Did you know that up market nappies contain polymer balls? They exploit the water absorbing qualities in order to absorb urine. These are made from a similar polymer to water beads and are the chemical that is used to make fake snow. This polymer is also used for its water absorbing properties in gel flood bags to contain a flow of water.
I had thought to allow the children these to play with (the balls not the nappies). There are many article expounding on the dangers of this. And I read a few. I also looked at the chemistry and the research (which stated they were safe, and it was only prolonged exposure inhaling it that there could be dangers). I decided that as long as a few precautions were taken they should be perfectly safe.
- The powder would not be breathed in as I would do the handling of the dry powder inside a ziplock bag. Once water was added this would cease to be an issue.
- The powder would not come in contact with the skin at all, as the children would be wearing protective equipment
- I would teach them about the potential dangers of handling this chemical and how to minimise them
I emptied two nappies, shook out the balls, all within the confines of a ziplock, removed the bulky material, and was left with 4 tsp of tiny white balls. I placed 1/2 tsp into their test tubes and instructed them not to touch. They were given gloves, and as always wore their goggles. As they were going to immediately add water and would not be in contact at all with the powder, I felt they were safe without any face mask. I let each child add some coloured water and stir, and explore for as long as it held their interest.
Their tray was set with goggles, gloves (and elastic bands to keep them on), large test tube with polymer powder in, small test tube with coloured water, pipette and something to stir with:
The older children joined in. They had loved the water beads so I asked them to think of another use for them other than just to water plants. The night before I had rehydrated some of the nappy polymer and they had commented that it looked like snow, so T11 said to make fake snow. Nobody guessed that they were used in nappies or to prevent flood water. I asked them to put a teaspoon of polymer powder into a pot and then to record how many teaspoons of water it would take to liquefy. They set up their trays something like this:
So the polymer powder in the nappies took in 100 times their own volume before they became even slightly wet! I asked the children what the advantages and the disadvantages were of the polymer being used in nappies. T11 commented about the bulk when the polymer expanded, L10 made the comment about urine being left near to the skin, C10 said the nappies wouldn’t leak and would need to be changed less frequently. I asked if this was an advantage or disadvantage. They discussed it and came to the conclusion it would be an advantage for the parents but maybe not for the baby. I also had them consider the potential dangers for the baby. We discussed the use of a one way semi permeable membrane built into the nappy, protecting the baby’s skin. Also I told them what I had learnt when I took the nappy apart- that the balls were in the back of the nappy with a wad of cotton next to the baby’s bottom.
Interestingly, it was the expensive brands which contained the most polymer powder, whereas the cheap brands had hardly any at all. I learn something new everyday!