Can I compost nappies in the HOTBIN?

Thursday, 21 March 2013  |  HOTBIN Composting

In the HOTBIN you can compost disposal, biodegradable nappies (diapers) - both soiled and wet/soiled.

Below is our case study on tests to compost the g-nappy pad - these are easy and straight forward to compost in the HOTBIN.

Note: in the case study, we describe the difference between the g-nappy (g-diapers in USA) 'pad and pant' system versus the more common disposable nappy systems which use biodegradable plastics to cover the pad. These biodegradable covers compost slowly, and will create problems UNLESS you shred the plastic to allow air into the pad. The industrial compost sites use big shredders for this task - at home you might not want to cut and shred a plastic liner on a soiled nappy! 

Gmums Hints and tips for using the HOTBIN

The HOTBIN is an effective composing & recycling solution for g-nappy pads. The HOTBIN rapidly breaks down gNappies when hot composting at 40-60°c. The nappy pads are substantially broken down within 14 days and completely with 90 days.

You will find NO odour issues when the lid is closed - even if you compost soiled nappies!

Tips for gMums wanting to use the HOTBIN

  • Get your HOTBIN hot before adding nappies
The HOTBIN is unlike traditional cold composting bins. We advise you to use it for 3 months, get it hot, ie working at 40-60°c before adding gNappies. This ensures you know how it works and experience the filling routines for keeping it hot. Expert users can get the HOTBIN hot with nappies in an empty bin – but if it goes wrong, cleaning out half composted nappies will not be fun. New mums and dads have enough on their plate with the new baby so get the HOTBIN working before the nappies start arriving.
 
Everything you need to know about getting your HOTBIN up and running are in the instruction manual sent with the HOTBIN. There is extensive help on our Support Pages.
  • Add one handful (about 30g) of cardboard box pieces or shredded office paper per 4 nappies added.
  • NEVER forget to sprinkle on the ‘bulking agent’.
(The composted wood chips (bulking agent) are essential – the nappy contains paper pulp and it will collapse into a wet mushy layer that will block essential airflow. The wood chips (added at rate of 1 handful per 4 nappies) maintains the airflow; ensure high temperature, fast composting and low odour
  • Avoid adding plastic bags (even a compostable plastic bag).
It is common to ‘bag’ each nappy into a plastic bag straight away. You can’t add nappies into the HOTBIN bagged – the bags prevent airflow and hence effective composting. We found it easier to collect them in a plastic bucket (lined with a bigger bag) and then just tip the nappies in and replace the big bag each week with a fresh one.
  • Add your nappies every 2-3 days and empty your compost pail at the same time
The temptation will be to take nappies out to the HOTBIN every time you change baby. This means the HOTBIN could be opened 6-8 times a day, and each time it loses heat – it won’t work effectively, open every other day. We found it easier to use a bucket/lid and collect 2-3 days worth then add in one go – don’t forget to mix in bulking agent.  With a bit of trial and error you’ll find a routine that works for you and the HOTBIN!
 
If you split the nappy with a sharp knife, they will compost faster.
(This is not essential and for certain nappies might be undesirable, but it is worth knowing the rayon cover sheet is slower to compost than the paper pulp inside. If you slit the cloth, the contents inside breakdown faster. This might be useful to know if you have a lot of nappies and you find the HOTBIN is filling up too fast!)
  • The HOTBIN is going to fill up – if you have twins, two toddlers or generally more than 8 nappies a day, give us a ring and discuss – it also depends on what other compost waste you have, but you might need two  HOTBINs
  • Use the HOTBIN per the user manual, adding garden, food, cooked food and grass waste as an when

What happens to the different materials in the gNappy?

  • The white fluffy pad is made from paper pulp. This is cellulose fibre, the same cellulose that all plants are made from and bacteria eat as their core diet.
  • The super absorbent polymer is also broken down by bacteria
  • The porous top sheet covering the inner side of the gNappy is a biodegradable rayon cloth. (Rayon is a modified polymer created from natural cellulose fibre).

Is home composting nappies with faeces safe?

You can opt to compost wet nappies or both wet and soiled nappies

We believe it is safe to compost soiled nappies.

The scientific evidence on pathogen destruction is well documented and robust. We can therefore infer destruction rates and safety based on the 40-60°c time temperature profile achieved in the compost pile.
 
Any mother who composts nappies from their own children has already been exposed to the massively higher risk of contamination by changing the nappy and cleaning the baby!