The invention comprises hydroxyphenyl-1,3,5-triazines of the formula <FORM:1065425/C2/1> where R represents a hydroxybenzene residue which contains in the o-position to the triazine ring a hydroxyl group and in the p-position a residue of formula <FORM:1065425/C2/2> where D represents an organic residue and N = 1 or 2, A represents a benzene residue and X a halogen atom or benzene residue, which are prepared by the reaction of 21,41-dihydroxyphenyl-triazine compounds in the presence of a tert-amine and, if desired, an inert organic solvent, with an isocyanate D-N = C = O or an acid halide <FORM:1065425/C2/3> or an acid anhydride D-C = O > O D-C = O and many examples are given. The compounds are used for protecting organic materials from the effects of heat, air, and ultra-violet rays. Particularly valuable compounds are those in which R represents a residue <FORM:1065425/C2/4> in which n = 2 or especially 1, and D1 stands for an alkyl (1-18 C) or benzene residue which maybe substituted by halogen, hydroxyl, alkyl (1-4 C), alkoxy (up to 8 C); A1 the residue above or <FORM:1065425/C2/5> The compounds of formula <FORM:1065425/C2/6> are of especial value and examples of the preparation and use are given.ALSO:Stabilizers against heat, air, and especially ultra-violet light, comprise hydroxyphenyl-1,3,5-triazines of formula <FORM:1065425/C3/1> where R represents a hydroxybenzene residue with a hydroxy group in the ortho position to the triazine, and in the para position a residue <FORM:1065425/C3/2> where D represents an organic residue and n = 1 or 2, A represents a benzene residue and X a halogen atom or a benzene residue (see Division C2), and are used to protect polymers and copolymers such as polyethylene, polypropylene polyvinyl chloride, polyacrylonitrile, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymers, polystyrene, polychloroprene, polysulphides, polybutadiene, copolymers of butadiene and styrene, and butadiene-acrylonitrile, polyesters, and polyamides, alkyd lacquers, epoxy resins, phenol-, urea- and melamine-formaldehyde resins, natural rubber, and cellulose derivatives.  The stabilizers may be incorporated in the material before or after polymerization or used as a filter layer. Examples describe the preparation of foils of polyvinyl chloride plasticized with dioctyl phthalate, polyethylene, and polypropylene; polyester sheets prepared from phthalic acid-maleic acid-ethylene glycol in monostyrene; filaments prepared from polyamide chips pigmented with titanium dioxide; all stabilized by the addition of hydroxyphenyl-1,3,5-triazines of above formula.ALSO:Stabilisers against heat, air, and especially ultraviolet light for textiles which may be of animal or vegetable origin and which may be in any form, e.g. fibres, filaments, yarns, woven or knitted fabrics or felt, or paper cardboard or paper pulp, comprise hydroxy phenol-1, 3, 5-triazines of formula:-  <FORM:1065425/D1-D2/1> where R represents a hydroxybenzene residue with a hydroxy group in the ortho position to the triazine, and the the para position a residue. <FORM:1065425/D1-D2/2> where D represents or organic residue and n= 1 or 2, A represents a benzene residue and X a halogen atom or a benzene residue (see Division C2).  The compounds may also be included in coating or dressing agents for the above based on the starch, casein, or synthetic resins.ALSO:Hydroxyphenyl-1,3,5-triazines of formula <FORM:1065425/A5-A6/1> where R represents a hydroxybenzene residue which contains in the ortho-position to the bond to the triazine ring a hydroxyl group and in the para-position to that bond a residue of the formula <FORM:1065425/A5-A6/2> where D represents an organic residue and n = 1 or 2, A represents a benzene residue and X a halogen atom or a benzene residue (see Division C2) are used as stabilisers against heat, air and ultra-violet rays in perfumes, dyed or undyed soaps and bath salts, skin and face creams, powders repellants and sunburn oil and creams.