Finding and finding a good glue can be very difficult and confusing at times. Especially if your client or you have allergic reactions or sensitive eyes. We will try to explain what to pay attention to and make the choice a little easier without going too deep into chemistry.
Main components of glue
The first thing to start with is to understand what the glue contains:
Cyanoacrylate
The main culprit behind allergic reactions to eyelash glue is a chemical called “cyanoacrylate” which is the main ingredient in all eyelash extension glues. At the same time, this is the component that will determine the properties of your glue. ALL eyelash extension glues contain cyanoacrylate and there is currently no real alternative.
It has been proven that 3-5% of people developed an allergy to cyanoacrylate or one of the acrylates during their lifetime. An allergy to eyelash extension glue can develop after a long time, even years. This is why we recommend a patch test before applying eyelash extensions for the first time. If you or your client is allergic to any of the acrylates or the entire group of acrylates, then 99% of you will also have a reaction to the eyelash extension glue.
If many still know about this main component of glue, few know that there are different types of cyanoacrylate. There are types that are very bad and very quickly cause allergies.
Types of cyanoacrylate and their properties.
| Methyl | Ethyl | Butyl | Alkoxy | Methoxy | Octyl | |
| Fumes | Very strong | Average | Low | Very low | The lowest | Very low |
| Persistence | Very strong | Strong | Low | Low | The lowest | Low |
| Notes | Industrial class. No valid eyelashes for augmentation. |
Most used in eyelash extensions | Medical. Good for sensitive people |
Great for sensitive people. Very expensive and therefore rare. | Medical. Difficult to use in eyelash extensions |
Medical. Used in medicine instead of sutures. |
- Methyl cyanoacrylate: This is a toxic substance. This type of cyanoacrylate is strictly classified and used for industrial purposes. In the very beginnings of eyelash extensions, this was the most popular type. If you come across this nowadays, run away from such glue! This type is very strong and can dissolve proteins, if used for eyelash extensions it can lead to permanent vision loss. Under no circumstances should this type be used in eyelash extension glues. Allergy guaranteed!
- Ethyl cyanoacrylate: The most commonly used type of cyanoacrylate for eyelash extension adhesives. Its drying time is fast and the staying power is strong. For unpurified or low-level cyanoacrylate, the fumes and irritation will be quite strong, leading to allergies in the long run. In recent years it has been achieved that Ethyl cyanoacrylate can and is purified to a medical level, making this popular form much safer.
- Alkoxy Cyanoacrylate : Formulated to have extremely low odor and fumes. This type of cyanoacrylate is eight to nine times more expensive than Ethyl cyanoacrylate and is rarely used in eyelash extension adhesives due to its high price. There are cases when this is used in a mixture with other types.
- Butyl cyanoacrylate: considered and formulated to be hypoallergenic. It was originally developed for use in medical procedures (an alternative to sutures, etc.). Compared to Ethyl, drying speed is slower and durability is weaker.
- Methoxy cyanoacrylate: The least irritating type of cyanoacrylate and is almost odorless. It is formulated to improve the irritation and odor problems caused by Ethyl and Butyl cyanoacrylate. However, its drying time is very slow and the durability is much weaker compared to other types of cyanoacrylate (only up to 10 days).
- Octyl cyanoacrylate: Low irritant and almost odorless. Difficult to obtain and expensive, so it is practically not found in eyelash glues. It costs 50€ per ml. Less persistent than Ethyl, but more persistent than Methoxy. Officially approved suture substitute in surgery.
- Polyacrylate – a novelty that has appeared in recent years as a substitute for cyanoacrylate adhesives. Unfortunately, it is basically the same group of acrylates and even more harmful than cyanoacrylate. From these one piece at a time, if you don’t want severe consequences.
Developing the right formula for low fumes, fast drying and long lasting is the most challenging goal for any adhesive manufacturer. The more the hold is extended and the drying speed reduced, the more irritating the adhesive remains.
Latex
Latex (natural rubber) is known to cause allergic reactions in quite a few people, so it is not recommended to use glue that contains latex. Instead, choose an adhesive that contains an elastomer (synthetic rubber), which is a lab-made rubber that does not cause latex allergies, but gives the adhesive superior viscosity, flexibility, and durability.
Formaldehyde
There is no such thing as a completely formaldehyde-free glue, because when the glue breaks down over time, a very small amount of formaldehyde is naturally produced. The main difference is that there are companies that add additional formaldehyde because it is a very cheap raw material. The main harm of formaldehyde is that it is a toxic carcinogen that quickly leads to severe allergies and in the long term to cancer. Formaldehyde should not be feared because it has been proven that we humans naturally create and release small amounts of formaldehyde (in our breath). The main thing is to check whether formaldehyde has been added.
PMMA – polymethyl methacrylate.
A liquid plastic that makes cyanoacrylate stronger, similar to iron rebar inside concrete. Without PMMA, cyanoacrylate is strong but crumbling, just like concrete without rebar reinforcement. It’s like a glue skeleton.
Carbon black
Carbon black is included in 99% of adhesives. For some people, it is this ingredient that causes allergies, not the acrylates.
Expiration date
Did you know that glues created for especially sensitive people have a shorter shelf life? Regular adhesives have a shelf life of 6 – 7 months, whereas adhesives intended for particularly sensitive people will only last up to 3 months.
Persistence
Adhesives made for sensitive people have a very short shelf life. Persistence can be from 5 days to 3 weeks maximum. As with drying speed, as the glue becomes more persistent, it also becomes more irritating.
Common glues have a durability of 4-8 weeks, there are also rare exceptions with longer durability, but they are also mostly very harmful and we recommend avoiding them. In principle, it should be taken into account that the longer the glue lasts, the more irritating and allergy-causing it will be.
Drying speed
You may have already noticed that for glue sensitive people, the drying speed is significantly slower than that of regular eyelash glue. For people sensitive to glue, the drying range will be between 4 seconds and 8 seconds, and for regular glue 0.3 – 3 seconds. The faster the glue, the more irritating it will be.
How is the drying time calculated?
The drying time (indicated on the package) is calculated from the moment when the glue comes into contact with the natural eyelash, not from the moment when the eyelash is dipped into the glue. This means that the 1 second quick glue gives you 1 second of time to adjust the lash when it is in contact with the natural. Moving the lash afterwards will mean less hold. This drying time is valid if you work in suitable conditions and space. As soon as you have increased humidity in the room or chemicals in the air that activate polymerization, this time delay will start from the moment when the glue comes into contact with this reagent.
Cyanoacrylate distillation (purity) classes
We have created a picture for better visibility and understanding. Shown is the total mass with 100kg of cyanoacrylate.
Cyanoacrylate is purified during the distillation process. The higher the class, the cleaner and less irritating as well as the more expensive it remains. This does not mean that there will be no allergic reaction or irritation to medical grade cyanocarylate. The higher the class, the less fumes and smell, but the bad properties of cyanoacrylate, less affecting, but still remained. Take into account and do not fall for marketing tricks such as “Hypoallergenic”, “No irritation”, “Does not affect health” and the like, because there are usually not such with cyanoacrylate in the composition! We will write more about allergies in another post.
Oil proof or oil resistance: this often causes confusion and some do not know what it means. Any cyanocarylate, unless specially adapted, degrades rapidly on contact with oil. Therefore, it can be observed that clients with more oily skin have less eyelashes. There are adhesives that have an improved composition and are oil resistant. Oil-resistant does not mean that oil and fat will not affect it at all, they will, but less and the eyelashes will last longer. On the other hand, oil-resistant is specially designed so that oils do not affect the adhesive and do not degrade it, so it is very suitable for customers with oily skin. This does not mean that oil-resistant will not be suitable for people with dry or combination skin. Customers who sweat more, have oily skin, apply creams and cosmetics in the eye area will feel this property of the glue very positively.
