Question
I wanted to know if these Palm plants are toxic to humans if ingested?

Answer
Hi Barbara,
   Cataractarum Palms (also commonly known as Cat Palms), as well as most other types of palms, are not listed anywhere as being poisonous. However that does not mean that it is 'safe' to ingest any part of the plant.

Any plant can cause harm, especially to children and animals, if chewed or ingested. No matter if it is considered poisonous or not. Even plants that are listed as 'safe' nonpoisonous plants can cause stomach upset, skin rash, lip/tongue swelling or could cause a potentially fatal allergic reaction. Especially in young children, puppies and/or kittens.
It is always best to keep all houseplants in a place out of reach of children and pets.

When trying to determine what plants are known to be poisonous, looking up a specific plant online or in other botanical sources can often be of little help. Some websites and sources will say that a plant is poisonous while other websites/sources will say that it is not poisonous.

While there is no definite tell tail signs that a plant is poisonous, there are a few standard signs that can help you identify potentially poisonous plants.
The signs for possible poisonous plants are:

Milky Sap
Naturally shiny leaves
Plants that have yellow or white berries
Umbrella shaped plants

I hope this helps. If you have any questions or need additional information please don't hesitate to ask.
     Thanks
       Tracy