A study found that the nitrite content of fresh vegetables will increase at room temperature and refrigerated for two days, and will be higher than the national standard limit to varying degrees, causing mild to severe poisoning to human body. In this regard, a study found that the nitrite content of fresh vegetables will increase at room temperature and refrigerated for two days, and will be higher than the national standard b value to varying degrees, The results showed that the content of nitrite in vegetables decreased significantly and soon decreased to a safe value. 
the researchers believe that long-term vegetables can be used safely after being washed with fruit and vegetable detergent.
Soaking in clean water for more than 20 minutes can also achieve the same effect in the experiment