Formaldehyde-releasers: relationship to formaldehyde contact allergy. Part 2: Metalworking fluids and remainder.

We have reviewed formaldehyde-releasers used in metalworking fluids (MWFs) in this and a previous part of a two-part article. These biocides do not appear to be frequent or important sensitizers. Even in highly selected patient groups of metalworkers, mean prevalence rates of sensitivity are low: 0.2% for Tris(hydroxymethyl)nitromethane, 1.6% for tris(N-hydroxyethyl)hexahydrotriazine, 1.9% for Bioban P-1487 and Bioban CS-1246, and 2.8% for Bioban CS-1135. In the case of the Biobans, many reactions may have been irritant. Only N,N'-methylenebis(5-methyloxazolidine) has a fairly high mean score of 4.0% in metalworkers. With the exception of Bioban P-1487, there is a clear relationship between positive patch test reactions to the releasers and formaldehyde sensitivity: 40-70% of reactions to releasers occur in patients sensitive to formaldehyde and may therefore be caused by formaldehyde allergy. There is a lack of reliable data on the clinical relevance of contact allergy to the formaldehyde releasers in MWF. In most studies, no data on relevance were provided and in those that did, relevance was often found for a (very small) minority of the reactions only. Also discussed here are the formaldehyde-releasers MDM hydantoin, methenamine, N-methylolchloracetamide, paraformaldehyde, and Preventol D2.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Metalworking fluids and remainder. Part 1.

This is part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy. Formaldehyde-releasers used in metalworking fluids (MWF) and a group of releasers not presented in previous articles are discussed. Here, in Part 1 of the article, there is a short overview of the composition and functions of MWF, the function of biocides in them, and adverse reactions to MWF. In addition, the releasers in MWF that have caused contact allergy are presented with CAS, synonyms, molecular formula, chemical structure, applications, patch test studies, and amount of formaldehyde released by them. In Part 2 of the article, the relationship between formaldehyde-releasers used in MWF and formaldehyde contact allergy is discussed as are data on miscellaneous releasers not previously presented, followed by a discussion of Parts 1 and 2 of the article.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Formaldehyde-releasers in clothes: durable press chemical finishes. Part 1.

This is one of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy and in this paper formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles are discussed. The literature on allergy to DPCF since 1980 is presented in two parts. Part 1 (this article) presents a short historical overview of the problems with formaldehyde in clothes and discusses the chemistry of durable press chemical finishes, legislation in various countries, and studies on the amount of formaldehyde present in clothes. In addition, the DPCF that have caused contact allergy are presented with CAS, synonyms, molecular formula, chemical structure, applications, and patch test studies. In the forthcoming part 2, the frequency of sensitization to DPCF, occupational contact sensitization, relevance of patch test reactions, and relationship to formaldehyde contact allergy will be reviewed, followed by a discussion of both parts of the article together.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Part 2. Formaldehyde-releasers in clothes: durable press chemical finishes.

This is the second part of a review article on formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles. The early finishes contained large amounts of free formaldehyde, which led to many cases of allergic contact dermatitis to clothes in the 1950s and 1960s. Currently, most finishes are based on modified dimethylol dihydroxyethyleneurea, which releases less formaldehyde. Nevertheless, recent studies in the United States and Israel have identified patients reacting to DPCF, considered to have allergic contact reactions to clothes, either from formaldehyde released by the DPCF therein or from the DPCF per se (in patients negative to formaldehyde). However, all studies had some weaknesses in design or interpretation and in not a single case has the clinical relevance been proven. The amount of free formaldehyde in most garments will likely be below the threshold for the elicitation of dermatitis for all but the most sensitive patients. The amount of free cyclized urea DPCF in clothes is unlikely to be high enough to cause sensitization. Patch test reactions to formaldehyde-releasing DPCF will in most cases represent a reaction to formaldehyde released from the test material.

Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics.

In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetics. In Europe, low frequencies of sensitization have been observed to all releasers: 2-bromo-2-nitropropane-1,3-diol 0.4-1.2%, diazolidinyl urea 0.5-1.4%, imidazolidinyl urea 0.3-1.4%, quaternium-15 0.6-1.9% (for DMDM hydantoin no recent data are available). All releasers score (far) higher prevalences in the USA; the possible explanations for this are discussed. The relevance of positive patch test reactions has been insufficiently investigated. In the USA, approximately 20% of cosmetics and personal care products (stay-on products: 17%, rinse-off products 27%) contain a formaldehyde-releaser. The use of quaternium-15 is decreasing. For Europe, there are no comparable recent data available. In the second part of the article, the patch test relationship of the releasers in cosmetics to formaldehyde contact allergy will be reviewed and it will be assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals who have contact allergy to formaldehyde.

Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 2. Patch test relationship to formaldehyde contact allergy, experimental provocation tests, amount of formaldehyde released, and assessment of risk to consumers allergic to formaldehyde.

This is the second part of an article on formaldehyde-releasers in cosmetics. The patch test relationship between the releasers in cosmetics to formaldehyde contact allergy is reviewed and it is assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals with contact allergy to formaldehyde. There is a clear relationship between positive patch test reactions to formaldehyde-releasers and formaldehyde contact allergy: 15% of all reactions to 2-bromo-2-nitropropane-1,3-diol and 40-60% of the reactions to the other releasers are caused by a reaction to the formaldehyde in the test material. There is only fragmented data on the amount of free formaldehyde in cosmetics preserved with formaldehyde donors. However, all releasers (with the exception of 2-bromo-2-nitropropane-1,3-diol, for which adequate data are lacking) can, in the right circumstances of concentration and product composition, release >200 p.p.m. formaldehyde, which may result in allergic contact dermatitis. Whether this is actually the case in any particular product cannot be determined from the ingredient labelling. Therefore, we recommend advising patients allergic to formaldehyde to avoid leave-on cosmetics preserved with quaternium-15, diazolidinyl urea, DMDM hydantoin, or imidazolidinyl urea, acknowledging that many would tolerate some products.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers.

This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allergy are reviewed: applications, exposure scenarios, legislation, patch testing problems, frequency of sensitization, relevance of positive patch test reactions, clinical pattern of allergic contact dermatitis from formaldehyde, prognosis, threshold for elicitation of allergic contact dermatitis, analytical tests to determine formaldehyde in products and frequency of exposure to formaldehyde and releasers. The frequency of contact allergy to formaldehyde is consistently higher in the USA (8-9%) than in Europe (2-3%). Patch testing with formaldehyde is problematic; the currently used 1% solution may result in both false-positive and false-negative (up to 40%) reactions. Determining the relevance of patch test reactions is often challenging. What concentration of formaldehyde is safe for sensitive patients remains unknown. Levels of 200-300 p.p.m. free formaldehyde in cosmetic products have been shown to induce dermatitis from short-term use on normal skin.

Airborne irritant contact dermatitis and conjunctivitis after occupational exposure to chlorothalonil in textiles.

Chlorothalonil (tetrachloro-1,3-benzenedicarbonitrile, CAS 1897-45-6) is a pesticide that has been on the market for many years. It is used as a fungicide in agriculture, horticulture, and floriculture; as a wood preservative; and in paint. We report an epidemic of airborne irritant contact dermatitis, conjunctivitis, and upper airway complaints among seamstresses in a Portuguese trailer tent factory, which we attribute to chlorothalonil. All exposed workers had work-related skin symptoms. After patch testing, we showed that none of these were of allergic origin. Instead of allergic reactions, we noticed a delayed type of irritation after 72 hr to chlorothalonil and to the textile extracts containing high concentrations of chlorothalonil. Although allergic and irritant contact dermatitis from chlorothalonil has been described before, this is, as far as we know, the first time that a delayed type of dermatitis, conjunctivitis, and upper airway irritation after exposure to chlorothalonil in tent-cloth is described.