Increasing non-cosmetic exposure and sensitization to isothiazolinones require action for prevention: Review.

Frequent use of methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI in cosmetic products has been the main cause of widespread sensitization and allergic contact dermatitis to these preservatives (biocides). Their use in non-cosmetic products is also an important source of sensitization. Less is known about sensitization rates and use of benzisothiazolinone (BIT), octylisothiazolinone (OIT), and dichlorooctylisothiazolinone (DCOIT), which have never been permitted in cosmetic products in Europe. BIT and OIT have occasionally been routinely patch-tested. These preservatives are often used together in chemical products and articles. In this study, we review the occurrence of contact allergy to MI, BIT, OIT, and DCOIT over time, based on concomitant patch testing in large studies, and case reports. We review EU legislations, and we discuss the role of industry, regulators, and dermatology in prevention of sensitization and protection of health. The frequency of contact allergy to MI, BIT, and OIT has increased. The frequency of contact allergy to DCOIT is not known because it has seldom been patch-tested. Label information on isothiazolinones in chemical products and articles, irrespective of concentration, is required for assessment of relevance, information to patients, and avoidance of exposure and allergic contact dermatitis.

Nine years of patch testing with isocyanates in a clinic of occupational dermatology.

BACKGROUND: Isocyanates are used as starting materials of polyurethane (PU) products. They are relatively important occupational skin sensitizers. OBJECTIVES: To analyse results of a large isocyanate patch test series of 19 isocyanate test substances and 4,4'-diaminodiphenylmethane (MDA), a marker of 4,4'-diphenylmethane diisocyanate (MDI) hypersensitivity. METHODS: Test files were screened for positive reactions in the isocyanate series. Patients with positive reactions were analysed for occupation, exposure and diagnosis. RESULTS: In 2010-2019, 53 patients had positive reactions in the series (16% of 338 patients tested). MDA, the well-established screening substance for MDI allergy, was positive in 30 patients, an in-house monomeric MDI test substance in 23 patients and 3 different polymeric MDI test substances in 19-21 patients. We diagnosed 16 cases of occupational allergic contact dermatitis (OACD) from MDI including 3 pipe reliners. Hexamethylene-1,6-diisocyanate (HDI) oligomers in paint hardeners caused 5 cases of OACD, more cases than 2,4-toluene diisocyanate (TDI; n = 3) and isophorone diisocyanate (IPDI; n = 1) put together. CONCLUSIONS: In contrast to previous studies, polymeric MDI test substances were not superior to a monomeric MDI. Pipe reliners may get sensitised not only by epoxy products and acrylates but also by MDI in hardeners of PU pipe coatings. HDI oligomers were the second most important causes of OACD after MDI.

Effect of the Addition of Graphene Flakes on the Physical and Biological Properties of Composite Paints.

In this study, graphene flakes were obtained using an electrolytic method and characterized using X-ray diffraction (XRD), Raman and FTIR spectroscopy, scanning and transmission electron microscopy (SEM/TEM). Graphene-based composites with varying concentrations of 0.5%, 1% and 3% by weight were prepared with acrylic paint, enamel and varnish matrices. The mechanical properties were evaluated using micro-hardness testing, while wettability and antimicrobial activity against three pathogens (Staphylococcus aureus 33591, Pseudomonas aeruginosa 15442, Candida albicans 10231) were also examined. The results indicate that the addition of graphene flakes significantly enhances both the mechanical and antimicrobial properties of the coatings.

Virtual Screening of a Library of Naturally Occurring Anthraquinones for Potential Anti-Fouling Agents.

Marine biofouling is the undesired accumulation of organic molecules, microorganisms, macroalgae, marine invertebrates, and their by-products on submerged surfaces. It is a serious challenge for marine vessels and the oil, gas, and renewable energy industries, as biofouling can cause economic losses for these industries. Natural products have been an abundant source of therapeutics since the start of civilisation. Their use as novel anti-fouling agents is a promising approach for replacing currently used, harmful anti-fouling agents. Anthraquinones (AQs) have been used for centuries in the food, pharmaceutical, cosmetics, and paint industries. Citreorosein and emodin are typical additives used in the anti-fouling paint industry to help improve the global problem of biofouling. This study is based on our previous study, in which we presented the promising activity of structurally related anthraquinone compounds against biofilm-forming marine bacteria. To help uncover the anti-fouling potential of other AQ-related structures, 2194 compounds from the COCONUT natural products database were analysed. Molecular docking analysis was performed to assess the binding strength of these compounds to the LuxP protein in Vibrio carchariae. The LuxP protein is a vital binding protein responsible for the movements of autoinducers within the quorum sensing system; hence, interrupting the process at an early stage could be an effective strategy. Seventy-six AQ structures were found to be highly docked, and eight of these structures were used in structure-based pharmacophore modelling, resulting in six unique pharmacophore features.

Liquid chromatography and mass spectrometry for the analysis of acylglycerols in art and archeology.

Lipid characterization in art and archeology, together with the study of lipid degradation processes, is an important research area in heritage science. Lipid-based materials have been used as food since ancient times, but also employed as illuminants and as ingredients in cosmetic, ritual, and pharmaceutical preparations. Both animal and plant lipids have also been processed to produce materials used in art and crafts, such as paint binders, varnishes, waterproofing agents, and coatings. Identifying the origin of the lipid materials is challenging when they are found in association with artistic historical objects. This is due to the inherent complex composition of lipids, their widespread occurrence, and the chemical alterations induced by ageing. The most common approach for lipid characterization in heritage objects entails profiling fatty acids by gas chromatography/mass spectrometry after saponification or transesterification. New developments in high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) for the characterization of acylglycerols, together with more efficient sample treatments, have fostered the introduction of liquid chromatography for characterizing the lipid profile in heritage objects. This review reports the latest developments and applications of HPLC-MS for the characterization of lipid materials in the field of heritage science. We describe the various approaches for sample pretreatment and highlight the advantages and limitations of HPLC-MS in the analysis of paint and archeological samples. © 2020 John Wiley & Sons Ltd.

Effects of currently used marine antifouling paint biocides on green fluorescent proteins in Anemonia viridis.

Some of the antifouling booster biocides affects the marine ecosystem negatively. The booster biocides that are resistant to degradation are accumulated in the sediment of the oceans. One of the sedentary organisms in the Mediterranean Sea is Anemonia viridis. This study aims at showing the toxicities of common biocides such as irgarol, seanine-211, zinc omadine, and acticide on the fluorescence by GFPs of A. viridis. The decreases in the fluorescence intensities of the GFP were measured within different booster biocide concentrations. The results show that fluorescent intensities of GFP proteins decrease more than 50% when they are exposed to different concentrations of irgarol, zinc omadine, acticide. In conclusion, ecosystem health should be prioritized when new antifouling paint compositions are proposed. From the results, it seems that A. viridis can be considered as a vulnerable organism and it is sensitive to booster biocides within self-polishing antifouling paint formulations.

Targeted proteomics for the analysis of cultural heritage: application of broadband collision-induced dissociation mass spectrometry.

A broadband collision-induced dissociation (bbCID) fragmentation mode was proposed for liquid chromatography-mass spectrometric targeted analysis of tryptic peptides obtained from proteins in samples of decoration paint coating. In this approach, a mass spectrometric dataset contains the information on the parent and all fragment ions. This maintains a balance between the quantity of simultaneously acquired data and the sensitivity of the method, which is beneficial under coupling with analytical chromatography. In this study, characteristic peptides were selected for casein, ovalbumin, and collagen, which are the most commonly used binder proteins in the artworks. A simplified sample preparation protocol including only protein extraction and trypsinization was tested and successfully implemented. The combination of analytical chromatography with bbCID MS technique is a lower cost alternative to the use of high-end nano-LC-MS approaches in the investigation of cultural heritage objects of regional or local importance, e.g., prior to and/or during restoration works. It was demonstrated that, for the paint coating samples, the required level of sensitivity could be acquired through the data-independent MS/MS strategy. The proposed approach was tested on a sample obtained during the restoration work at the Gromov cottage in the Lopukhin Garden (middle of the XIX century). As a result, the main protein component, collagen, was identified using 6 characteristic peptides, which may indicate the use of gelatin-based glue. For instance, the identification of the peptide GVQGPPoxGPAGPR of the incoming collagen composition α-1 was undertaken by three parameters: m/z of the precursor ion of 553.2910, m/z of the fragment ion y9 of 821.4238, and retention time of 1.9 min.

Disentangling biological effects of primary nanoplastics from dispersion paints' additional compounds.

Microplastic particles (MP) and nanoplastic particles (NP) as persistent anthropogenic pollutants may impact environmental and human health. A relevant potential source of primary MP and NP is water-based dispersion paint which are commonly used in any household. Given the worldwide high application volume of dispersion paint and their diverse material composition MP and NP may enter the environment with unforeseeable consequences. In order to understand the relevance of these MP and NP from paint dispersion we investigated the components of two representative wall paints and analyzed their composition in detail. The different paint components were then investigated for their impact on the model organism Daphnia magna and on a murine cell line. Plastic NP, dissolved polymers, titanium dioxide NPs, and calcium carbonate MPs demonstrated adverse effects in both biological test systems, indicating detrimental consequences of several typical components of wall paints upon release into the environment. The outcome of this study may form the basis for the evaluation of impact on other organisms, environmental transport and impact, other related technical materials and for the development of strategies for the prevention of potential detrimental effects on organisms.

Concise Historic Overview of Strain Sensors Used in the Monitoring of Civil Structures: The First One Hundred Years.

Strain is one of the most frequently monitored parameters in civil structural health monitoring (SHM) applications, and strain-based approaches were among the first to be explored and applied in SHM. There are multiple reasons why strain plays such an important role in SHM: strain is directly related to stress and deflection, which reflect structural performance, safety, and serviceability. Strain field anomalies are frequently indicators of unusual structural behaviors (e.g., damage or deterioration). Hence, the earliest concepts of strain sensing were explored in the mid-XIX century, the first effective strain sensor appeared in 1919, and the first onsite applications followed in the 1920's. Today, one hundred years after the first developments, two generations of strain sensors, based on electrical and fiber-optic principles, firmly reached market maturity and established themselves as reliable tools applied in strain-based SHM. Along with sensor developments, the application methods evolved: the first generation of discrete sensors featured a short gauge length and provided a basis for local material monitoring; the second generation greatly extended the applicability and effectiveness of strain-based SHM by providing long gauge and one-dimensional (1D) distributed sensing, thus enabling global structural and integrity monitoring. Current research focuses on a third generation of strain sensors for two-dimensional (2D) distributed and quasi-distributed sensing, based on new advanced technologies. On the occasion of strain sensing centenary, and as an homage to all researchers, practitioners, and educators who contributed to strain-based SHM, this paper presents an overview of the first one hundred years of strain sensing technological progress, with the objective to identify relevant transformative milestones and indicate possible future research directions.

Connecting Rheological Properties and Molecular Dynamics of Egg-Tempera Paints based on Egg Yolk.

Egg-tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico-chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg-tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1 H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment.

Diversity of experimental designs for the fabrication of antifungal surfaces for the built environment.

The fungal infestation in construction industries is a major problem with a very high removal cost that needs to be controlled not only to prevent the fouling of surfaces but also to prevent allergic reactions or respiratory problems especially in immunocompromised individuals. To combat fungal invasion, several experimental approaches to produce antifungal surfaces have been developed. Here, we reviewed the current strategies in designing antifungal surfaces and classified those approaches into two major categories: the chemical and/or physical modification of the actual material surface and nanoparticle-based coating formulations created using the functionalised nanoparticles. KEY POINTS: • Antifungal effect of micro- and nano-structured superhydrophobic surfaces. • Long-term antifungal effect conferred through biocides. • Advanced coatings based on functionalised silica, TiO2 and ZnO nanoparticles.

The effects of paints and moisture content on the indoor air emissions from pinewood (Pinus sylvestris) boards.

The emissions of volatile organic compounds (VOCs) from building materials may significantly contribute to indoor air pollution, and VOCs have been associated with odor annoyance and adverse health effects. Wood materials together with coatings are commonly used indoors for furniture and large surfaces such as walls, floors, and ceilings. This leads to high surface-to-volume ratios, and therefore, these materials may participate remarkably to the VOC levels of indoor environment. We studied emissions of VOCs and carbonyl compounds from pinewood (Pinus sylvestris) boards of 10% and 16% moisture contents (MC) with three paints using small-scale test chambers (27 L). The emissions from uncoated pinewood and paints (on a glass substrate) were tested as references. The 28-day experiment showed that the VOC emissions from uncoated pinewood were lower from sample with 16% MC. Painted pinewood samples showed lower emissions compared to paints on glass substrate. Additionally, paints on 16% MC pinewood exhibited lower emissions than on drier 10% MC wood. The emissions from painted pinewood samples were dominated by paint-based compounds, but the share of wood-based compounds increased over time. However, we noticed differences between the paints, and wood-based emissions were clearly higher with the most permeable paint.

Evolution of methylisothiazolinone sensitization: A Belgian multicentric study from 2014 to 2019.

BACKGROUND: In the 2010s an epidemic of allergic contact dermatitis to methylisothiazolinone (MI) occurred in Europe. European authorities banned the use of methylisothiazolinone in leave-on cosmetics in 2017 and limited its use in rinse-off products in 2018. OBJECTIVES: To investigate the sensitization rate to MI in Belgium between January 2014 and December 2019, and to assess cosensitizations to octylisothiazolinone (OIT) and benzisothiazolinone (BIT) in MI-sensitized patients. METHODS: A retrospective study of patch test results with MI, OIT, and BIT observed in patients attending five Belgian hospitals. RESULTS: Overall, 560 of 10 029 patients (5.58%) had a positive patch test reaction to MI, and its sensitization rate decreased from 7.9% in 2014 to 3.1% in 2019. Rinse-off cosmetics, paints, and detergents were the most prevalent sensitization sources in recent years. Simultaneous reactions readily occurred to OIT, and, surprisingly, and increasingly, also to BIT. CONCLUSIONS: Contact allergy to MI in Belgium has reached a pre-epidemic level, reflecting the impact of recent regulatory measures. Leave-on cosmetics, in contrast to rinse-off products, have almost disappeared as sensitization sources in Europe. Paints and detergents also remain problematic. The remarkably high number of patients (co)sensitized to BIT should be a focus of future research.

Environmental risk assessment of using antifouling paints on pleasure crafts in European Union waters.

To ensure sustainable use of antifouling paints, the European Union have developed a new environmental risk assessment tool, which a product must pass prior to its placement on the market. In this new tool, environmental concentrations are predicted based on estimated release rates of biocides to the aquatic environment and risk characterization ratios are calculated in regional spreadsheets. There are currently two methods in use to predict release rates of biocides; a calculation method and a laboratory method. These methods have been believed to overestimate environmental release of biocides and therefore fixed correction factors to reduce the release rate can be applied. An alternative method, known as the XRF method, has recently been developed and used to derive field release rates from antifouling paints. The aim of this study was to review the new environmental risk assessment tool and assess how the choice of release rate method and application of correction factors impact the approval of antifouling paint products. Eight coatings were environmentally risk assessed for usage in four European marine regions; Baltic, Baltic Transition, Atlantic and Mediterranean; by applying release rates of copper and zinc determined with the different methods. The results showed none of the coatings to pass the environmental risk assessment in the Baltic, Baltic Transition and the Mediterranean if field release rates were used. In contrast, most of the coatings passed if the correction factors were applied on the release rates obtained with the calculation or laboratory method. The results demonstrate the importance of release rate method choice on the outcome of antifouling product approval in EU. To reduce the impact of antifouling paints on the marine environment it is recommended that no correction factors should be allowed in the environmental risk assessment or preferably that site-specific field release rates are used. If the regulation in the European Union (and elsewhere) continues to allow correction factors, the pressure of biocides to the environment from leisure boating will result in degradation of marine ecosystems.

New Insights into the Degradation Path of Deltamethrin.

Pyrethroids are among the insecticidal compounds indicated by the World Health Organization for mitigation of vector-borne diseases. Active deltamethrin (with chiral configuration α-S,1-R-cis) is one of the most effective pyrethroids characterized by low toxicity to humans, and it is currently tested as active ingredient for insecticidal paints. Nevertheless, several degradation processes can occur and affect the insecticidal efficacy in the complex paint matrix. In the present study, a detailed NMR analysis of deltamethrin stability has been carried out under stress conditions, mimicking a water-based insecticidal paint environment. Two novel by-products, having a diastereomeric relationship, were identified and their structure was elucidated by combining NMR, HPLC, GC-MS, and ESI-MS analyses. These compounds are the result from a nucleophilic addition involving deltamethrin and one of its major degradation products, 3-phenoxybenzaldehyde. Given the known toxicity of the aldehyde, this reaction could represent a way to reduce its concentration into the matrix. On the other hand, the toxicology of these compounds towards humans should be addressed, as their presence may adversely affect the performance of deltamethrin-containing products.

Heavy Metals in Acrylic Color Paints Intended for the School Children Use: A Potential Threat to the Children of Early Age.

Heavy metals are the harmful elements, regarded as carcinogens. Nevertheless, owing to their physical and chemical properties, they are still used in the production of several commercial products. Utilization of such products increases the chance for the exposure of heavy metals, some of them are categorized as probable human carcinogens (Group 1) by the International Agency for Research on Cancer. Exposure of heavy metals to school children at early age can result severe life time health issues and high chance of emerging cancer. Thus, we have performed study relating to the presence of heavy metals in acrylic color paints commonly used by the school children. Acrylic paints of different colors were assayed for seven potential heavy metals manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) using microwave digestion and iCAPQ inductively coupled plasma mass spectrometry (ICP-MS) system. The optimized method including paints digestion reagents nitric acid (HNO3, 65%, 5 mL) and hydrofluoric acid (HF, 40%, 2 mL) have offered excellent method performance with recovery values ranged between 99.33% and 105.67%. The elements were identified in all of the analyzed samples with concentrations ranged from 0.05 to 372.59 µg/g. Cd constitutes the lower percentage (0.05%), whereas Zn constitutes high ratio contribution which was tremendously high (68.33%). Besides, the paints contamination was also color specific, with considerably total heavy metal concentrations found in brunt umber (526.57 µg/g) while scarlet color (12.62 µg/g) contained lower amounts. The outcomes of our investigation highlight the necessity for guidelines addressing the heavy metals in acrylic color paints intended for the school children usage.

An Exemplary Gay Scientist and Mentor: Martin Gouterman (1931-2020).

Martin Gouterman (1931-2020) was one of the foundational figures of modern porphyrin science. After completing his Ph.D. at The University of Chicago in 1958, he joined Harvard, where he developed his eponymous four-orbital model. In 1966, he moved to the University of Washington Seattle (UW). Here he came out as gay and helped set up Seattle's first gay rights group, the Dorian Society. At UW, Gouterman accomplished an "optical taxonomy" of the major classes of porphyrin derivatives and pioneered pressure-sensitive paints based on phosphorescent platinum porphyrins to map the partial pressure of oxygen on airplane wings. Revered by his students and co-workers for his brilliant yet gentle advising, Gouterman remains a beacon for a more humane and inclusive scientific enterprise.

Photoaggravated allergic contact dermatitis and transient photosensitivity caused by methylisothiazolinone.

BACKGROUND: Photoaggravated allergic contact dermatitis caused by methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) and MI has been reported. OBJECTIVES: To describe the clinical characteristics and results of (photo)patch tests and photo-tests of 10 patients in Belgium and France suffering from photoaggravated contact dermatitis caused by MI. PATIENTS AND METHODS: Five men and five women, with a median age of 49.5 years, were investigated between January 2012 and February 2017 because of suspected photoaggravated contact dermatitis. Patch tests, photopatch tests and/or photo-tests were performed. RESULTS: Seven patients had positive patch test reactions to both MCI/MI and MI, whereas 3 patients had positive patch test reactions only to MI. In most cases, MI was the (strong) primary sensitizer. Photopatch tests with MCI/MI and/or MI gave stronger reactions than patch tests with these derivatives, indicating photoaggravation. Sensitization probably took place from cosmetics and work-related biocides, whereas elicitation of dermatitis was remarkably often related to airborne exposure to MI present in paints or industrial biocides. Four patients suffered from transient photosensitivity. CONCLUSION: Photoaggravated allergic contact dermatitis and transient photosensitivity caused by MI is a peculiar clinical presentation of allergic contact dermatitis caused by this preservative, and should be considered in daily clinical practice.

Single-Particle Ratiometric Pressure Sensing Based on "Double-Sensor" Colloidal Nanocrystals.

Ratiometric pressure sensitive paints (r-PSPs) are all-optical probes for monitoring oxygen flows in the vicinity of complex or miniaturized surfaces. They typically consist of a porous binder embedding mixtures of a reference and a sensor chromophore exhibiting oxygen-insensitive and oxygen-responsive luminescence, respectively. Here, we demonstrate the first example of an r-PSP based on a single two-color emitter that removes limitations of r-PSPs based on chromophore mixtures such as different temperature dependencies of the two chromophores, cross-readout between the reference and sensor signals and phase segregation. In our approach, we utilize a novel "double-sensor" r-PSP that features two spectrally separated emission bands with opposite responses to the O2 pressure, which boosts the sensitivity with respect to traditional reference-sensor pairs. Specifically, we use two-color-emitting dot-in-bulk CdSe/CdS core/shell nanocrystals, exhibiting red and green emission bands from their core and shell states, whose intensities are respectively enhanced and quenched in response to the increased oxygen partial pressure that effectively tunes the position of the nanocrystal's Fermi energy. This leads to a strong and reversible ratiometric response at the single particle level and an over 100% enhancement in the pressure sensitivity. Our proof-of-concept r-PSPs further exhibit suppressed cross-readout thanks to zero spectral overlap between the core and shell luminescence bands and a temperature-independent ratiometric response between 0 and 70 °C.

Pigment and Binder Concentrations in Modern Paint Samples Determined by IR and Raman Spectroscopy.

Knowledge of the techniques employed by artists, such as the composition of the paints, colour palette, and painting style, is of crucial importance not only to attribute works of art to the workshop or artist but also to develop strategies and measures for the conservation and restoration of the art. While much research has been devoted to investigating the composition of an artist's materials from a qualitative point of view, little effort has been made in terms of quantitative analyses. This study aims to quantify the relative concentrations of binders (acrylic and alkyd) and inorganic pigments in different paint samples by IR and Raman spectroscopies. To perform this quantitative evaluation, reference samples of known concentrations were prepared to obtain calibration plots. In a further step, the quantification method was verified by additional test samples and commercially available paint tubes. The results obtained confirm that the quantitative method developed for IR and Raman spectroscopy is able to efficiently determine different pigment and binder concentrations of paint samples with high accuracy.