Especially during the "return of the south wind", this small package is too dangerous! Many people have it at home...

In daily life

Some foods come with a small packet of desiccant.

Everyone knows that it is not edible.

But do you know?

It’s actually a dangerous item.

Recently, the return of the south wind "visited" Quanzhou, and it was wet both outside and inside the house. Ms. Hu, who lives in the city, was also troubled by this. She threw the desiccant that came with her granddaughter's snacks into the bathroom and kitchen to dehumidify, but the desiccant became hot after a while . Ms. Hu was worried that it would explode, so she threw it away immediately.

So

What are the ingredients of desiccant?

Why does it become hot when it comes into contact with water?

Will it explode?

Are there any other dangers?

▲Firefighters holding desiccant

With questions from citizens

Firefighters conduct experiments on site

Let's answer your questions together

In the early stage, we randomly bought some children's foods with desiccants such as seaweed flakes in the supermarket and observed that these foods were outsourced, and many foods stated that the main ingredient of the desiccant was quicklime.

▲The outer packaging indicates that "the main ingredient of the desiccant is quicklime. It is not edible, cannot be opened, and cannot be immersed in water to avoid burns to the skin or eyes."

Among them, the back of a certain brand of seaweed packaging has the following reminders: "Do not eat, do not open, do not soak in water to avoid burns to the skin or eyes"

▲Firefighters add granular desiccant into mineral water bottles

▲Firefighters add lime-like desiccant to mineral water bottles

In the experiment, firefighters selected a granular and a lime-like desiccant from two different brands of seaweed, put them into two mineral water bottles, poured about half a bottle of water into them, and then shook them. The experiment found that the lime-like desiccant quickly became hot after adding a small amount of water, but when more water was added, the temperature rose less.

▲Granular desiccant (left) and lime-like desiccant (middle and right)

When the amount of water increases, the lime-like desiccant quickly dissolves into the water, the water turns milky white, and bubbles emerge in the water, while the granular desiccant has almost no reaction when it comes into contact with water.

▲Water was poured into the desiccant for a long time, and no explosion occurred.

The entire experiment lasted nearly half an hour and no explosion occurred.

So

Desiccant in food

Is it dangerous?

The danger is still not to be underestimated

According to Liu Jinzhen, a chemistry teaching and research member of Hui'an County Teachers' Training School, there are many types of desiccants. For example, the desiccant in mooncakes is iron powder, whose main function is to absorb water and oxygen, and it is relatively safe.

"Lime is dangerous." Teacher Liu said that there are two main dangers of lime: First, after it reacts with water, it will produce calcium hydroxide, which is corrosive. Second, lime will release heat when it comes into contact with water, which will cause burns. According to Teacher Liu, in the heat release experiment of quicklime he has done, the temperature reached 110 degrees. Teacher Liu said that the instant meals on the market are heated with quicklime.

Teacher Liu reminded that if there are infants and young children at home, the desiccant should be disposed of promptly and properly after the food bag is opened to prevent children from accidentally ingesting it or getting burned due to playing.