With a residual monomer, according to the manufacturer to provide data, China's production of PS is the strict implementation of national styrene monomer content shall not be more than 1000ppm standard, the acceptance criteria for the U. S. Food and Drug Administration (FDA) to 5000ppm, Japan's Food Sanitation Law for food packaging plastic products and containers of PS, the volatile substances (styrene, toluene, ethylbenzene, cumene, is total concentration of butadiene styrene) must below 5000ppm, but as for soup foam containers and its total concentration must be below 2000ppm. Among them, styrene, isoprene dimerization and ethylbenzene concentration should not exceed 1000ppm. Other food containers with PS, the total concentration must be below 10000 PPM.
　　On PS foam plastic tableware heated above 65 DEG C using the release of monomers, this is no scientific basis of, because polystyrene molecular structure is relatively stable and depolymerized to monomer, the temperature must be above 250 DEG C. Even if the raw materials in molecular structure containing standards allow the amounts of monomer, but in actual use has fully proved that the single experience immediately vaporized into the air, residue in food or utensils have only a slim chance of, even if the residue, due to the little volume, normal liver to metabolism through out, not on the human body harm. According to the British "reinforced plastics" in 1992 second report, the United States Environmental Protection Agency (EPA) has been considered to be carcinogens of styrene, from the "carcinogenic" list in the ditch. In the same article also reported a report in the Journal of Materials Engineering "magazine pointed out: the decision is based on the expansion of a scientific data, and the EPA drinking our recognition of (odw) was published. In the United States federal (material) registration, styrene was ultimately ruled as a compound that is not considered as a compound with sufficient carcinogenic potential. Drinking water division pointed out that in the full study of drinking water, did not find a carcinogenic reaction of styrene. This decision has been incorporated in the EPA formulation of the final rule of drinking water impurities in the maximum content of 38 kinds of chemical substances, in which styrene content of 0.1MG/1 drinking water, no significant harm to human health. Another National Cancer Research Institute (LARC) has said: there is not enough evidence to prove that styrene monomer to humans or experimental animals are carcinogenic, the conclusion.