Hi CeruleanBlue,
Without wool it would have to use another method to pass the regulations. IMO … the best option in this case would be a viscose/silica inherent material which is also non toxic (see post #2 here). With a prescription from a health practitioner … you can also have a mattress made without any fire retardant barrier at all.
The regulations in Canada are different and not as stringent as the US but there are still regulations and Canadian mattresses are often made the same as their US counterparts so it would have some form of fire retardant as well. Each manufacturer can provide more specific details about their mattress.
Phoenix