Eco bricks are a proposed solution to dealing with single-use plastics by compacting them into dense bricks. The document discusses pros and cons of single-use plastics, alternatives to them like eco bricks, and how to make eco bricks by collecting plastic waste and compacting it into bottles to meet a target density specification. It also explores using eco bricks to potentially help solve Scotland's plastic waste problems by removing plastic from the waste stream and environment.

1. Eco bricks

3. Single use plastics are any disposable plastic item
which is made to be used only once.
Can you think of
some items that are
single use plastic?

4. Think back to the last
item of single use
plastic you came
across?
What did you do with
it when you were
finished using it?

5. Amazing stuff?
• Pros
• Cons
• Pros
• Cons

6. Amazing stuff?
What are some pros and cons to single use plastic?
Pros:
• convenient
• Lightweight – imagine if you had to carry all the water you use
• Durable-items don’t break or fall apart easily
• Cheap to make and buy
Cons:
• Can be easily carried away by wind and easily litter the planet
• Doesn’t break down or biodegrade easily or at all
• Animals can ingest or get tangled in it
• Cheap so it is easy to just make more after it is thrown away

7. What are some alternative to single use plastic?

8. Over the past week and
a half I collected all the
plastic that I would
normally throw in the
bin.
This plastic accounts for
two people in a
household.

9. Waste ‘R’ Us charges for their waste collection services. They use the following formula to
calculate the cost, C in pence, given the waste, W, in grams.
C = 0.5W + 4000
 Estimate how much will my 175g of plastic waste cost if I use Waste ‘R’ Us?
 Calculate the cost of my 175g
The 4000 in the formula is the callout charge to collect the waste.
 How much would it cost me per year if I could store all my waste for a single collection?
 What assumptions did you have to make in finding an annual cost?

11. What can we do
about the plastic that
we cannot recycle?

12. One solution is Ecobricks
Find our more in this
short film

13. Ecobricks are one of the few
ways to effectively sequester
single use plastic. Ecobricks
remove plastic from the
biosphere and from the
industrial recycling system.
Ecobricks raise ecological
consciousness and enable
individuals, communities and
companies to transition from
plastic.
https://www.ecobricks.org/why

15. Changing the specification
Ecobricks4Life is looking for donations.
They require that each bottle has a density of 0.4 g/ml.
 How many grams of plastic should there be in each ml of a bottle?
 How many grams of plastic should a 100ml bottle contain?
 How much should every 10ml of an Ecobricks4Life
bottle weigh??
What is the target weight for a 330ml bottle?

16. Working with a formula
Ecobrick density specifications vary between 0.33 and 0.7 g/ml.
A formula is useful for finding weights of ecobottles
- if the calculations are to be done with a spreadsheet
- if the specification changes frequently
- If the specification is given to many decimal places
The formula for density (given by the Greek letter rho 𝜌) is 𝜌 =
𝑚
𝑉

17. Homework: How much single use plastic do
you use in a week?
• In your jotters write down an estimate of how many grams of single use plastic
you use in a week.
• Over the next week collect all the plastic you would normally throw into the bin
and either weigh it at home and bring in a selfie with it or bring it into class and
we can weigh it here.
• Next week we will measure and compare our results as a class.
• Extension: Make an ecobrick! (this may take you more than a week) Remember
each brick needs to have a density of 0.3g/ml. Collect a plastic bottle and
calculate the weight of single use plastic you would need to collect.

18. Homework follow up
Plastic Estimate: _________ Actual Plastic:__________
How close were you to your estimate?
How many eco bricks could you make from your single use waste?
What strategies could you try to help you reduce your waste?

19. Homework follow up
Come up and write your plastic weight in grams on the board
The formula to calculate the average plastic waste per person is as
follows:
𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑝𝑙𝑎𝑠𝑡𝑖𝑐 𝑤𝑎𝑠𝑡𝑒 =
𝑆𝑢𝑚 𝑜𝑓 𝑝𝑙𝑎𝑠𝑡𝑖𝑐 𝑖𝑛 𝑔𝑟𝑎𝑚𝑠
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑒𝑜𝑝𝑙𝑒
When we find the mean average we are sharing the total pile of waste
out equally between ourselves.

20. Could ecobricks be
a solution to
Scotland’s plastic
waste?
Read all about it in
this news article

21. • War on Plastic with Hugh and Anita
https://www.bbc.co.uk/programmes/m0005xh7
• Newsround article
https://www.bbc.co.uk/newsround/42810179
• BBC article ‘what’s the real price of getting rid of plastic packaging?’
https://www.bbc.com/worklife/article/20180705-whats-the-real-price-of-
getting-rid-of-plastic-packaging