I’ve seen a lot of discussion on the benefits and concerns regarding using puppy pads as liners in your rat cage, and decided to do some research to find the facts.
So what’s the debate? Advocates of puppy pad liners are using the sheets in their rat cages, usually under a layer of fleece, and cite benefits such as added absorbency, reduced smell, easy cleanup, and low cost. Opponents of puppy pad liners cite concerns such as the environmental impact of adding plastic to landfills, and the potential for your rats to ingest the absorbent polymers if they are chewers.
The main ingredient of concern are the “super absorbent polymers” (or SAPs); this is the same type of stuff found in disposable diapers due to its ability to absorb (and not release) moisture.
I did some research to address the potential toxicity of SAPs, and found the following information:
- Ingested SAPs – Material Safety Data Sheet (http://www.cooltiesareus.com/crystal_specs.html). The MSDS sheet showed that SAPs have been tested on rats (sorry, awful I know), and have been found non-toxic through oral consumption at: LD50/oral/rat > 5000 mg/kg.
- Inhaled SAPs – Material Safety Data Sheet (http://datasheets.scbt.com/sc-255432.pdf). This MSDS sheet showed the following rather serious implications:
“A two year oncogenicity study with high molecular weight polyacrylate (1 million), with no reactive functional groups, showed a statistically significant induction of lung tumours in rats exposed at 0.8 mg/m3 respirable particles.”
“Various lung effects such as inflammation, hyperplasia (abnormal increase in the number of cells composing a tissue or organ), scarring (fibrosis), changes in the air sac (alveolar) ducts of the lung, and tumours were noted in laboratory studies with rodents inhaling concentrations of water-absorbent sodium polyacrylate dusts greater than 0.05 mg/m3 (respirable particles) for the majority of their lives.
Furthermore, some lung or lung cell effects were found in rodent laboratory studies of shorter duration.”
The primary concern appears to be inhalation of the SAPs; ingestion would be a secondary concern. Of course, inhalation and ingestion are closely related because if your rats are chewing puppy pad liners, there’s a good chance they are inhaling as well as ingesting the polymers.
Clearly, puppy pad liners are not a good idea if you have rats prone to chewing. However, if your rats are a little more relaxed, you can probably give them a try and see how well they work in your cages.
I definitely do not recommend having the puppy pads as the only form of liner due to potential inhalation of the SAPs; however, covering the liners with fleece as many people do should provide enough of a barrier to prevent inhalation of any particles.
What are your thoughts? Have you ever tried puppy pad liners in your pet rat cages?