The expiration date of table salt is three years.

The shelf life of salt is usually three years. According to our regulations, the shelf life of table salt is three years. If it is unopened salt put three years is not recommended to eat, but if it is opened salt, put 2 to 3 months is also best not to eat, because now the salt will add some other trace elements, will affect the shelf life of salt.

The types of salt are sea salt, well salt, mineral salt, lake salt, earth salt and so on. The main component of salt is sodium chloride, and the state regulations stipulate that the sodium chloride content of well salt and mine salt shall not be less than 95%. Table salt contains barium salt, chloride, magnesium, lead, arsenic, zinc, sulfate and other impurities. Table salt is iodized salt made by adding a certain amount of iodine agent to refined salt, crushed and washed salt, and sun-dried salt.

Classification of salt

1, lake salt: lake salt refers to salt extracted from salt lakes. China's salt lakes are widely distributed, and the areas that are rich in lake salt are Qinghai, Sichuan, Gansu and so on. Lake salt is characterized by rich minerals, soft taste. The Haixi Salt Lake in Qinghai and the Guanting Salt Lake in Sichuan are important producing areas of lake salt in China. The high-quality lake salt used in many high-grade foods and seasonings comes from China's salt lakes.

2. Well-mined salt: Well-mined salt refers to salt mined from underground salt mines. China's underground salt mines are rich in reserves and widely distributed. The salt in the salt mines around the world is evaporated from the ancient seawater left over millions of years ago. Well-mined salt is popular among consumers for its high purity and fine texture. For example, Yancheng Yanchi is one of the famous well mine salt producing areas in China.

3, sea salt: China's largest production of sea salt salt farms, mainly located in Tianjin City and Hebei Province along the Bohai Sea, of which Tanggu Salt Farm is the largest, with an annual output of 1.19 million tons of salt. Changlu salt field south from Huanghua, north to the south of Shanhaiguan, including Tanggu, Hangu, Dagu, Nambourg, Daqinghe and other salt fields, including a total length of 370 kilometers, *** there are more than 2.3 million acres of salt fields, with an annual output of more than 3 million tons of sea salt.