Food additives are toxic. It is forbidden for catering service providers to buy and use sodium nitrite as a food additive, because sodium nitrite is highly toxic, and a certain dose will cause death. At the same time, sodium nitrite is also a strong oxidant. If eaten by mistake or used improperly, it will lead to hypoxia in human tissues and even cause acute poisoning. In addition, sodium nitrite will react with protein in meat under acidic conditions to generate carcinogenic nitrosamines, so the use of sodium nitrite will be harmful to human health.