Adverse cutaneous reactions to cosmetic allergens

Sulfites

The Expert Panel for Cosmetic Ingredient Safety reviewed newly available studies since their original assessment in 1998, along with updated information regarding product types and concentrations of use, and confirmed that Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are safe as cosmetic ingredients in the practices of use and concentration as described in this report.

Lipid Nanomaterials for Targeted Delivery of Dermocosmetic Ingredients: Advances in Photoprotection and Skin Anti-Aging

Despite the health benefits of the sun, overexposure to solar radiation without proper precautions can cause irreversible damage to exposed skin. In the search for balance between the risks and benefits of exposure to solar radiation in human health, a technological alternative was found, the incorporation of photoprotective products in lipid nanoparticulate systems for topical application. These nanometric systems have demonstrated several advantages when used as adjuvants in photoprotection compared to chemical and/or physical sunscreens alone. The increase in the sun protection factor (SPF), photostability and UV action spectrum are parameters that have benefited from the application of these systems in order to increase the effectiveness and safety of photoprotective formulations containing organic and/or inorganic sunscreens.

Patch Testing with Ammonium Persulfate: The North American Contact Dermatitis Group Experience, 2015-2018

BACKGROUND

Ammonium persulfate (APS), an oxidizing agent used in hair products, manufacturing, and pool/spa water, can cause skin reactions including allergic contact dermatitis.

OBJECTIVE

To characterize positive patch test reactions to APS (2.5% pet).

METHODS

Retrospective analysis of patients tested to the North American Contact Dermatitis Group (NACDG) screening series from 2015-2018.

RESULTS

Of 10,526 patients, 193 (1.8%) had positive patch test reactions to APS. Compared to negative patients, APS-positive patients were significantly more likely to be male (43.2% vs. 28.0%, p<0.0001), have primary hand (30.2% vs. 22.0%, p=0.0064), scattered generalized (25.5% vs. 17.9%, p=0.0064), or trunk dermatitis (8.9% vs. 4.9%, p=0.0123), and occupationally-related dermatitis (22.2% vs. 10.9%, p<0.0001). Over half of the APS-positive reactions were currently relevant (57.0%); 19 (9.8%) were related to occupation, especially (68.4%) hairdressers. Swimming pools/spas (23.3%) and hair care products (19.2%) were the most common APS sources.

LIMITATIONS

Immediate reactions and follow-up testing not captured.

CONCLUSIONS

The proportion of patients positive to APS was 1.8%. APS positivity was significantly associated with male sex and hand dermatitis. Swimming pool/spa chemicals are important sources of APS exposure.

Safety Assessment of Sorbitan Esters as Used in Cosmetics

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 20 sorbitan esters; this report included sorbitan esters that were reviewed in 1985 and 2002, as well as 3 previously unreviewed sorbitan esters (sorbitan undecylenate, sorbitan sesquicaprylate, and sorbitan palmate). Most of the sorbitan esters are reported to function in cosmetics as surfactant-emulsifying agents. The Panel reviewed the data from previous sorbitan ester reports, as well as additional data included in this report, to determine the safety of these ingredients. The Panel concluded that the sorbitan esters included in this safety assessment are safe in cosmetics in the present practices of use and concentration.

Stratum corneum substantivity: drug development implications

There are at least 15 factors that influence the ability of chemicals to penetrate the skin. Substantivity is yet another factor and allows penetrants to remain on and in skin for many days. As many skin pathologies involve stratum corneum and require multiple dosing of topicals, understanding substantivity mechanisms may provide insight for topical dosing strategies. Substantivity is also of importance in the development of other consumer products that necessitate adherence to skin, including sunscreens, insect repellents, and cosmetics. Furthermore, while stratum corneum adherence may delay percutaneous penetration, reducing the risk of systemic toxicity, excessive substantivity may play a role in the toxic accumulation of harmful penetrants. Continued research in this area may offer insight into dermatotoxicology and dermatopharmacology.

Safety Assessment of Methyl Glucose Polyethers and Esters as Used in Cosmetics

The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of methyl glucose polyethers and esters which function in cosmetics as skin/hair-conditioning agents, surfactants, or viscosity increasing agents. The esters included in this assessment are mono-, di-, or tricarboxyester substituted methyl glucosides, and the polyethers are mixtures of various chain lengths. The Panel reviewed available animal and clinical data, including the molecular weights, log K_ows, and other properties in making its determination of safety on these ingredients. Where there were data gaps, similarities between molecular structures, physicochemical and biological characteristics, and functions and concentrations in cosmetics allowed for extrapolation of the available toxicological data to assess the safety of the entire group. The Panel concluded that there likely would be no significant systemic exposure from cosmetic use of these ingredients, and that these ingredients are safe in cosmetic formulations in the present practices of use and concentration.

Antimicrobial films containing microparticles for the enhancement of long-term sustained release

Coated packagings with thin films containing antimicrobial agents are an alternative technology to ensure the protection of products against microbial contaminations. Indeed, they allow lowering the antimicrobial concentration in the bulk of the product while meeting the safety requirements and the growing consumer demand for low preservative concentrations. Microencapsulation is a suitable way for controlling active agent release and providing a long-term activity. This work aims at combining both technical solutions with coatings containing antimicrobial microparticles for the achievement of long-term sustained release. Polyethylene surfaces were functionalized with microparticles of poly(methyl methacrylate) (PMMA) loaded with phenylethyl alcohol (PEA) as antimicrobial agent by the dip coating process using a polyurethane binder. The release of PEA into water from coated polyethylene surfaces and from PMMA microparticles was investigated to assess the sustained release and its mechanisms. Films with various thicknesses of 400-1000 µm containing antimicrobial microparticles demonstrated unusual long-term release longer than 3 months. The diffusion of the antimicrobial agent through PMMA was the rate limiting step of the sustained release. PEA release increased as the contact area of the protruding microparticles with the external medium increased and the thickness of the film decreased. Such antimicrobial agents encapsulated inside thin coatings are promising with regards to antimicrobial preservation of products along their full shelf-life.

Occurrence of eight UV filters in beaches of Gran Canaria (Canary Islands). An approach to environmental risk assessment

Due to the growing concern about human health effects of ultraviolet (UV) radiation, the use of UV filters has increased in recent decades. Unfortunately, some common UV filters are bioaccumulated in aquatic organisms and show a potential for estrogenic activity. The aim of the present study is to determine the presence of some UV filters in the coastal waters of six beaches around Gran Canaria Island as consequence of recreational seaside activities. Eight commonly used UV filters: benzophenone-3 (BP-3), octocrylene (OC), octyl-dimethyl-PABA (OD-PABA), ethylhexyl methoxy cinnamate (EHMC), homosalate (HMS), butyl methoxydibenzoyl methane (BMDBM), 4-methylbenzylidene camphor (4-MBC) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB), were monitored and, with the exception of OD-PABA, all were detected in the samples collected. 99% of the samples showed some UV filters and concentration levels reached up to 3316.7 ng/L for BP-3. Environmental risk assessment (ERA) approach showed risk quotients (RQ) higher than 10, which means that there is a significant potential for adverse effects, for 4-MBC and EHMC for those samples with highest levels of UV filters.

A new protocol for evaluating the efficacy of some dispensing systems of a packaging in the microbial protection of water-based preservative-free cosmetic products

OBJECTIVE

A new protocol is described for assessing the efficacy of the dispenser of some packaging systems (PSs) of preservative-free cosmetic products in protecting both their contained formula and their delivered doses.

METHODS

Practically, aiming at mimicking contacts with a non-sterile skin or fingers, the dispensing system is put into contact with a pre-contaminated fabric by a standardized colonization of P. aeruginosa.

RESULTS

When applied to three different types of packaging, results show clear differences in both criteria between these conditioning articles, that is variable efficacies in protecting the contained product and the delivered doses, knowing that the first aspect is of paramount importance.

CONCLUSION

The proposed protocol is proved being able to discriminate between different PSs and provides information on strong and weak features of certain types dispensing technologies prone to efficiently decrease either the dose contamination or to prevent contamination in reaching the contained product. Therefore, the proposed protocol can contribute to an objective selection of a PS for protecting a cosmetic care product with a low content of preservative or preservative free.

Contact Allergies to Cosmetics: Testing with 52 Cosmetic Ingredients and Personal Products

Fifty patients of both sexes with clinically suspected cosmetic dermatitis were subjected to patch testing with a cosmetic and fragrance series, approved by the Contact and Occupational Dermatosis Forum of India (CODFI), and with selected allergens from the Indian Standard Series (ISS). Most of these patients were young adults between 10-29 years; the mean age was 27.5 years. The majority of the patients had cosmetic dermatitis of <1 year duration (68%). The occupational profiles of the patients included students (46%), housewives (18%), teachers (10%) and laborers (4%). A miscellaneous group, comprised of tailors, farmers, staff nurses, beauticians, jewellers and engineers, accounted for the remaining 22%. The most commonly involved site was the face, followed by the forehead, neck and scalp. Patch testing of these patients revealed that, out of the 50 subjects tested, thirty-three (66%) reacted to one or more allergens. Fragrance components were the most common offending allergen (51.5%) followed by preservatives (39.3%), paraphenylenediamine (PPD) (21.2%), and cetrimide and tertiary butyl hydroquinone (12.1% each), in descending order of frequency. Hence, patch testing, with the standard series supplemented by personal cosmetics; should be considered for patients with cosmetic dermatitis to determine the offending allergen so as to avoid further contact with that allergen.

Allergic contact dermatitis to fragrances. Part 1

Fragrances are a large group of substances and the second most common cause of allergic contact dermatitis in Spain. These potential allergens are extremely common and the general population is subject to continuous exposure on a daily basis. While the fragrance markers included in the current Spanish standard patch test series are good, there is room for improvement. New markers that have emerged in recent years have proven to be of value in standard series used in other countries. Diagnosing fragrance allergy has taken on even greater importance since the European Union added 26 fragrances to its list of mandatory ingredients to be specified on product labels. The aim of this review is to provide an update on allergic contact dermatitis to fragrances. We examine the main sources of exposure and clinical manifestations of this condition and propose a diagnostic and treatment protocol.

Safety Assessment of Alkyl PEG Ethers as Used in Cosmetics

The CIR Expert Panel assessed the safety of Alkyl PEG Ethers as used in cosmetics. These ingredients primarily function in cosmetics as surfactants, and some have additional functions as skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Panel reviewed available relevant animal and clinical data, as well as information from previous CIR reports; when data were not available for individual ingredients, the Panel extrapolated from the existing data to support safety. The Panel concluded that the Alkyl PEG ethers are safe as used when formulated to be nonirritating, and the same applies to future alkyl PEG ether cosmetic ingredients that vary from those ingredients recited herein only by the number of ethylene glycol repeat units.

Allergic contact dermatitis: immune system involvement and distinctive clinical cases

The aim of this review is drawing the attention to the contact dermatitis, an inflammatory skin condition due to pro-inflammatory and toxic factors able to activate the skin innate immunity (irritant contact dermatitis) or caused by a T-cell- mediated hypersensitivity reaction (allergic contact dermatitis). The immune system involvement and a variety of clinical pictures are described in order to better diagnose, prevent and treat allergic contact dermatitis.

Low-level efficacy of cosmetic preservatives

Preservation using combinations of preservatives has several advantages. This study shows that the concentration of some of the most frequently used allergenic preservatives can be markedly lowered when they are combined with phenoxyethanol. The antimicrobial efficacy of cosmetic preservatives and known allergens of various potency [diazolidinyl urea, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), methylisothiazolinone (MI) and phenoxyethanol] was tested alone and in various combinations of two or three preservatives together. The preservatives were tested for minimum inhibitory concentration (MIC) values and possible synergy using fractional inhibitory concentration. MCI/MI was the only preservative showing low-level MIC against all four tested microorganisms: Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Different combinations of the preservatives indicated additive effects against the microorganisms. No combination of preservatives showed any inhibitory action on each other. Challenge tests with different concentrations and combinations were performed in a cosmetic cream. Diazolidinyl urea and MCI/MI alone were ineffective against C. albicans in a challenge test at concentrations up to 16 times higher than the observed MIC values. When combining phenoxyethanol with either one of the allergenic preservatives diazolidinyl urea, MCI/MI or MI, the cosmetic cream was adequately preserved at concentrations well below the preservatives' MIC values as well as 10-20 times below the maximum permitted concentrations. By using combinations of preservatives, effective preservation can be achieved with lower concentrations of allergenic preservatives.

Comparison of Marketed Cosmetic Products Constituents with the Antigens Included in Cosmetic-related Patch Test

BACKGROUND

Currently, cosmetic series (Chemotechnique Diagnostics, Sweden) is the most widely used cosmetic-related patch test in Korea. However, no studies have been conducted on how accurately it reflects the constituents of the cosmetics in Korea.

OBJECTIVE

We surveyed the constituents of various cosmetics and compare with the cosmetic series, to investigate whether it is accurate in determining allergic contact dermatitis caused by cosmetics sold in Korea.

METHODS

Cosmetics were classified into 11 categories and the survey was conducted on the constituents of 55 cosmetics, with 5 cosmetics in each category. The surveyed constituents were classified by chemical function and compared with the antigens of cosmetic series.

RESULTS

155 constituents were found in 55 cosmetics, and 74 (47.7%) of constituents were included as antigen. Among them, only 20 constituents (27.0%) were included in cosmetic series. A significant number of constituents, such as fragrance, vehicle and surfactant were not included. Only 41.7% of antigens in cosmetic series were found to be in the cosmetics sampled.

CONCLUSION

The constituents not included in the patch test but possess antigenicity are widely used in cosmetics. Therefore, the patch test should be modified to reflect ingredients in the marketed products that may stimulate allergies.

Final Amended Report on the Safety Assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl Thioglycolate, Glyceryl Thioglycolate, Isooctyl Thioglycolate, Isopropyl Thioglycolate, Magnesium Thioglycolate, Methyl Thioglycolate, Potassium Thioglycolate, Sodium Thioglycolate, and Thioglycolic Acid

This safety assessment includes Ammonium and Glyceryl Thioglycolate and Thioglycolic Acid Butyl, Calcium, Ethanolamine, Ethyl, Isooctyl, Isopropyl, Magnesium, Methyl, Potassium, and Sodium Thioglycolate, as used in cosmetics. Thioglycolates penetrate skin and distribute to the kidneys, lungs, small intestine, and spleen; excretion is primarily in urine. Thioglycolates were slightly toxic in rat acute oral toxicity studies. Thioglycolates are minimal to severe ocular irritants. Thioglycolates can be skin irritants in animal and in vitro tests, and can be sensitizers. A no-observable-adverse-effect level for reproductive and developmental toxicity of 100 mg/kg per day was determined using rats. Thioglycolates were not mutagenic, and there was no evidence of carcinogenicity. Thioglycolates were skin irritants in some clinical tests. Clinically significant adverse reactions to these ingredients used in depilatories are not commonly seen, suggesting current products are formulated to be practically nonirritating under conditions of recommended use. Formulators should take steps necessary to assure that current practices are followed.

Human health risk assessment of long chain alcohols

Representative chemicals from the long chain alcohols category have been extensively tested to define their toxicological hazard properties. These chemicals show low acute and repeat dose toxicity with high-dose effects (if any) related to minimal liver toxicity. These chemicals do not show evidence of activity in genetic toxicity tests or to the reproductive system or the developing organism. These chemicals also are not sensitizers. Irritation is dependant on chain length; generally, alcohols in the range C(6-)C(11) are considered as irritant, intermediate chain lengths (C(12-)C(16)) alcohols are considered to be mild irritants and chain lengths of C(18) and above are considered non-irritants. These chemicals are broadly used across the consumer products industry with highest per person consumer exposures resulting from use in personal care products. Margins of exposure adequate for the protection of human health are documented for the uses of these chemicals.

Allergic patch test reactions associated with cosmetics: retrospective analysis of cross-sectional data from the North American Contact Dermatitis Group, 2001-2004

BACKGROUND

Allergy to cosmetics is common.

OBJECTIVES

We sought to characterize patients with positive patch test reactions associated with a cosmetic source, to identify common allergens; and to explore gender and occupational associations.

METHODS

We performed a retrospective, cross-sectional analysis.

RESULTS

Of 6621 female and 3440 male patients, 1582 female (23.8%) and 611 of male (17.8%) patients had at least one allergic patch test reaction associated with a cosmetic source. Of "allergic" patients (>1 allergic reaction, n = 6815), females were 1.21 times more likely to have an allergic reaction associated with a cosmetic source than were male patients (p < .0001, 95% confidence interval [CI] 1.12-1.31). Within the "cosmetic allergic" group (n = 2243), head and neck involvement was significantly higher in female than in male patients (49.3% vs 23.7%, p < .0001). One hundred twenty-five patients had occupationally related allergic reactions associated with a cosmetic.

LIMITATIONS

This study is limited by its cross-sectional, retrospective design.

CONCLUSION

Of all patients studied, 21.8% had an allergic reaction associated with a cosmetic. Site of dermatitis, cosmetic categories, and specific allergens differed somewhat by gender.

Percutaneous absorption of organic sunscreens

The increased awareness of protection against skin cancer has led to a rise in the use of topically applied chemical sunscreen agents. There is a concern about the systemic absorption of organic filters in sunscreen formulations. The present study briefly reviews theoretical models for the prediction of the percutaneous penetration of the organic molecules and the accepted methods for the in vitro and in vivo evaluations of the penetration. The influence of the vehicle and the formulation viscosity on the penetration of sunscreens are examined. The development of novel methods for the minimization of sunscreen absorption is also discussed.

Preservatives sensitivity in Israel: a 10-year overview (1995?2004)

This study presents a 10-year survey of 2285 patients tested to common preservatives in northern Israel. The demographic and clinical data were analysed using a revised MOAHLFA index. Patch testing was based on the International Contact Dermatitis Research Group (ICDRG) guidelines. 411 (18%) patients were found to have positive reactions to 1 or more preservatives. The most frequent allergens tested positively were thimerosal, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), and formaldehyde. The reactions to MCI/MI remained stable around 1.7% throughout the years 1995-1998, with a significant increase to 3.7%-4% (P = 0.029) during 1999-2004. The reactions to formaldehyde remained low around 0.3% until 1999; however, a considerable increase throughout the years 2000-2004 was noted, with rates of 1.5%-1.9% (P = 0.028). The sensitivity rates for parabens, quaternium-15, imidazolidinylurea, and diazolidinylurea were low and unchanged, mostly under 0.5%. As for methyldibromoglutaronitrile (MDBGN), sensitivity rates around 2% were detected for the years 1996 and throughout 2000-2004. Overall, this extensive survey showed a concerning increase in the sensitivity rates for MCI/MI, formaldehyde, and MDBGN.

Allergic Contact Dermatitis to Cosmetics

Cosmetics are used to enhance one's appearance and are used by women worldwide. This article reviews the epidemiology, clinical features, and management of cosmetic allergic contact dermatitis. Additionally, several important cosmetic-related allergens are discussed.

Patch test reactions to cosmetic allergens in 1995-1997 and 2000-2002 in Finland - a multicentre study

Contact sensitivity to cosmetics is common, but the sensitizing chemicals vary between countries and study periods. The present survey aimed at revealing the recent trends in patch test sensitivity with cosmetic chemicals in Finland. We report a retrospective multicentre survey of patch test reactions focusing on cosmetic-related substances and comparing the test results in 1995-97 with those in 2000-02. The most striking increases in the frequency of the patch test sensitivity were found with balsam of Peru and propolis from 4.0% to 6.2% (P < 0.001) and from 0.5% to 1.4% (P < 0.001), respectively, whereas the most prominent decreases were found with methylchloro/methylisothiazolinone and chlorhexidine diglugonate from 2.4% to 1.3% (P < 0.001) and from 1.2% to 0.5% (P < 0.001), respectively. The level of patch test sensitivity to methyldibromo glutaronitrile increased, although not significantly, from 1.0% to 1.5%. An increasing tendency was also found with hair dye chemicals 4-aminophenol and toluene-2,5-diamine or toluene-2,5-diamine sulfate from 1.3% to 3.8% and from 1.4% to 5.2%, respectively, while such a tendency was not found among permanent wave chemicals. The sensitivity level of fragrance mix remained the same (6% - 7%). We conclude that surveys revealing the state of sensitivity to cosmetic chemicals should be performed periodically in different countries.

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.

Contact sensitization from Compositae-containing herbal remedies and cosmetics

The Compositae (Asteraceae) family of plants is currently an important cause of allergic plant contact dermatitis in Europe. The family comprises some of the oldest and most valued medicinal plants, and the increasing popularity of herbal medicine and cosmetics may theoretically result in a growing number of Compositae sensitizations from these sources. According to the literature at least 15 species, including among others arnica (Arnica montana), German and Roman chamomile (Chamomilla recutita and Chamaemelum nobile), marigold (Calendula officinalis), Echinacea and elecampane (Inula helenium), have been suspected of sensitization or elicitation of Compositae dermatitis. Epidemiological data are available for 2 species only, arnica and German chamomile, the rest of the evidence being anecdotal. Based on this, sensitization seems to occur relatively frequently with a few species such as arnica and elecampane, and occurs rarely with the majority, especially the widely used German chamomile. Sesquiterpene lactones are the most important allergens, but there are a few cases of sensitization from a coumarin, a sesquiterpene alcohol and a thiophene. The risk of elicitation of dermatitis by using Compositae-containing products in Compositae-sensitive individuals is by-and-large unknown.

Solid lipid nanoparticles as carrier for sunscreens: in vitro release and in vivo skin penetration

The aim of this study was the comparison of two different formulations (solid lipid nanoparticles (SLN) and conventional o/w emulsion) as carrier systems for the molecular sunscreen oxybenzone. The influence of the carrier on the rate of release was studied in vitro with a membrane-free model. The release rate could be decreased by up to 50% with the SLN formulation. Further in vitro measurements with static Franz diffusion cells were performed. In vivo, penetration of oxybenzone into stratum corneum on the forearm was investigated by the tape stripping method. It was shown that the rate of release is strongly dependent upon the formulation and could be decreased by 30-60% in SLN formulations. In all test models, oxybenzone was released and penetrated into human skin more quickly and to a greater extent from the emulsions. The rate of release also depends upon the total concentration of oxybenzone in the formulation. In vitro-in vivo correlations could be made qualitatively.

Monitoring levels of preservative sensitivity in Europe. A 10-year overview (1991-2000)

A 10-year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re-evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave-on products.

Preservation of products with MCI/MI in Switzerland

Preservation of products with the combination of 5-chloro-2-methyl-4-isothiazolinone (methylchloroisothiazolinone, MCI) and 2-methyl-4-isothiazolinone (methylisothiazolinone, MI), commercialized as Kathon CG or WT, is widely used. Allergic contact dermatitis reactions to the preservative have been described in many publications of epidemiological studies. In addition, a number of allergic, airborne reactions to MCI/MI were observed in recent years. The aim of the presented study was: (i) to compare epidemiological data of MCI/MI with data of other preservatives; (ii) to estimate the possible exposure to MCI/MI from commercial products and the distribution of MCI/MI in chemical products based on a product evaluation of the chemical product register of the Swiss Federal Office of Public Health; (iii) to estimate the exposure to MCI/MI, volatile organic chemicals (VOC) and glycols from freshly painted walls; (iv) to compare the contact allergenic potential of MCI/MI with other preservatives. It was found that the number of registered chemical products, unambiguously identifiable as containing MCI increased from 3644 products in July 1999 to 4843 products in April 2001 in Switzerland. It is estimated that today, the total number of chemical products preserved with MCI/MI on the Swiss market is about 6000. A further increase is to be expected. The contact allergenic potential of MCI/MI seems to be higher than for other preservatives. Measurements of MCI/MI concentrations in air samples of freshly painted rooms have shown that the concentration of MCI/MI in the air a few days after painting may be high enough to elicit airborne reactions in already-sensitized patients. In a single case, reactions to MCI/MI were observed over months after wall painting. In this case, both wall paint and plaster contained MCI (40 and 46 ppm). Volatile organic chemicals (VOC) may also be relevant for the elicitation of airborne reactions. In 1/3 of the measurements, the VOC concentrations measured within 14 days after painting were in a range within which sensory irritation and discomfort may be induced. Declaration of MCI/MI-containing products, replacement of MCI/MI by alternative preservatives or the separate use of preservatives in industrial products and in cosmetics might reduce the risk of airborne reactions.