Release of thiurams and carbamates from rubber gloves

Making Glove Decision Less of a White Knuckling Experience: A Systematic Review and Inventory of Glove Accelerator Contents

Background

Accelerators in medical gloves are a common cause of allergic contact dermatitis among healthcare workers.

Objective

A systematic review of medical and nursing literature, patch testing reports, and chemical analyses of gloves was conducted to assess accelerator contents reported in the literature and to identify accelerator-free gloves.

Methods

A systematic literature search was performed in OVID Medline and OVID EMBASE. Hand-searching of reference lists of articles in the field and author input generated the remainder of articles assessed.

Results

We present an inventory of accelerator contents of gloves and accelerator-free glove options as reported in the literature as a clinical reference tool to assist allergen-free glove selection for individuals suffering from allergic contact dermatitis due to rubber accelerators.

Limitations

Pertinent limitations of our review include lack of predefined study exclusion criteria and screening of the studies identified in the search by 1 review author only.

Conclusion

The glove inventory we provide summarizes the available literature regarding medical and surgical glove accelerator content, describing gloves both by brand and manufacturer as well as by accelerators.

Using passive sampling and zebrafish to identify developmental toxicants in complex mixtures

Using effects-directed analysis, we investigated associations previously observed between polycyclic aromatic hydrocarbons (PAHs) and embryotoxicity in field-deployed low-density polyethylene (LDPE). We conducted effects-directed analysis using a zebrafish embryo assay and iterative fractionation of extracts of LDPE that were deployed in the Portland Harbor superfund megasite, Oregon (USA). Whole extracts induced toxicity including mortality, edema, and notochord distortion at 20% effect concentration (EC20) values of approximately 100, 100, and 10 mg LDPE/mL, respectively. Through fractionation, we determined that PAHs at concentrations similar to previous research did not contribute markedly to toxicity. We also eliminated pesticides, phthalates, musks, and other substances identified in toxic fractions by testing surrogate mixtures. We identified free fatty acids as lethal components of LDPE extracts and confirmed their toxicity with authentic standards. We found chromatographic evidence that dithiocarbamates are responsible for notochord and other sublethal effects, although exact matches were not obtained. Fatty acids and dithiocarbamates were previously unrecorded components of LDPE extracts and likely contribute to the toxicity of the whole mixture. The present study demonstrates the success of effects-directed analysis in nontargeted hazard identification using the zebrafish embryo test as a self-contained battery of bioassays that allows identification of multiple chemicals with different modes of action. This is the first effects-directed analysis to combine LDPE and zebrafish, approaches that are widely applicable to identifying developmental hazards in the bioavailable fraction of hydrophobic organic compounds. Environ Toxicol Chem 2017;36:2290-2298. © 2017 SETAC.

[Contact allergies in the German workforce : Data of the IVDK network from 2003-2013]

BACKGROUND

In Germany, occupational skin diseases rank first in the occupational skin disease statistics for many years. Especially, occupationally acquired contact allergies as well as multi-sensitization are the most important predictors for a poor prognosis and persistent eczema.

OBJECTIVES

To update the spectrum and sensitization frequencies of most frequent allergens from the standard series in Germany in patients with occupationally acquired type IV sensitizations in general and within different occupational groups.

METHODS

Data of all employed patients (age range: 16-68 years, n = 14234) patch tested between 2003 and 2013 in the German Departments of the Information Network of Departments of Dermatology (IVDK) and diagnosed occupationally acquired contact dermatitis after patch testing were analyzed. The control group was composed of all other patients (n = 31706) within the same time frame, in which occupationally acquired allergic contact dermatitis was negated explicitly.

RESULTS

The prevalence Ratio (PR; indicating risk) was significantly increased for: Thiuram-mix (PR 5.63 95 %CI 4.97-6.4), zinkdiethyldithiocarbamate (PR 6.22 95 %CI 4.76-8.22), mercaptobenzothiazole (MBT) (PR 3.88 95 %CI 3.09-4.89), mercapto-mix without MBT (PR 3.23 95 %CI 2.59-4.03), N-isopropyl-N'-phenyl-p-phenylene diamine (IPPD) (PR 2.3195 %CI 1.87-2.86), epoxy resin (PR 2.82 95 %CI 2.45-3.25), chloromethylisothiazolinone/methylisothiazolinone (MCI/MI) (PR 2.19 95 %CI 1.97-2.42) and compositae mix II (PR 2.05 95 %CI 1.45-2.89). They were the predominant occupational allergens and were at least associated with a doubled risk (PR ≥ 2.0) for acquiring occupationally allergic contact dermatitis. The highest risk increase was identified in employees in the health services, in agriculture, metal industry, food and service industry as well as building trades

CONCLUSIONS

A limited number of occupationally relevant allergens cause the majority of sensitizations in the workforce, if standard series allergens are concerned. Data analysis of national and international contact allergy data bases provide valuable information on sensitization rates and profiles in skin risk occupations to implement targeted prevention strategies. To diagnose occupational allergic contact dermatitis in individual cases additional testing of occupation related patch test series as well as patients' own products is commonly inevitable.

Contact dermatitis in the cleaning industry

PURPOSE OF REVIEW

The review summarizes recent findings on contact dermatitis in the cleaning industry.

RECENT FINDINGS

Contact dermatitis is still an important issue in cleaning. Recent studies identified cleaning work sites and tasks, as well as specific cleaning products, which incur a risk increase for occupational contact dermatitis in cleaning. Workers involved in cleaning outdoors prevalence ratio [PR 1.85, 95% confidence interval (CI) 1.16-2.96], cleaning common areas of residential buildings (PR 1.77, 95% CI 1.11-2.84), schools (PR 1.84, 95% CI 1.15-2.93) and cleaning building sites (PR 1.87, 95% CI 1.18-2.95) showed significantly higher rates of contact dermatitis. Relevant allergens in cleaning are rubber chemicals and disinfectants. Leading allergens are thiurams (11.6%, 95% CI 9.1-14.1) and formaldehyde (3.4%, 95% CI 2.0-4.7), but contact with metal allergens might also be important. The most likely allergen sources for sensitization against rubber chemicals are protective gloves. High sensitization rates for disinfectants might result from the fact that employees in cleaning often use single-use medical examination gloves while cleaning. These gloves are not resistant to chemicals, which may break through the gloves within a short period of time, depending on glove material and thickness. No differences in sensitization rates and sensitization profiles were seen in cleaners of younger (≤40 years) and older (>40 years) age.

SUMMARY

Prevalence of occupational contact dermatitis is still high in cleaning. Irritant contact dermatitis is prevailing, but allergic contact dermatitis is quite frequent, too. Up to now, prevention strategies in cleaning seem to be insufficient.

Fundamentals of the knowledge about chemical additives present in rubber gloves

BACKGROUNDS

One of the most frequent causes of allergic contact dermatitis of occupational origin are rubber additives, which are present in Personal Protective Equipment (PPE). The most allergenic additives of natural and synthetic gloves are thiurams, carbamates and mercapto group.

OBJECTIVE

To investigate the state of knowledge about the chemical additives used in the manufacture of synthetic rubber gloves.

METHODS

This was a qualitative research study in which professionals working in the manufacture, research, prescription and commercialization of gloves answered an open questionnaire.

RESULTS

30 individuals were interviewed: 4 researchers in occupational medicine, 5 occupational physicians, 2 occupational safety technicians, a rubber workers' union physician, an occupational safety engineer, a pro duction engineer of rubber gloves, 4 importers of gloves, a manufacturer of gloves, 3 businessmen who sell PPE, 3 salesclerks working in stores that sell PPE, 2 businessmen who own stores that sell products for allergic individuals, and 3 dermatologists.

CONCLUSION

Knowledge of the chemical composition of rubber gloves is scant. The labeling of gloves, with the description of their chemical composition, would facilitate choosing the best type of glove for each person. This low-cost action to businesses would be a gain from the standpoint of public health, with huge repercussions for users of rubber gloves.

Effect of diet with thiram on liver antioxidant capacity and tibial dyschondroplasia in broilers

1. An experiment was conducted to study the effect of thiram on liver antioxidant capacity and incidence of tibial dyschondroplasia in broilers. 2. One hundred and twenty Avian commercial broilers were allotted at random to three treatments: control group, low thiram group (50 mg/kg) and high thiram group (100 mg/kg). 3. Blood samples were collected to determine the activity of AST (aspartate aminotransferase). At the end of the trial, broilers were killed and liver samples were collected to determine the activity of SOD (superoxide dismutase), GSH-Px (glutathione peroxidase) and MDA (malondialdehyde) content, while the right proximal tibiotarsi were dissected in longitudinal section for assessment of tibial dyschondroplasia (TD) incidence and TD score. 4. The results showed that thiram increased the incidence of TD and TD scores, increased serum AST activity and MDA content of liver, and decreased the activity of SOD and GSH-Px in the liver. 5. They suggest that thiram causes TD in broilers by reducing liver antioxidation capability and damaging liver function; this may be one of the mechanisms by which thiram causes TD in broilers.

High-performance liquid chromatography analysis of rubber allergens in protective gloves used in health care

A high-performance liquid chromatography (HPLC) method developed for analysis of zinc dithiocarbamates was validated and used to perform a survey of disposable medical gloves used in southern Sweden. The gloves were extracted with acetone at room temperature for 10 min by shaking. The extracts were injected into a polyether ether ketone lined HPLC column, and peaks were analysed by a diode-array detector. The survey shows that of 19 gloves analysed, 10 contained zinc diethyldithiocarbamate (0.070-3.5 mg/g), 3 contained zinc pentamethylenedithiocarbamate (1.0-4.3 mg/g), 4 contained zinc dibutyldithiocarbamate (0.9-1.1 mg/g), and 2 contained 2-mercaptobenzothiazole (0.005-0.008 mg/g). None of them contained thiurams.

Dissolution of materials in artificial skin surface film liquids

The dissolution of chemical constituents from jewelry, textiles, cosmetics, drugs, industrial chemicals, and particles in direct and prolonged contact with human skin is often assessed in vitro using artificial skin surface film liquids (SSFL). To provide meaningful results, the composition of artificial SSFL should accurately mimic human sweat and sebum, and the conditions of the in vitro test system should accurately reflect in vivo skin conditions. We summarized the reported composition of human SSFL and compared it to 45 different formulations of artificial sweat and 18 formulations of artificial sebum (studies published from 1940 to 2005). Conditions of in vitro dissolution test systems were reviewed and compared to in vivo skin conditions. The concentrations of individual constituents and pH of artificial sweat and concentrations of artificial sebum constituents are not always within ranges reported for human SSFL. Nearly all artificial SSFL lack many of the constituents in human SSFL. To develop a comprehensive model SSFL, we propose a standard SSFL, modified from the two best published sweat and sebum formulations. Little is known concerning the influence of test system conditions on dissolution, including SSFL temperature, container material composition, agitation, and physicochemical properties of the test article on dissolution. Thus, both a need and an opportunity exist for standardizing the composition of artificial SSFL and in vitro dissolution test methodologies. To standardize in vitro dissolution test systems, we recommend: maintaining artificial SSFL at a biologically relevant temperature appropriate to the human activity being modeled, carefully selecting test and sample storage containers to avoid bias in dissolution measurements, accounting for friction between a test article and skin in a biologically plausible manner, and physicochemical characterization of the test article or material to better understand mechanisms of dissolution and potential mechanisms of toxic action of dissolved material. More accurate modeling and better understanding of chemical dissolution from articles in contact with the skin will ultimately improve risk decision making, thereby protecting even the most susceptible persons from adverse health effects resulting from skin exposure.

Fragrance allergy and hand eczema - a review

Because hand eczema and fragrance allergy are common both among patients and in the general population, simultaneous occurrence by chance must be expected. Fragrances are ubiquitous and a part of many domestic and occupational products intended for hand exposure. The present review is based on a systematic literature research using both a manual and a Medline based search. The search identified 39 studies, including epidemiological patch test studies, general population patch test studies, case studies, and studies of occupational groups. The published data indicate a possible association between fragrance allergy and hand eczema. In future studies, a more detailed exposure assessment is needed, combined with patch test studies among patients with hand eczema tested with relevant fragrance allergens, as well as experimental control exposure studies to specific fragrance allergens on the hands. As exposures to fragrances on the hands are often simultaneous exposures to irritants, this combined exposure approach needs to be considered.

Type IV allergy in the food processing industry: sensitization profiles in bakers, cooks and butchers

Data about the impact of allergic contact dermatitis in food processing occupations are scarce. The objective of this study was to identify the most frequent allergens and sensitization profiles in employees of the food processing industry. The results of patch testing performed in 873 bakers, cooks and butchers suspected of having occupational allergic contact dermatitis from 33 dermatological departments of the Information Network of Departments of Dermatology (IVDK) from 1992 to 1999 were analysed. A final diagnosis of allergic contact dermatitis was made in 213 patients (24.4%). Qualitative and quantitative differences in allergen profiles could be identified. Significantly higher sensitization rates were found in employees in the food processing industry, compared to the total test population, for nickel sulphate (22.4% versus 17.2%, p < 0.0005), thiuram mix (4.9% versus 2.6%, p < 0.0005), formaldehyde (3.5% versus 2.1%, p < 0.005) and Compositae mix (6.2%, p < 0.0005). Significantly lower sensitization rates were found for thimerosal (4.5% versus 6.9%, p < 0.05). For patch testing in food workers, we recommend the standard, the rubber and the Compositae series, as well as patients' own products according to the individual history.

Allergenicity of natural rubber latex gloves

The concentrations of proteins, allergens and rubber chemicals are essential parameters of the allergenicity of NRL gloves. To date, a standardized method has been given only for analysis of the protein concentration (DIN EN 455-3), and not for the concentrations of allergens and rubber chemicals. In the present study, we investigated 11 brands of surgical gloves currently available on the German market. Additionally 1 glove, not subjected to final leaching procedures, was added for comparison purposes. Protein concentrations were analysed by different methods in different laboratories. Allergen concentrations were assayed by prick tests in NRL-allergic volunteers and by RAST inhibition methods. Rubber chemicals were analysed by HPTLC and GC. The protein concentrations analysed by the Lowry method in the 2 laboratories gave concordant results, but the correlations between protein and allergen concentrations were low. The protein concentration analysed by HPLC correlated with the allergen concentration, and gave better information on the allergenicity of the gloves. The development of standardized methods for allergen analysis in the assessment routine is necessary, due to significant discrepancy between protein and allergen levels of some gloves. Thiurams were not found in any of the gloves, though carbamates were present in all gloves tested. Our data indicate that washing procedures have little or no effect on the concentration of rubber chemicals.

Contact allergy and exposure patterns to thiurams and carbamates in consecutive patients

Sensitization to rubber is most often due to sensitization to thiurams. Positive patch test reactions to carbamates are less frequent, and usually only diagnosed in patients with positive patch test reactions to thiurams as well. The aim of the present study was to describe the relative frequency of sensitization to thiuram mix (TH mix) and zinc diethyldithiocarbamate (ZDC) in a population where the exposure to these chemicals from rubber gloves was previously studied and considered to be of approximately the same order of magnitude. The thiuram derivatives seemed to be the most important sensitized (frequency 2.8%) compared to ZDC (frequency 0.5%), which has been the most frequently reported sensitizer among the carbamates in rubber gloves. An interesting observation was that the probability that the patient was reacting to ZDC was strongly associated with the strength of the patch test reaction to TH mix. This observation may add a new aspect to the discussion about cross-reactivity versus concomitant sensitization of thiurams and carbamates.

Elicitation thresholds for thiuram mix using petrolatum and ethanol/sweat as vehicles

An estimate of amounts of thiurams that may be released from rubber gloves into synthetic sweat, has previously been generated. These amounts should be compared to elicitation thresholds of patch tests performed with serial dilutions of thiuram mix using synthetic sweat as vehicle. Because of solubility properties of thiurams in aqueous media, such dilutions cannot directly be prepared. In this study, a stem solution was prepared in ethanol. This solution was then further diluted with synthetic sweat. Thiuram mix 0.5 w/v% was the most concentrated solution in ethanol achievable. The patch test reactions were compared to reactions to serial dilutions using petrolatum as vehicle. The experiment revealed that endpoint dilution with synthetic sweat was not achieved in this study. The threshold for elicitation of positive patch test reactions seemed to be lower for ethanol/sweat as vehicle compared to petrolatum: 32% reacted to ethanol/synthetic sweat 0.001 mg/cm2 compared to 14% reacting to thiuram in pet. 0.002 mg/cm2. Based on these results, synthetic sweat may be considered a more relevant medium for threshold finding studies than petrolatum. Because of expected instability of the aqueous solutions, petrolatum is probably a more suitable vehicle for routine testing. The study does not permit final conclusions concerning acceptable thresholds for leachable thiurams in rubber gloves, but it is likely that an acceptable threshold would be substantially less than 0.001 mg/ cm2.