It is important to remember when choosing any children's bedding, including Dora the Explorer comforters, that parents check the label for filling content, hypoallergenic properties, and to see if the material is flame retardant.
The other option, organic wool, is an excellent flame retardant as well as being organic if there has been nothing added to it. If you see wool on the material list, you may want to verify that it is indeed organic wool.
The argument against fire retardant chemcals states that more people will develop cancer, lung problems and other health issues related to toxins in the mattresses than will die from the mattress catching on fire.
Cellulose: Constructed out of old newspapers that have been shredded into tiny pieces and treated with a fire retardant, most cellulose insulation is installed by a professional.
Manufacturers treat it with a number of fire retardant chemicals that are considered effective and safe, however, like sodium borate, boric acid, and ammonium sulfate.