How do you dispose of those Cool Packs for sports injuries?

Does anyone know whether there is an environmentally friendly way to dispose of the cool packs such as the HypaCool Instant Cold Pack by SFA Group Ltd.?

I have two and I don't know what to do with them. I have no idea what is in them so I don't know if I can pour the contents away and recycle the plastic. I'm fed up with seeing them in my little pile of things I don't know what to do with that accumulates on my kitchen windowsill so today I've emailed the company that supplies them.  In the meantime please do let me know if you can tell me what is in these packs and how to dispose of them safely.

Thanks!