. This was one year after former President Jim Scott ’70 set out his 10-year plan for Punahou’s sustainability initiatives. As soon as the initiatives came out, we started looking at what we were doing and the products we were using.”

Marcia Barrett ’74 Wright, Food Services Director

According to the EPA, over 26 million tons of petroleum-based plastic ends up in U.S. landfills alone each year.

With human activity testing the limits of our planet’s bio-capacity, we need to find better ways to tread lightly. Choosing eco-friendly products is one way to aid our ailing environment, so we created World Centric to provide you with plant based, sustainably made products that are designed to transform into healthy, new soil through composting.
The mission of World Centric is to reduce waste in people’s everyday lives so they encourage everyone to think hard before buying any single-use disposable products, even compostable ones, and always “reduce, reuse and recycle.”

Benefits to using World Centric products:
  • Made from plants instead of petrochemicals from fossil fuels
  • Manufacturing uses less energy and creates fewer greenhouse gas emissions
  • Freezer safe
  • Certified to break down in a commercial composting facility in 3 – 6 months
Limitations of World Centric products:
  • May be mistaken for traditional plastic by consumers
  • Cannot handle hot foods or liquids
  • Needs to be stored at temperatures below 110 away from hot surfaces and direct sunlight
  • Not suitable for home composting
  • Not accepted by many commercial composting facilities.
H-POWER is the cornerstone of Honolulu’s integrated waste management system. H-POWER produces up to 10% of O‘ahu’s electricity and reduces the volume of refuse going to landfill by 90%. On O‘ahu, waste-to-energy works in partnership with recycling efforts to significantly reduce the amount of waste going to landfills.

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