What should I do if the silicone I bought has a strange smell? Is it harmful to the human body?

Silicone has excellent temperature resistance, can hold high and low temperatures, and is not easy to age. There are many types of silicone, suitable for different places.

Silicone is not only used in silicone pacifiers, but also in silicone molds, adult products, and medical prostheses.

But many people think that used silicone utensils can smell bad.

What exactly is this odor? Is it really harmful to the human body? Is silicone really safe?

We purchased several popular silicone products online to try to find the source of the odor and see if there is any solution.

1. Volatile substance detection First, we try to test the volatile substances of silica gel.

After testing with headspace-gas chromatography-mass spectrometry (HS-GC/MS), we found that all silica gel samples volatilized a substance

——Octamethylcyclotetrasiloxane, referred to as D4. (The picture below is an example of one of the products)

We did a quantitative analysis and found that the total D4 content of one of the products was 309 mg/kg.

D4 is the most basic organic silicon raw material and can be used to synthesize silicone rubber, silicone oil, etc. We infer that the D4 detected this time may be the monomer residue of the synthesized silicone rubber at that time.

D4 is considered a substance of very high concern in the EU, mainly because it may be harmful to the reproductive system and has persistent bioaccumulation.

At the same time, the European Union has also set limits on such substances, but they are mainly aimed at limiting the amount of toiletries.

Judging from the results, there is not much D4 residue left, about 0.03% in terms of proportion. This value is relatively safe, so there is no need to worry too much.

D4 does not have a strong odor, so it can be judged that it is not a possible source of the silicone odor. The headspace method itself has limitations. It cannot determine the type of substance that evaporates after a certain temperature, and its accuracy is slightly insufficient. Our attempt to find the source of the odor encountered a bottleneck.

We will not stop exploring odor and will seek better detection equipment and methods.

2. Although we cannot find the possible source of the odor through the experiment of promoting the volatilization of volatile substances, we can try to find a way to remove the odor. There are always more solutions than problems. Just like the non-stick pan, we changed our thinking.

Referring to the actual situation in everyone's home, we tried several experiments to promote the volatilization of volatile substances.

(Note: The pre-treatment method refers to the national standard method for pacifiers. The weighing stage is carried out after the sample weight is stable in the constant temperature and humidity room of the laboratory.)

Method 1: After boiling in high temperature water for 10 minutes, test the remaining mass

Method 2: After baking in a 200℃ oven for 30 minutes, test the remaining mass

After treatment, the total mass of basically all silicone products decreased by 0.5~1.5%, which means that after treatment, some substances evaporated.

There is no requirement for volatile matter content in most silicone products, but there is a limit in the national standard for pacifiers, which needs to be less than 0.5%.

We conducted volatile matter tests on these treated silicone products again and found that no D4 was detected and the odor was greatly reduced.

From this we can see that odor can be reduced in effective ways, and these methods are also effective in removing D4.

In addition, it can be found in the table that the popsicle mold melted after being baked in the oven at 200℃ for 30 minutes.

It stands to reason that silicone can withstand this temperature. But when we take a closer look, we find that this mold is actually TPE covered with silicone!

The temperature that TPE can accept is below 120℃, no wonder it melted, what a bummer!

Therefore, everyone must pay attention when purchasing whether the so-called "silicone" is real silicone or a wolf in sheep's clothing.

3. Is silicone safe? Silicone itself is a relatively safe material. The highest temperature it can withstand can reach 200~300℃, and it can withstand the lowest temperature that people may encounter in daily life.

Although we were unable to determine the source of the silicone odor through testing, we can make some guesses based on analysis and research of the material.

Various additives are used in the production process of silicone products. This odor is generally produced by the reaction of accelerators and vulcanizers. Some manufacturers will choose relatively suitable additives for this, or add suitable chemical additives to react it.

However, most manufacturers will use flavors or odor masking agents, deodorants, etc. to cover up the smell, which may cause odor rebound. As time goes by, the flavor gradually evaporates, and the odor produced by the additives cannot be covered up and will still come out.

Based on the odor, you can remove the odor according to our two methods (boiling and baking).

Finally, let me give you a summary:

Many times, people always think that evaluation is just about getting a result, but we have been working hard to show the process as much as possible. Although the article is long and contains a lot of data, it may seem a bit tiring, but the process of solving a problem is often more valuable than a result.

In fact, we cannot give a clear result and answer to the silicone test this time and the non-stick pan test last time. But these fruitless tests are not meaningless, they lead us to find more possibilities.

There is no single choice in this world. As long as we are determined to resist harm, every choice will be appropriate and correct.