# Is the absorbent substance in nappies biodegradable?

I am looking to use the absorbent material found in nappies to improve the water retention of the soil in my garden.

1. Are disposable nappies made with Sodium or Potassium Polyacrylate?

This class of polymer is also referred to as superabsorbent polymer(SAP).

1. Disposable diapers/nappies are likely to be the sodium form. Sodium forms are typically cheaper. Further, the potassium form of the salt is not as soft and would be less suitable for cloth-like wearables.

2. Polyacrylate SAP does not biodegrade in soil very fast.
For the main chain polymer:

...if at all, 0.12-0.24 % per 6 months.

2: Wilske, B.; Bai, M.; Lindenstruth, B.; Bach, M.; Rezaie, Z.; Frede, H.-G.; Breuer, L. Biodegradability of a polyacrylate superabsorbent in agricultural soil. Environmental Science and Pollution Research 2013, 21 (16), 9453–9460.Springer

Side note: All diapers with an absorbent layer are SAP, either polyacrylate or polysaccharide (rarely). Polysaccharide is the more expensive / less effective 'green' alternative, and if your product contains this, it will tout it on the label. (link limit reached)

babygearlab.com/a/11113/What-Is-Inside-Those-Disposable-Diapers
https://blog.bolandbol.com/product-reviews/diapers-review/

• This is little more than a link-only answer. Since links to the www could theoretically decay quickly, this site’s policy is to include (i.e. quote, using >  at the beginning of lines) the essential information here but leave the link as a citation. Please edit to do so or this posting may be eligible for removal. – Jan Mar 29 '17 at 14:59