Abstract: A self-extinguishing polymer composition consisting of 20 to 70% by weight of thermoplastic resin or elastomer (A), 80 to 30% by weight of a hydroxide of aluminum and/or magnesium (B), and a polymeric charge-transfer type complex (C) in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of (A) and (B).

Abstract: As a fuel oil additive, an ethylenic copolymer is provided which is derived from:(a) ethylene, and(b) at least one monomer selected from the group consisting of vinyl esters of saturated carboxylic acids, ethylenically unsaturated mono- or di-carboxylic acids and esters thereof which are represented by the general formula: ##STR1## wherein R.sup.1 represents hydrogen or a methyl group, R.sup.2 represents the group --OCOR.sup.4 or --COOR.sup.4 in which R.sup.4 represents hydrogen or an alkyl group having 1 to 18 carbon atoms, and R.sup.3 represents hydrogen or the group --COOR.sup.4 in which R.sup.4 has the same significance as above, having a number average molecular weight of less than 1,000 and a (b) component content of 1 to 25 mol %, and containing 2 to 10 alkyl branches per 100 methylene groups. Addition of the copolymer to a fuel oil provides a modified fuel oil having improved plugging resistance and having improved flowability.