Among the most requested (over 500 clicks) in the survey on the topics that you would like to deepen are the “cosmetic treatments for nails” that we can call “onychocosmetics” (from the Greek ónychos).
The nail
Onychocosmetics
Alarms: real risks and paranoia
Conclusion
Nail products are mostly part of decorative cosmetics, such as make-up, even if somewhere there is talk of “healthy” nails or products to “strengthen them”.
Particular interest is then focused on the health risks deriving from cosmetic nail treatments. It is talked about both in the professional sphere and for the home use of some cosmetics and on the net there are alarms about the presence of some ingredients defined as “toxic”.
The nail
The human nail is a skin attachment recognizable by a multilayer, semi-transparent sheet composed mainly of keratin at the end of the fingers. The nail plate, that is the outermost section of the nail, is composed of “dead” tissues, such as hair or hair, which cannot be “sick” or “cured”, but can manifest dozens of pathologies with physical signs and dystrophies systemic or cutaneous.
Like all “dead” tissues, nails do not “breathe”, at most they are permeable to fluids or gases.
Nail growth
Like hair, the nail grows, typically in adult individuals 1.5 to 2 mm / month in the feet, twice as much in the hands. Growth rate can also be affected by underlying disorders and diseases.
Permeability of the nails
Like hair, it is relatively permeable to water and other substances. In tests with diffusion cells, a flow ranging from 7 to 17 mg / cm² / h was measured. In the past, less permeability was found.
Considering the thickness of the lamina, the possibility of having some substance penetrate so that it reaches the nail bed are however few. Many studies conducted to evaluate antifungal therapies have shown that the permeability of the nails, like that of the skin, depends on the molecular weight and on any permeabilizing systems. The normal lipid vehicles and some solvents (eg dimethyl sulfoxide), which work on the skin, are not as effective in the nails.
These data lead to the conclusion that the protective barrier of the nail plate, even if less water-repellent than the stratum corneum, is also highly effective against any toxic agents and that the main risks are due to inhalation and contact, more or less accidental, with the skin.
Onychocosmetics
The paraphernalia of those who practice nail cosmetics is vast:
scissors, nippers, files, cutters, brushes, UV or LED ovens to apply nail polishes, semi-permanent enamels, gels or acrylics for nail reconstruction, fabrics (wraps), artificial nails ( tips) which can also be sculpted.
In some cases the classification and legal definition can be ambiguous.
A nail polish is arbitrarily defined as semi-permanent when it adopts a specific formulation solution that increases its thickness and duration once applied. No standard defines how long it should last compared to a normal enamel or which formulation technique should be used to obtain these performances.
Wrap and tips then are not in legal terms of cosmetics and various interpretations are possible for how the glues with which they are applied should be considered.
The fashion / market of nail art, reconstruction and artificial nails is relatively young, it has created new professional figures and commercial activities dedicated exclusively to onychocosmetics.
Unfortunately there is a lot of improvisation and spontaneity around and despite the proliferation of training courses, the professionalism and competence of many operators, but also of some suppliers of cosmetics and accessories, is questionable.
The procedures to guarantee the safety and quality of various onychocosmetic applications are not trivial, precise protocols must be followed.
It is definitely disconcerting to see nail technicians convinced that to make resins or adhesives adhere better, it is necessary to file until the surface of the nail plate is satin (not smooth and shiny). It’s not just nonsense as adhesives work best on smooth surfaces, it’s a rationale-less procedure that introduces unwarranted risks.
Equally disconcerting to see how many nail products are reported by Rapex (the European rapid alert system) and that a survey published by l’Altroconsumo revealed how various semi-permanent nail polishes on the Italian market were not up to standard.
Alarms: real risks and paranoia
The buzz on the internet and other media reads more or less:
Gel manicure could be carcinogenic
Glamorous nails: beware of the risks
Is your nail polish toxic?
It is rarely pointed out that the well-documented risks of beauticians, nail technicians and nail cosmetics professionals are substantially different from the risks of those who apply or have nail polish applied.
Chemical risk
The chemical risk depends on the contact route, i.e. on whether the dangerous substance is inhaled, touched or ingested, and on the exposure, i.e. on the amount and duration of contact.
Do not be surprised if the beautician who applies a semi-permanent polish or makes a nail reconstruction wears gloves, mask and protective glasses, can be exposed 8 or 10 hours a day to these substances.
For end users, the risk is much lower unless they have the insane passion of “snorting” cosmetic bottles for a long time, with enamels, solvents or glues, or who do not apply products formulated for nails to large surfaces of the skin or who, worse still, they don’t drink them.
In the professional field, the risk of inhaling fine powders is significant, even the filing of the nail is not exactly harmless, or volatile or gaseous substances.
More significant, even for the end user, is the risk of allergic dermatitis given that some of the substances under investigation have a significant allergenic potential and that those who are severely allergic can react by exposing themselves to even minimal amounts of the allergen or hapten.
In the professional field, the substances for which potential risks due to excessive exposure must be considered are:
◾Volatile solvents: in particular the most used: toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, ethyl acetate, isopropyl acetate, acetone, alcohol. None of these substances are really good if inhaled in large quantities or if you bathe in them but Toluene (max. Concentration allowed in the EU: 25%), Xylene and Methyl ethyl ketone, raise various additional concerns and the industry is trying to replace them and the professionals to avoid them.
◾ Acrylic acid monomers: ethyl methacrylate, methacrylic acid, methyl methacrylate.Not to be confused with polymers which, in addition to not being volatile, have a much less problematic toxicological profile. Unfortunately, by launching alarms for all cosmetics where the term acrylates appears among the ingredients , it also applies to the term formhaldeide, the consumer may think that many polymers are potentially toxic that are not actually toxic. It should be noted that monomers, in particular Methyl methacrylate, are considered substances with a high allergenic / sensitizing potential and, even if they are not specifically banned or limited by the regulation, in some countries (Germany Sweden etc.) cosmetics composed of 80% or more of these substances, generally base liquids for nail reconstruction, can be withdrawn from the market or their import can be blocked. I am not aware that the Italian health authorities adopt the same criterion.
Even in the USA the FDA, in the 1970s, acted, with legal actions and withdrawals from the market against those who sold cosmetics with a high concentration (up to 100%) of methacrylate monomers, but these substances were not legally prohibited and are still today. widely used in nail reconstruction and in the application of artificial nails.
◾Formaldehyde: there is still the mistake of considering formaldehyde a cosmetic ingredient. Formaldehyde being a gas does not enter at all as an ingredient in cosmetics, at most methylene glycol and paraformaldehyde enter it , the main constituents of formalin, which can release formaldehyde under particular conditions. EU regulations limit their use only to hardening products with maximum concentrations of free Formaldehyde equal to 5%. The SCCS in its opinion considers a concentration of free Formaldehyde equal to 2.2% to be safe in nail cosmetics provided that the environment is ventilated. Formaldehyde is ubiquitous, we probably inhale more from being near a lit fireplace or in a room with 3 or 4 lit incensors but in a work environment where substances that can release it are used, it is certainly better to have good ventilation.
◾ Hydroquinone and hydroquinone methylether: they can be found as “stabilizers” as they slow down the polymerization of methylacrilate, the EU admits a maximum concentration of 0.02% after mixing.
Due to the copy-paste from various American sites, the alarm is then often
raised for ◾Dibutyl phthalate, Diethylhexyl phthalate, Benzyl butyl phthalate: plasticizers that make resins and polymers flexible and less subject to microcracks and shrinkage.
◾Acetonitrile: Often used in products to remove artificial nails.
These are all ingredients today absolutely prohibited by European standards and therefore should not enter into any concentration in any cosmetic sold here.
So if you find cosmetics that declare their presence in the ingredients list, report them. They must be withdrawn from the market and whoever puts them on the market without respecting the rules is punishable.
Some of the substances discussed or considered dangerous are potential endocrine disruptors.
Other ingredients used to make nail resins plastic and flexible such as triphenyl phosphate or camphor (INCI: camphor ) are also accused of being potential endocrine disruptors. The potential adverse activity of these substances is the subject of study and controversy. In nail products, the question arises as to how many endocrine disruptors can be released through the nail plate by a polymer or a solid resin.
In addition to the ingredients declared on the label, in pigmented nail products, one must consider the risk that some toxic metals are present, in particular Antimony, its oxides have been used for a long time as a pigment (Kohl) and as glitter, in addition to Lead and Chromium.
Infectious risk
While the chemical risk is relevant above all for professionals, the risk of infections is greater for those who undergo or have treatment done.
The tools with which to cut, shape, file the nails must be sterilized as they easily injure the skin and can transmit infections, especially if used on several people. But the predominant infectious risk since the fashion of semi-permanent enamels, reconstruction and artificial nails exploded is due to fungal infections that can develop in particular conditions, delamination, micro-cracks due to shrinkage, etc., typical of applications not performed. correctly or with unsuitable products.
Onychomycosis
Up to 20 years ago onychomycosis was known by 1 in 20,000 people (estimate by nose) and even dermatologists had considerable difficulty in recognizing it without microbiological analysis. Today, thanks also to dozens of TV commercials, people talk about it in bars and lounges with the same ease with which they talk about football. It is a fungal, yeast or mold infection that penetrates the nail plate. Many studies on the permeability of the nail plate have been conducted to verify the possibility of getting an antibiotic / antifungal into the nail.
The spread and proliferation of the fungus or yeasts depends on humidity and incorrect applications and formulations of semi-permanent enamels, artificial nails or acrylics can favor their accumulation.
UV risk
In literature, some time ago, there have been reported cases of serious adverse reactions attributed to exposure of the hands to the UV rays necessary to accelerate the polymerization of the resins. The matter is also the subject of controversy because the dose of UV administered is at least on paper relatively low and if the risk were real, all artificial tanning systems would have to be banned from the market. Some research has established that if the risk is there, it is still very low. There are no data on the possible biological interaction between UV and substances used in onychocosmetics. Regardless of the probably irrelevant relationship between cancer and UV nail lamps, the fact remains that UV accelerates skin aging as well as the polymerization of resins.
Since curing is also accelerated with heat and blue light, UV-free “ovens” are now available which I would prefer a priori.
Conclusion
The concerns, decidedly founded, for the safety and health of nail care professionals are not transferable tout court on final consumers. A certain chemophobic alarmism warns final consumers of toxic ingredients that are not toxic and that bound in a resin applied to the nail cannot have any systemic effect on health. Any risks can be extremely reduced by following correct application procedures and carefully avoiding the use of substances to which you may be sensitized. Reading and understanding the ingredients list and the warnings and instructions for use is essential for professionals and non-professionals alike.
Unfortunately, the safety and quality of a cosmetic treatment depends more and more on the honesty and competence of those who perform or produce it than on the ingredients list. Imported nail products that are not up to standards and poorly executed treatments are not uncommon.
Rodolfo Baraldini