What is Laureth-7, an ingredient in cosmetics?

Is Laureth-7 Natural?

Laureth-7 is a cosmetic ingredient made from lauryl alcohol. It is often used in cosmetics as well as laundry detergents.

Lauryl alcohol can be derived from coconut and palm oils, so laureth-7 may also be found in natural cosmetics .

However, there is also lauryl alcohol derived from petroleum. The reality is that it is difficult to tell from the ingredient name alone whether Laureth-7 is natural or not.

The role of laureth-7

Laureth-7 is used in cosmetics as an emulsifier and surfactant, mixing water and oil, which do not normally mix, and keeping them together.
Cosmetics are made from water and oil, so these ingredients are necessary.

There are many other types of Laureth with different numbers, such as "Laureth-2" and "Laureth-23."

The larger the number at the end, the better the compatibility with water. Different functionalities are available so that they can be used according to the other ingredients and properties used in cosmetics.

Laureth is a member of the PEG family

PEG is an ingredient used in many cosmetics. Although the names are different, laureth is actually a member of the PEG family. In general, both are considered to be gentle on the skin and highly safe.

However, there is one thing that concerns me about the manufacturing process: both laureth and PEG go through a process called ethoxylation.

Ethoxylation with ethylene oxide

Both laureth and PEG are manufactured using the chemical ethylene oxide, which is produced through a process called ethoxylation, which involves a chemical reaction between ethylene oxide and other substances.

This ethoxylation reduces the irritation of the substance, making it possible to create cosmetic ingredients that are less irritating to the skin.

However, there are some scary aspects to this ethoxylation.

This is because a substance called 1,4-dioxane is produced, and trace amounts of 1,4-dioxane and ethylene oxide may remain in the finished cosmetic product.

Why are they so scary? Let's take a closer look at these two substances.

What is 1,4-Dioxane?

1,4-Dioxane is a clear liquid that is easily soluble in water.
Studies have shown that it is easily absorbed through the skin, it is listed as a possible human carcinogen by the International Agency for Research on Cancer (IARC), and is listed as a suspected carcinogen under California's Proposition 65 .

A report from the U.S. Agency for Toxic Substances and Disease Registry lists the effects of different levels of exposure to 1,4-dioxane.

In case of short-term contact

• nausea
• Drowsiness
• headache
• Eye, nose, and throat irritation

In case of prolonged contact

• Dermatitis, eczema, dry or cracked skin
• Liver and kidney damage

What is Ethylene Oxide?

Ethylene oxide is a colorless gas.
It is classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen , and is listed under California's Proposition 65 as a risk factor for carcinogenesis, reproductive toxicity, and developmental toxicity.

Both 1,4-dioxane and ethylene oxide are highly toxic substances that are subject to various regulations in each country.

Is Laureth-7 Safe?

Such Laureth-7 is made through ethoxylation. Is it safe to put on the skin?

Generally, laureth-7 is considered a safe ingredient that is gentle on the skin.

Regarding the contamination of food with 1,4-dioxane mentioned above, recent studies in the United States have reported that residual concentrations have been significantly reduced.

Incidentally, until about 10 years ago, the actual residual concentrations of 1,4-dioxane in cosmetics in Japan were unknown.

In 2013, the health risks posed by residual 1,4-dioxane began to attract attention around the world, and consideration of regulation began.
A method for measuring residual concentrations of 1,4-dioxane in cosmetics was finally established in Japan. Measurements using this method showed that 1,4-dioxane was detected at concentrations of 2.78μ/g in shampoos and 3.31μ/g in hand soaps sold at the time.

Although it was detected, it was only in very small amounts.
There may be even less of them now, but we don't know if they have been completely removed.

Other Ethoxylated Ingredients

Laureth-7 isn't the only ingredient manufactured with ethylene oxide that can leave 1,4-dioxane residues, so if you want to avoid it, here are some other ingredients to look out for:

• PEG
• PPG
• Polysorbate
• Laureth (other than 7)
• Steares (numbers at the end)
• Ceteareth (number after)

Even if only minute traces of makeup remain, it is something that you put on your skin every day, and if you include body and hair care products, it comes into contact with your entire body.

There may not be any need to worry too much, but it's best to choose something that you and your loved ones can use with peace of mind.