Measuring Compostability in Bioplastics

On Friday, September 4th, 2020 the Sustainable  Systems Research Foundation Team in collaboration with Hard Core Compost initiated a bioplastic experiment at their compost facilities located on Shaffer Rd in Santa Cruz. The purpose of this experiment is to verify the compostability of certain bioplastic products. We are currently developing for our SPIN Project a catalog of single-use foodservice compostable products that will allow local restaurants to order compostable supplies from the right vendors. We have collected bioplastic sample products from various companies around the world to work on this bioplastic experiment.

We divided the sample products that we have collected into four containers and we buried them on composting piles to see how long it takes for these bioplastic sample products to decompose. We are also measuring temperature on the soil in order to record their compostability under home compostable conditions. The contents of the four containers are below:

First Container:

The products in the first container: (Control Container)

3 Plastic spoon

4 Plastic straws

3 Plastic forks

1 Produce bag

1 Plastic cup

Second Container:

The products in the second container:

4 Thin Sugar cane straws

6 Thick sugar cane straws

5 Coffee grounds straws

1 Bagasse spoon

1 Bagasse fork

1 Bagasse knife

1 Sugar cane bagasse fork

1 Sugar cane bagasse knife

1 Sugar cane bagasse spoon

1 Coffee grounds spork

1 Green tea spork

1 Sugar cane spoon + white additive

1 Sugar cane fork + white additive

1 Sugar cane knife + white additive

Third Container:

The products in the third container:

2 Compostable plates

1 Compostable garbage bag

2 Compostable forks

2 Compostable knifes

2 Compostable spoons

Fourth Container:

The products in the fourth container:

2 Compostable films

Temperature sensor in our compost pile.

Compost pile at Hard Core Compost.


On Friday, October 2, 2020, the Sustainable Systems Research Foundation Team visited The Hard Core Compost site to check on the decomposition process for the bioplastics sample products after a month in the compost pile. Below are the results after our first visit:

First Container


Temperatures for the first container .

The products of the first container after a month in the composting pile.

This container is our control in the experiment and we expect no change in the products. As expected the plastic materials did not decompose.

The silver plastic forks had a change in color.

Second Container


Temperatures for the second container

The products in the second container after a month in the composting pile.

Thin straws are splitting at the ends. The thick straws are flattened and splitting in the middle.

All cutlery is getting quite thin and is easily breakable.

Third Container


Temperatures for the third container

Products in the third container after a month in the composting pile. Cutlery has not changed.

The garbage bag became very thin. Plates have lost their shape. They are very thin and their thick texture is gone.

Fourth Container


Temperatures for the fourth container

Products in the fourth container after a month in the composting pile.

The clear bag is very thin. The closure of the clear bag has split and the lettering on the bag is coming off.

The white bag has a yellow coloration and is very thin.The white bag still feels pretty firm to the touch .

This Post Has One Comment

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