Allergenic ingredients in nail polishes

Nail Polishes: A Review on Composition, Presence of Toxic Components, and Inadequate Labeling

Nail polishes were developed in 1920, and since 1940, it has been known that these cosmetics contain toxic and sensitizing components. Over the years, nail polishes have undergone several changes in their formulation to avoid this problem, but new components have also been considered toxic and allergenic. The growing demand for gel nails has also been highlighted in cases of allergy to (meth)acrylates, and the biggest concern that was previously related to the presence of toluene sulfonamide-formaldehyde resin (TSFR) in traditional nail polish formulations is now also part of (meth)acrylate-based cosmetics. The beautification caused by nail polish is the main factor behind its constant use throughout the world, but studies have demonstrated its use for other purposes, such as treating fungal diseases, sun protection factor in cancer patients, and as a possible ally in forensic area. This review brings the beginning of the discovery of nail polish and its trajectory to the present day, including its effects on health and its inadequate labeling. Therefore, it is extremely important that legislation monitors the composition of nail cosmetics and that new formulations are studied to make them safe for health and the environment.

Adverse Effects of Do-It-Yourself Nail Cosmetics: A Literature Review

Background

As self-applied manicures have gained popularity, it is important for physicians to remain informed about potential associated side effects. Traditional polish remains most popular among nail enthusiasts, but the pursuit of durability and convenience accelerated development of other nail cosmetic products, including gel polish, acrylic nails, and press-on nails. Despite documented adverse effects among beauty professionals and salon customers, individuals practicing at-home nail care routines may face similar, if not more, frequent complications due to misinformation, inadequate training, and social media trends.

Summary

This review provides an overview of adverse effects associated with different at-home nail cosmetics. Allergic contact dermatitis is the most prevalent adverse event, primarily attributed to (meth)acrylates found in nail glue, gel polish, and acrylic nails. Other adverse effects include infections, chemical burns, and complications from ultraviolet nail lamps.

Key Message

The review highlights the importance of transparent product labeling and appropriate warning labels from manufacturers, as well as physician education and awareness for minimizing risks related to at-home nail cosmetic applications.

Nickel, cobalt, and chromium in nail sticker and tip products in Korea

BACKGROUND

Nail stickers and nail tips are increasingly used nail products in Korea, and the rest of the world. However, no studies have examined if these specific consumer products might contain nickel, cobalt, and/or chromium, that is, metals known to provoke contact allergy.

OBJECTIVE

We aimed to assess the release and content of nickel, cobalt, and chromium in nail stickers and tips by performing qualitative and quantitative analyses, respectively, of 50 convenience samples purchased in Korea.

METHODS

Eighty-six qualitative spot tests were performed to determine the release of nickel, cobalt, and chromium on 35 nail stickers and 15 nail tips across five brands. Subsequently, the metal contents were quantified using inductively coupled plasma-optical mass spectrometry (ICP-MS).

RESULTS

According to the spot tests, nickel was released in 7/86 (8.1%) tests before and 10/86 (11.6%) tests after exposure to artificial sweat. Cobalt and chromium (VI) spot test results were negative. However, ICP-MS detected nickel, cobalt, and chromium in 11%, 6.3%, and 16.7% of the samples, respectively. Detection rates were higher in nail tips than in stickers and were most common in rhinestones.

CONCLUSION

Nail stickers and tips may contain nickel, cobalt, and/or chromium.

Contact Dermatitis in Nail Cosmetics

Many ingredients found within nail cosmetic products are capable of sensitizing patients’ immune systems and causing contact dermatitis (CD). These include but are not limited to tosylamide, (meth)acrylates, and formaldehyde. A clear temporal relationship between nail cosmetic procedures and an eczematous outbreak on the hands, face, or other ectopic body regions can be a key indicator of CD secondary to nail cosmetic exposure. Once an inciting allergen is identified through patch testing, elimination and avoidance becomes a mainstay of treatment alongside the use of emollients and topical anti-inflammatory therapies. Patients should be counselled to approach future nail cosmetic products and procedures with caution and careful attention to ingredients, regardless of whether or not it has a “hypoallergenic” label.

Evaluation and detection of early nail damage caused by nail enamel

BACKGROUND

Many nail cosmetics have components that are considered irritants or allergens. Due to the current clinical assessment limitations, it is often too late to identify nail enamel hazards until they cause disease. Thus, it is essential to investigate effective methods of detecting minor changes and early lesions in nails before they worsen.

OBJECTIVES

To provide a reliable method to investigate and evaluate nail enamel hazards on nails earlier using ultrasonic equipment.

METHODS

Eighty-three volunteers with smooth, lustrous nails were enrolled after being clinically examined. The thumbnails and middle nails were evaluated before and after using nail enamel for 2 weeks. Nail health was then assessed using three methods: clinical evaluation, nail surface image analysis, and an ultrasonic device.

RESULTS

Using clinical diagnostic and imaging methods for analyzing the nail surface showed no visible differences before and after using nail enamel for 2 weeks. However, there was a significant difference in the nails' depth and density (p < 0.001). The depth had increased 10% for thumbnails (about 20 μm), and the density had decreased by 3.0%. As for middle nails, the depth had increased by 9.4% (about 19 μm), and the density had decreased by 3.0%.

CONCLUSION

The present study provided evidence that nail enamel can significantly irritate hyperplasia and decrease the density of the nails, but detecting that slow process of pathological changes cannot currently be assessed by conventional clinical evaluation and image analysis. Thus, our study provided a practical novel approach for evaluating these visually imperceptible nail changes.

Allergy to hypoallergenic nail polish: does this exist?

The main allergen responsible for contact dermatitis to nail polish is tosylamide-formaldehyde resin. The so-called hypoallergenic nail polishes are suposedly free of agents that commonly trigger reactions. The commercially available products and their compositions were studied. It was observed that most brands present at least one component capable of triggering the disease; therefore, allergic reaction may occur even when hypoallergenic polishes are used. There should be a proper investigation of the specific allergen through a patch test, because more than one component can cause an allergy, and we need to check the exact composition of each product.

A novel mass spectrometric method for formaldehyde in children's personal-care products and water via derivatization with acetylacetone

RATIONALE

New legislation in the state of Minnesota prohibits the sale of children's personal-care products (PCPs) that contain more than 500 ng/mg formaldehyde. Previous attempts to quantify formaldehyde in PCPs use nonspecific derivatization procedures that employ harsh reagents and/or nonspecific detection. Derivatization of formaldehyde by acetylacetone occurs under mild conditions and is specific for formaldehyde but it has not been investigated using high-performance liquid chromatography/tandem mass-spectrometry (HPLC/MS/MS).

METHODS

To determine formaldehyde, PCPs were dissolved and then interferences were minimized by graphitized-carbon solid-phase extraction. Formaldehyde was derivatized to 3,5-diacetyl-1,4-dihydrolutidine (DDL) using an acetylacetone solution. Post-derivatization, samples were diluted and analyzed by HPLC/MS/MS. Quantification was performed by isotopic dilution. Product-ion spectra were acquired for DDL and D₁₂ -DDL. The mass shifts between the two product-ion spectra were used to assign fragment structures. To confirm molecular formulas, high-resolution accurate-mass analysis of the DDL product ions was performed by quadrupole time-of-flight MS.

RESULTS

Structures were proposed for all product ions of DDL above 10% relative intensity. Method accuracy ranged between 96-104% for all matrices at all concentrations tested. Method precision was less than 4% relative standard deviation. The reporting limit was 10 ng/mg in PCPs and 100 μg/L in water. Twenty children's PCPs were tested to demonstrate the method and formaldehyde was reported in five from 23-1500 ng/mg. Of those five, two samples contained formaldehyde above the Minnesota regulatory limit.

CONCLUSIONS

The developed method allows for the accurate quantification of formaldehyde in PCPs at levels below those required by a new regulation on children's products in Minnesota. The method includes a derivatization procedure that is newly adapted to HPLC/MS/MS; therefore, structures were proposed for the product ions of the derivative (DDL). Copyright © 2017 John Wiley & Sons, Ltd.

Nail cosmetics in nail disorders

The clinical features of nail dystrophies depend on the part of the nail that has been damaged. Due to the important functions of fingernails and toenails, any abnormality of the nail causes impaired function of the hand or foot. Moreover, the aesthetic aspect of the nail may affect employability, self-esteem, and interaction with other people. Because the nails are often difficult to treat, cosmetology may be an effective support to medical treatment. Nail cosmetics may help the patient to cope with his or her nail dystrophy while waiting for treatment to show its efficacy. It may also be the only choice to hide nail dystrophy where the nail is irreversibly damaged. Nail cosmetics may also function at treatment for onychtillomania, nail biting, and nail ingrowing.

Contact and primary irritant dermatitis of the nail unit diagnosis and treatment

Contact dermatitis of the nail unit is not rare. The most common allergens are found in nail cosmetics such as enamel, sculptured nails, and preformed plastic tips. Toluene sulfonamide formaldehyde resin, acrylates, and ethylcyanoacrylate are the most common allergens. Along with a proper clinical history focusing on nail practices, a thorough understanding of the common allergens and patch testing are necessary to diagnose contact dermatitis. A discussion of the common allergens and irritants relevant to the nail unit will be presented.

Final report of the safety assessment of methacrylate ester monomers used in nail enhancement products

Methacrylate ester monomers are used in as artificial nail builders in nail enhancement products. They undergo rapid polymerization to form a hard material on the nail that is then shaped. While Ethyl Methacrylate is the primary monomer used in nail enhancement products, other methacrylate esters are also used. This safety assessment addresses 22 other methacrylate esters reported by industry to be present in small percentages as artificial nail builders in cosmetic products. They function to speed up polymerization and/or form cross-links. Only Tetrahydrofurfuryl Methacrylate was reported to the FDA to be in current use. The polymerization rates of these methacrylate esters are within the same range as Ethyl Methacrylate. While data are not available on all of these methacrylate esters, the available data demonstrated little acute oral, dermal, or i.p. toxicity. In a 28-day inhalation study on rats, Butyl Methacrylate caused upper airway irritation; the NOAEL was 1801 mg/m3. In a 28-day oral toxicity study on rats, t-Butyl Methacrylate had a NOAEL of 20 mg/kg/day. Beagle dogs dosed with 0.2 to 2.0 g/kg/day of C12 to C18 methacrylate monomers for 13 weeks exhibited effects only in the highest dose group: weight loss, emesis, diarrhea, mucoid feces, or salivation were observed. Butyl Methacrylate (0.1 M) and Isobutyl Methacrylate (0.1 M) are mildly irritating to the rabbit eye. HEMA is corrosive when instilled in the rabbit eye, while PEG-4 Dimethacrylate and Trimethylolpropane Trimethacrylate are minimally irritating to the eye. Dermal irritation caused by methacrylates is documented in guinea pigs and rabbits. In guinea pigs, HEMA, Isopropylidenediphenyl Bisglycidyl Methacrylate, Lauryl Methacrylate, and Trimethylolpropane Trimethacrylate are strong sensitizers; Butyl Methacrylate, Cyclohexyl Methacrylate, Hexyl Methacrylate, and Urethane Methacrylate are moderate sensitizers; Hydroxypropyl Methacrylate is a weak sensitizer; and PEG-4 Dimethacrylate and Triethylene Glycol Dimethacrylate are not sensitizers. Ethylene Glycol Dimethacrylate was not a sensitizer in one guinea pig study, but was a strong sensitizer in another. There is cross-reactivity between various methacrylate esters in some sensitization tests. Inhaled Butyl Methacrylate, HEMA, Hydroxypropyl Methacrylate, and Trimethylolpropane Trimethacrylate can be developmental toxicants at high exposure levels (1000 mg/kg/day). None of the methacrylate ester monomers that were tested were shown to have any endocrine disrupting activity. These methacrylate esters are mostly non-mutagenic in bacterial test systems, but weak mutagenic responses were seen in mammalian cell test systems. Chronic dermal exposure of mice to PEG-4 Dimethacrylate (25 mg, 2 x weekly for 80 weeks) or Trimethylolpropane Trimethacrylate (25 mg, 2 x weekly for 80 weeks) did not result in increased incidence of skin or visceral tumors. The carcinogenicity of Triethylene Glycol Dimethacrylate (5, 25, or 50%) was assessed in a mouse skin painting study (50 microl for 5 days/week for 78 weeks), but was not carcinogenic at any dose level tested. The Expert Panel was concerned about the strong sensitization and crossor co-reactivity potential of the methacrylate esters reviewed in this report. However, data demonstrated the rates of polymerization of these Methacrylates were similar to that of Ethyl Methacrylate and there would be little monomer available exposure to the skin. In consideration of the animal toxicity data, the CIR Expert Panel decided that these methacrylate esters should be restricted to the nail and must not be in contact with the skin. Accordingly, these methacrylate esters are safe as used in nail enhancement products when skin contact is avoided.

Cosmetic allergy: incidence, diagnosis, and management

A recent epidemiologic survey in the UK revealed that 23% of women and 13.8% of men experience some sort of adverse reaction to a personal care product over the course of a year. Although most of these reactions may be due to subjective sensory irritation, various studies reveal that up to 10% of dermatologic patients who are patch tested are allergic to cosmetic products or their constituent ingredients. Causative products include deodorants and perfumes, skin care products, hair care products, and nail cosmetics. Allergic contact dermatitis mainly results from fragrance chemicals and preservatives. Recent work has suggested that additional fragrance chemicals may need to be tested in order to identify those patients 'missed' by the current fragrance mix; in particular, hydroxy-isohexyl-3-cyclohexene carboxaldehyde (HMPPC Lyral) has been singled out as an important sensitizing agent. The increased usage of natural fragrances and botanic extracts can also cause problems in their own right or through co-reactivity. The preservative methyldibromo glutaronitrile has also been recognized as an increasingly important sensitizer in Europe, which has led to the recent recommendation that it should be prohibited from 'leave-on' products until information on 'safe' consumer levels becomes available. Other emerging allergens include UV filters, tosylamide/formaldehyde resin, and nail acrylates. The diagnosis of cosmetic allergy should be confirmed with patch testing, including testing of 'whole' products, when necessary, and repeat open application tests can be used to confirm the relevance of reactions in cases of doubt.

Minimizing patients' exposure to uncured components in a dental sealant

BACKGROUND

The authors conducted research to examine the effectiveness of six surface treatments in reducing the oxygen-inhibited layer of a commercially available, freshly polymerized, light-cured unfilled dental sealant.

METHODS

Surface treatments of a light-cured sealant (Delton Light Curing Pit & Fissure Sealant, Dentsply Ash) included no treatment (the control treatment), a 20-second exposure to an air/water syringe spray, 20 seconds' manual application of a wet or dry cotton roll, 20 seconds' manual application of pumice with a cotton pellet, and 20 seconds' application of a water/pumice slurry using a prophy cup on a slow-speed handpiece. The authors used high-pressure liquid chromatography to analyze the amount of monomers--bisphenol A glycidyl dimethacrylate, or Bis-GMA; triethylene glycol dimethacrylate, or TEGDMA; and bisphenol A dimethacrylate, or Bis-DMA--remaining after each treatment.

RESULTS

A one-way analysis of variance indicated that use of only an air/water spray removed the least (P = .0001) amount of all monomers (only 68.3 percent of the control value). Application of wet or dry cotton reduced equivalent amounts of monomers (86.1 to 88.9 percent of the control value), and the amount of monomer remaining was less than that for the air/water syringe treatment (P = .0001). The use of pumice on either a cotton ball or in a prophy cup achieved the greatest reduction (P = .0001) in total amount of residual monomer (92.9 to 95.3 percent of the control value).

CONCLUSIONS

Treatment that used pumice eliminated the greatest amount (from 93 percent to 95 percent of the untreated control values) of any type of residual monomer. A slurry of pumice is significantly more effective in removing the oxygen-inhibited layer from freshly cured sealants than either an air/water spray or wet or dry cotton alone.

CLINICAL IMPLICATIONS

Clinicians can most effectively reduce patients' exposure to the uncured components in the oxygen-inhibited layer of sealants by using a mild abrasive, such as pumice, either on a cotton applicator or in a prophy cup.