Why are my hands still oily when I eat crayfish even though I'm wearing gloves? I finally figured out what's going on

Expert of this article: Chu Yuhao, PhD of Beijing University of Chemical Technology, engineer of Sinopec Beijing Research Institute of Chemical Industry

How delicious is crayfish?

Break it with your hands

Separate the shrimp head from the body

A bite of shrimp

A bite of shrimp roe

That taste is really...

Are you all hungry after watching this?

etc.

I have a question, I don't know if you have noticed it.

When eating crayfish

Are they all wearing disposable gloves?

But why do my hands always get greasy after eating?

Are the gloves torn?

I checked and found nothing.

What's going on?

Could it be that the disposable gloves were dissolved?

Is this harmful to our body?

Let’s learn about it together today

What are disposable gloves made of?

At present, there are three main types of disposable gloves on the market: latex gloves, PVC gloves and PE gloves.

Latex gloves are mainly used in the fields of medicine and scientific research. PVC gloves are generally not used in the food field because of their low heat resistance and the addition of plasticizers during the production process.

Therefore, most of the disposable gloves we use in the food industry are polyethylene (PE) gloves.

Why are my hands still oily after putting on gloves?

I believe everyone must have had this problem: when eating crayfish, you are clearly wearing gloves, or even two layers of gloves, so why are your hands still full of oil?

The polyethylene raw materials used in the production of disposable film gloves are mainly low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). LDPE and LLDPE have lower density and contain more branched polymer molecules, resulting in larger molecular gaps between polymer chains.

Moreover, according to the "like dissolves like" principle, when in contact with grease, LDPE and LLDPE may swell to a certain extent, causing the grease molecules to pass through the disposable gloves through gaps that are invisible to our naked eyes.

You may be worried that if the oil penetrates the gloves, does it mean that the polyethylene has been dissolved by the oil?

PE products produced in accordance with qualified regulations are inherently resistant to acid, alkali and oil. Therefore, short-term contact with grease at non-high temperatures will basically not cause the PE material to dissolve.

Why do we still wear disposable gloves if they will get oily?

Since wearing disposable gloves still cannot prevent the penetration of oil molecules, why do we still wear them?

In fact, the biggest purpose of wearing disposable gloves when handling food is not to prevent grease, but to block bacteria.

In daily life, our fingers are inevitably contaminated with some bacteria, and disposable gloves made of PE material themselves have the effect of preventing bacteria from passing through. Wearing it when eating crayfish can effectively prevent the bacteria on the hands from entering the human body, thereby achieving the purpose of healthy eating.

It is worth noting that when using disposable gloves, try to buy those produced by regular manufacturers. Inferior disposable gloves may be made of recyclable waste, which further reduces the performance and barrier properties of the gloves. There is also a risk of harmful substances dissolving in the oil and entering the human body.

In short, the current disposable gloves for food still find it difficult to solve the problem of grease penetration. In daily life, we need to face the problem, use them reasonably, and try to choose qualified and compliant products.

What other similar situations occur in life?

So, in addition to disposable gloves being penetrated by high-fat foods such as crayfish and roast duck, what other polymer materials will we encounter being contaminated by oil in our daily lives?

The surface of clothing is more easily stained by oil

Compared with the smooth surface of tiles, the rough surface of clothing is more easily stained by oil and is difficult to wipe off. Because the polymer material that constitutes the surface of clothing has larger intermolecular gaps, oil molecules can more easily penetrate into the interior of the polymer material through the gaps, making cleaning more difficult.

Collars and pillows turn yellow over time

When we are active and sleeping, our bodies will secrete a certain amount of oil. Small molecules of oil will also penetrate through the gaps in the polymer materials on the surface of collars and pillows, and diffuse into the interior of the material, causing the entire material to turn yellow and become difficult to clean.

The oil collecting plastic shell of the range hood turns yellow over time

If you look closely at the small plastic shell that collects oil on the range hood, you will find that the plastic shell will turn yellow to varying degrees as time goes by.

Plastic is also a polymer material, and there are also certain gaps between polymer chains. As time goes by, oil molecules will gradually penetrate into the interior of the plastic shell through the gaps, causing the entire plastic shell to turn yellow.

Therefore, when using polymer materials that are often in contact with grease, we must clean and replace them frequently.

In summary

Disposable gloves used in the food industry

Polyethylene (PE) gloves

The nature of the raw materials themselves

Larger spaces between polymer chains

According to the principle of "like dissolves like"

Even if you wear disposable gloves

It will also make your hands oily.

The main function of this disposable glove is

Block bacteria

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