Abstract: The present invention provides a polyolefin resin foam sheet having an area density of 5 g/m2 or more and 400 g/m2 or less, and having a time (t) required for a weight decrease from 90% by mass to 10% by mass, of 9 minutes or more, as measured by thermogravimetric analysis carried out at a heating rate of 10° C./min and a measurement temperature of 23° C. to 550° C. According to the present invention, a polyolefin resin foam sheet can be provided that has a high fire retardancy while maintaining a lightweight property.

Abstract: A flame retardant resin composition includes a polyolefin resin, a phosphate compound, and an organic phosphorus compound. The phosphate compound includes a salt of a phosphoric acid represented by the following formula: where m represents an integer of 1 to 100, and an amine compound containing an amino group in a molecule, and the organic phosphoric compound (C) is represented by the following formula: where X1 and X2 are the same or different, and are represented by the following formula: ALAr)n??(3), where AL is a branched or linear aliphatic hydrocarbon group having 1 to 5 carbon atoms, Ar is a phenyl group, a naphthyl group or an anthryl group which may include a substituted group, and bonds with an optional carbon atom in the AL, and n indicates an integer of 1 to 3.