Occupational asthma caused by triglycidyl isocyanurate

Characterization of Airborne Particulates and Worker Exposures in Electro-static Powder Coating Operations

This study was to examine the airborne particulates/dusts and worker exposures in electro-static powder coating operations. Temporal variation and size distribution of dusts were assessed using direct-reading instrument, while the worker task-specific dust exposures (n = 41) were measured in three factories using conventional filter method. Additionally, toxic metal levels in the coating powder (n = 27) were analyzed to assess hazard potentials. Continuous monitoring of airborne respirable dust levels indicated large temporal variation across a normal working day. The particulate levels outside spraying booths were generally low (below 0.10 mg m-3) during normal spraying operation, but short-term level may reach as high as 21.8 mg m-3 (averaged at 4-5 mg m-3) when specific task such as cleaning the pipelines and spraying booth, was performed. Exploratory assessment on particle size distribution at four major working zones, administration, uploading, spraying, and baking, indicated no major difference among the zones, and between factories. The particle count median aerodynamic diameter was 0.88-1.69 µm, while the mean number concentrations were 10.97, 15.17, 18.49, and 27.03 (# cm-3) for zones administration, uploading, spraying, and baking, respectively. The worker task-specific dust exposures were found low during normal spraying, with the mean short-term total and respirable dust concentrations being 0.88 and 0.41 mg m-3, respectively. Both levels increased to 3.48 and 5.19 mg m-3, respectively (P < 0.05), if powder changing and system cleaning were done. Short-term total and respirable dust concentrations were 94.2 and 56.1 mg m-3, respectively, when complete cleaning process was performed inside spraying booth. Both levels exceeded the short-term exposure limits. The mean concentration of metals in the powder samples were 6.78, 9.52, 10 717, 2805, 1020, and 1361 µg g-1 for Pb, Cr (total), Al, Fe, Cu, and Sr, respectively. This study demonstrated that cleaning of spraying booth resulted in high dust exposures well exceeding the exposure limit. Toxic metals, particularly Pb, Cd, and Cr (total), levels measured in the powder samples were found low, and the resulting exposures were below the exposure limits, indicating relative low risks associated with the exposure at current dust levels.

Occupational Asthma From Epoxy Compounds

BACKGROUND

Two-component epoxy resin systems (ERSs) composed of epoxy resin and polyamine hardeners are extensively used in industrial and construction coating. Triglycidyl isocyanurate (TGIC) is another type of epoxy derivative, mostly encountered in polyester powder paints. Epoxy compounds are well-known skin sensitizers, but their respiratory-sensitizing potential is largely unknown.

OBJECTIVE

To report patients examined for occupational asthma (OA) from epoxy compounds.

METHODS

We retrospectively reviewed patient files of cases tested with a placebo-controlled specific inhalation challenge (SIC) according to their workplace exposure-either by mixing epoxy resin and the polyamine hardener of a 2-component paint or by dusting or heating TGIC-containing powder paint. The data were collected from the Finnish Institute of Occupational Health, Helsinki, Finland, and at Fundación Jiménez Díaz Hospital, Madrid, Spain, during 1997 to 2018. We also measured airborne polyamine and solvent vapors at the workplace and during SIC with ERSs.

RESULTS

Altogether 113 patients with work-related asthma symptoms underwent SIC with ERSs. Fifteen cases (13%) had positive SIC reactions confirming OA; in 12 cases reactions were late-type, in 1 case early, and in 2 cases combined. The median duration of exposure for patients with OA was 10 years; 2 of them (13%) had a diagnosis of allergic contact dermatitis from ERS compounds. In addition, 3 cases had a positive SIC reaction to TGIC. The airborne polyamine levels measured were low.

CONCLUSION

ERSs and TGIC can cause sensitizer-induced OA in some exposed workers. Respiratory exposure to ERSs is difficult to demonstrate using air measurements.

Determination of triglycidyl isocyanurate from air samples by ultra-performance liquid chromatography coupled with coordination ion spray mass spectrometry

RATIONALE

Ultra-performance liquid chromatography (UPLC) coupled with coordination ion spray tandem mass spectrometry was used for the analysis of air samples containing triglycidyl isocyanurate. The method is not affected by any chromatographic interference and the filter extract is compatible with the UPLC system, as opposed to approaches using high-performance liquid chromatography coupled with ultraviolet detection and gas chromatography coupled with mass spectrometry.

METHODS

Accu-cap™ filters that had sampled triglycidyl isocyanurate were extracted using a mixture of acetonitrile/acetone (95/5) diluted with 3 volumes of water and were then analyzed. The mass spectrometry method uses sodium as the alkali adduct complexing with the triglycidyl isocyanurate in positive mode, and this complex is then analyzed using the survivor mode where the same ion is monitored in the first and third quadrupoles of a triple quadrupole mass spectrometer.

RESULTS

The method has a limit of detection and limit of quantitation of 50 and 170 ng/filter, respectively. The dynamic range was between 480 and 24,000 ng/sample, which is equivalent to 2 µg/m(3) and 100 µg/m(3) based on a sampling volume of 240 L. The intra- and inter-day precisions were both <4% and the overall accuracy was 97 ± 3%. The method was tested with personal breathing zone random samples collected from workers using triglycidyl isocyanurate in their tasks, and all the random samples were easily quantified.

CONCLUSIONS

A new method by UPLC coupled with coordination ion spray tandem mass spectrometry using sodium as the alkali adduct is now available for industrial hygienists who want to evaluate exposures of workers to triglycidyl isocyanurate in workplaces.

Contribution of exhaled nitric oxide measurement in airway inflammation assessment in asthma. A position paper from the French Speaking Respiratory Society

Nitric oxide (NO) is both a gas and a ubiquitous inter- and intracellular messenger with numerous physiological functions. As its synthesis is markedly increased during inflammatory processes, NO can be used as a surrogate marker of acute and/or chronic inflammation. It is possible to quantify fractional concentration of NO in exhaled breath (FENO) to detect airway inflammation, and thus improve the diagnosis of asthma by better characterizing asthmatic patients with eosinophilic bronchial inflammation, and eventually improve the management of targeted asthmatic patients. FENO measurement can therefore be viewed as a new, reproducible and easy to perform pulmonary function test. Measuring FENO is the only non-invasive pulmonary function test allowing (1) detecting, (2) quantifying and (3) monitoring changes in inflammatory processes during the course of various respiratory disorders, including corticosensitive asthma.

New occupational and environmental causes of asthma and extrinsic allergic alveolitis

Asthma and extrinsic allergic alveolitis (EAA) remain prevalent respiratory diseases and the cause of a significant disease burden. This article reviews the recent occupational and environmental causes described for these conditions. Even over the limited time spam addressed by this article, novel agents and new data relating to already suggested causes have been described. Various types of work tasks or exposures are described that appear to cause both asthma and EAA. Isocyanates, the best example of dual potential to cause asthma and EAA are discussed, as is the new understanding of the role metal-working fluids play when causing respiratory diseases.

Old and new causes of occupational asthma

International reviews suggest that the median proportion of adult cases of asthma attributable to occupational exposure is between 10% and 15%. Therefore, it is essential that clinicians have a broad knowledge of the various causes associated with occupational asthma. Occupational asthmagens are categorized as low-molecular-weight (LMW, ≤1000 kd) and high-molecular-weight (HMW, ≥1000 kd) antigens. The purpose of this article is to review the most common representative LMW and HMW causes of occupational asthma over the past 70 years, with specific emphasis on newer causes reported over the past 5 years.