All UK beds must have a fire retardant layer or component, whether it is contained within the foam mix, sprayed on afterwards, mixed via graphite in Latex or a fire retardant cover i.e. wool or synthetic. It’s important that as a consumer you are aware of the regulations around fire retardants.
This is to comply with British regulations (BS 5852: 1982 Part II & BS 7177). Mattresses from other countries may have different compliance levels or in some cases no compliance. It is important when you purchase a mattress you are aware of this.
In the case of mattress covers, they must be compliant with BS 7177 low hazard for domestic use. This is to ensure that the covers of the mattresses are fire resistant to a cigarette or smoulder test.