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This systematic review, conducted according to the PRISMA guidelines, focuses on genotoxicity of oxidative hair dye precursors. The search for original papers published from 2000 to 2021 was performed in Medline, Web of Science, Cochrane registry, Scientific Committee on Consumer Safety of the European Commission and German MAK Commission opinions. Nine publications on genotoxicity of p-phenylenediamine (PPD) and toluene-2,5-diamine ( p-toluylenediamine; PTD) were included, reporting results of 17 assays covering main genotoxicity endpoints. PPD and PTD were positive in bacterial mutation in vitro assay, and PPD tested positive also for somatic cell mutations in the Rodent Pig-a assay in vivo. Clastogenicity of PPD and PTD was revealed by in vitro chromosomal aberration assay. The alkaline comet assay in vitro showed DNA damage after PPD exposure, which was not confirmed in vivo , where PTD exhibited positive results. PPD induced micronucleus formation in vitro, and increased micronucleus frequencies in mice erythrocytes following high dose oral exposure in vivo. Based on the results of a limited number of data from the classical genotoxicity assay battery, this systematic review indicates genotoxic potential of hair dye precursors PPD and PTD, which may present an important health concern for consumers and in particular for professional hairdressers.

Background. Hemoglobin is a hemoprotein which in the presence of oxidative equivalents, such as H2O2, can act as peroxidase with a very high oxidative potential. Hemoglobin oxidation is accompanied by generation of highly oxidized forms of iron and globin radicals that have high oxidative activity and are toxic to cells. In addition, peroxidase activity may indicate structural changes that occur in the hemoglobin molecule as a result of chemical modification. Materials and Methods. Erythrocyte suspension was subjected to vibration for 3 h within the frequency range from 8 to 32 Hz with amplitudes of 0.5 ± 0.04 and 0.9 ± 0.08 mm. At certain intervals, hemoglobin peroxidase activity was determined together with the content of its ligand forms in the hemolysates of cells. Additionally, experiments were performed to investigate the mechanism and calculate the kinetic parameters of peroxidase reaction. Results and Discussion. Experimental data on low-frequency vibrations effect on erythrocyte hemoglobin peroxidase activity were analyzed. The kinetics of the oxidation reaction of p-phenylenediamine by hemoglobin in erythrocytes was studied. It was found that peroxidase oxidation has a ping-pong mechanism. The kinetic parameters of the peroxidase reaction involving hemoglobin were determined. The change of kinetic parameters after two-hour exposure to the incubation medium and low-frequency vibration was studied. A possible mechanism of action of hemoglobin in oxidation reactions involving H2O2 was proposed. Conclusion. Any effect that initiates the formation of methemoglobin leads to an increase in the peroxidase activity of hemoglobin due to the involvement of the latter in the pseudoperoxidase cycle and the formation of toxic reactive globin radicals. The high content of oxyhemoglobin in the cell, observed under vibrations within the frequency range of 16–32 Hz with an amplitude of 0.9 ± 0.08 mm, can prevent its oxidation and involvement in the pseudoperoxidase cycle.

The wide use and continuous abrasion of rubber-related products appears to be leading to an incredible release of p-phenylenediamine (PPD) antioxidants in the environment. However, no related research has been conducted on the pollution characteristics and potential health risks of PM2.5-bound PPDs. We report for the first time the ubiquitous distributions of six emerging PPDs and a quinone derivative, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPDQ), in PM2.5 from urban areas of China. Atmospheric contamination levels of PM2.5-bound PPDs were found to be mostly in pg m-3 amounts between 2018 and 2019. Urban vehicle rubber tire abrasion was found to probably contribute to the PPDs in PM2.5 and accounted for their significant spatiotemporal-dependent concentration variations. Furthermore, 6PPDQ, an emerging oxidation product of 6PPD in the environment, was first quantified (pg m-3) with a total detection rate of 81% in the urban PM2.5, demonstrating its broad existence. On the basis of the determined ambient concentrations, the annual intakes of PPDs and 6PPDQ for adults were not low, indicating their possible human health risks induced by long-term exposure. This study confirms the widespread occurrence of PPDs and 6PPDQ in PM2.5, showing that the pollution of such compounds in urban air should not be underestimated.

A temperature-sensitive hair dye was prepared with a poloxamer-sodium alginate mixture. When the hair dye was applied to the hair (< 32 °C), it retained its flow dynamics. The hair dye was able to undergo a phase change and formed a solid as soon as it touched the scalp (32°C), which reduced the transdermal amount of p-phenylenediamine (PPD) and also adverse effects and toxicity. Compared to a conventional hair dye, the temperature-sensitive hair dye achieved a reduction of the transdermal amount of p-phenylenediamine by almost 65% at different concentrations. At the same time, the colouring effect was not significantly reduced. The poloxamer alginate hydrogel can be used as a novel colouring material to reduce the harm of the dye intermediate to the human body when colouring hair.

Metal-organic frameworks (MOFs) have attracted extensive attention as precursors for the preparation of carbon-based materials due to their highly controllable composition, structure, and pore size distribution. However, there are few reports of MOFs using p-phenylenediamine (pPD) as the organic ligand. In this work, we report the preparation of a bimetallic MOF (CoCu-pPD) with pPD as the organic ligand, and its derived hollow carbon spheres (BMHCS). CoCu-pPD exhibits a hollow spherical structure assembled by nanosheets. BMHCS inherits the unique hollow spherical structure of CoCu-pPD, which also shows a large specific surface area and heteroatom doping. When using as the anode of sodium-ion batteries (SIBs), BMHCS exhibits excellent cycling stability (the capacity of 306 mA h g−1 after 300 cycles at a current density of 1 A g−1 and the capacity retention rate of 90%) and rate capability (the sodium storage capacity of 240 mA h g−1 at 5 A g−1). This work not only provides a strategy for the preparation of pPD-based bimetallic-MOFs, but also enhances the thermal stability of the pPD-based MOFs. In addition, this work also offers a new case for the morphology control of assembled carbon materials and has achieved excellent performance in the field of SIBs.

The substituted p-phenylenediamines (PPDs) represent a suite of effective antioxidants broadly applied in rubber industries. However, knowledge of their environmental occurrences and fate remains e...

Organic aromatic amines are widely used in various fields such as pharmaceuticals, pesticides, dyes, and tobacco smoke. The pollution of organic amines has become a problem that cannot be ignored, due to the extensive harmful effects on the environment and public health, which has become one of the most concerned frontier fields in the world. Identifying and microdetecting o-phenylenediamine (OPD), m-phenylenediamine (MPD), and p-phenylenediamine (PPD) using MOFs have rarely been reported. On the basis of the blue emission properties of Cu-TBDA constructed with 5,5'-((6-chloro-1,3,5-triazine-2,4-diyl)bis(azanediyl))diisophthalic acid (H4TBDA) ligand, Cu-TBDA was studied primarily to identify and detect aromatic diamine family as a multifunctional chemical sensor. Interestingly, Cu-TBDA has a very high selectivity and sensitivity to OPD and MPD with a low limit of detection (5.00 μM for OPD and 1.77 μM for MPD). Especially for OPD, Cu-TBDA has a unique switching function for it. When the concentration of OPD is less than 9.1 × 10-4 M, the fluorescence response of Cu-TBDA suspension exhibit enhanced. However, when the concentration of OPD is more than 9.1 × 10-4 M, the emission intensity displays quenching phenomenon. Therefore, Cu-TBDA as a chemical sensor not only has recognition and detection functions for organic aromatic amines but also first exhibits turn-on and -off sensing behavior toward OPD.

The dye mixtures formed from three commercial hair colour formers were purified by absorption onto human hair wefts, washed and dried, extracted with dichloromethane:trifluoroacetic acid (75:25) and then analysed by liquid chromatography–mass spectrometry. Only 1–2 dyes were identified from each complex mixture of commercial aromatic amines along with a broad UV absorption mainly consisting of mixtures of quaternary ammonium salts from shampoos and some surfactants. Mecetronium ethyl sulfate and didecyldimethylammonium chloride were the main ammonium salts.

A novel method was developed for the sensitive and visual detection of p-phenylenediamine (PPD) via immobilizing the target specie PPD on dialdehyde cellulose membrane (DCM) followed by the reaction with salicylaldehyde. The obtained solid fluorescent membrane (S-PPD-DCM) emitted yellow fluorescence under 365 nm UV light. DCM was not only used as a solid matrix but also played a vital role in the enrichment of PPD. Experimental variables influencing the fluorescence signal were investigated and optimized. Under the optimum conditions, a detection limit of 5.35 μg L−1 was obtained and two linear ranges were observed at 10–100 and 100–1000 μg L−1, respectively. Moreover, the fluorescence of the resultant membrane can still be visualized by naked eye when PPD concentration was 50 μg L−1. The detection of PPD was hardly affected by the coexistence of 1 mg L−1 of o-phenylenediamine, m-phenylenediamine or p henylamine , exhibiting good selectivity. The developed method involved in a two-step Schiff base reaction and enhanced the fluorescence emission via blocking nonradiative intramolecular rotation decay of the excited molecules. It was applied to determine the PPD in spiked hair dye with satisfactory results.

Background: Hair coloring, or hair coloring, is the follow of fixing the hair color. The most reasons for this area unit cosmetic: to hide gray or white hair, to alter to a color thought to be additional modern or fascinating, or to revive the initial hair color once, it's been stained by hairdressing process or sun bleaching. Hair coloring is often done professionally by a stylist or severally reception. Celtic folks colored their hair blonde; they bleach it by laundry them in lime and brushing it back from their foreheads. The coloring of hair is associate ancient art that involves treatment of the hair with varied chemical compounds. In history, the dyes were obtained from plants. The event of artificial dyes for hair is derived from the legendary discovery of the reactivity of para-phenylenediamine (PPD) with air. Results: Hair dyes are cosmetic compounds that make contact with the skin throughout application. As a result of this skin contact, there exists some health risk related to use of hair dyes. People allergic to protein as an example, can have to be compelled to take care once buying hair color since bound dye includes protein. Protein doesn't have to be compelled to be eaten for it to cause associate hypersensitivity reaction. Skin contact with protein might cause a reaction; thus, resulting in associate hypersensitivity reaction. Symptoms of those reactions will embody redness, sores, itching, burning sensation, and discomfort. Symptoms can typically not be apparent instantly following the appliance and process of the tint, however may arise once hours or maybe daily later. Conclusion: Pigments of the hair got colored by the tactic of removing, replacing, or covering up. Employment of those chemicals may cause varied adverse effects, at the facet of temporary skin irritation and hypersensitivity, hair breakage, skin discoloration, and explosive hair color results. The ultimate color of every strand of hair can depend upon its original color and body. As a result of hair's color and body across the pinnacle and on the length of a hair strand, there'll be delicate variations in shade across the complete head. This provides an additional natural-looking result than the solid, everywhere color of a permanent color. Thus, hair dyes area unit regulated within the industrial marketplace and, as new toxicity knowledge is generated for a few hair dye, and health risks area unit discovered, in a controlled people, employment of hair coloring may end up in aversions and/or skin irritation.

Discovering efficient antibacterial materials is crucial in the area of increasing drug resistance. Herein, we synthesized carbon dots (C-dots) with superior antibacterial activity through a simple one-step hydrothermal method. In this method

BACKGROUND Oxidative hair dyes are an important source of chemical exposure and a major risk factor for the development of occupational and non-occupational allergic contact dermatitis (ACD) worldwide. OBJECTIVE To identify the frequency of common allergens associated with occupational and non-occupational ACD to hair dyes during the last 10 years, in Greece. METHODS We retrospectively reviewed the medical records of patients with suspected ACD to hair dyes from 2010-2019. All patients with patch-test-confirmed ACD to hair dyes were evaluated. RESULTS Out of 501 patients with suspected ACD to hair dyes, 362 had at least one positive reaction to hair dye allergens (62.4% were customers and 37.6% were hairdressers). The mean age of customers and hairdressers was 43.8 years and 30.8 years, respectively. Of the customers, 58.9% were exposed to dyes for >10 years and 61% of hairdressers for

Eggshell is a bio-friendly substance containing by weight of 95% CaCO3 and 5% the oxides (Mn, Si, Al, Fe, Cr, Cu and Ca) and organic substances. The oxidation was used to prepare the poly(p-phenylenediamine) in the presence of potassium persulphate as an oxidant. Poly (p-phenylenediamine) and their nanocomposites with nano eggshell (ESN), carbon nanotube (CNT), and nano eggshell/carbon nanotube were prepared and compared with ground eggshell (ESG). All prepared samples were confirmed via Fourier transforms infrared spectroscopy in addition to Raman spectra. The morphology has been studied by transmission electron microscopy. The thermal stability of the synthesized polymer nanocomposites was evaluated via thermogravimetric analyzer, the results proved that the addition of ESN and ESG to CNT gives better thermal stability than each compound. The addition of (2 wt%) 0.04 gm ESN + CNTs improved the thermal stability of polymer than (1 wt%) 0.02 gm ESN + CNTs. The electrical conductivity properties were studied, the results showed efficiency in the improvement of electrical properties σ = 10−5 ohm−1.cm−1, which form a better composite with higher conductivity, so it can be used as a semiconductor.

Objectives To analyze trends in the prevalence of contact sensitization to p-phenylenediamine between 2004 and 2014, taking into consideration that the concentration of this product in cosmetics was regulated in 2009. To explore risk factors for contact allergy to p-phenylenediamine. Material and methods Retrospective observational study of patients suspected of having contact dermatitis from allergy to p-phenylenediamine during the years between 2004 and 2015 in 8 tertiary level hospitals. The patients underwent patch testing (TRUE-test) with the standard series of the Spanish Research Group on Contact Dermatitis and Skin Allergies. This series included p-phenylenediamine 1%. We followed international recommendations for the statistical analysis of data related to contact allergies. Results Three hundred eighty-six out of 9341 patients (4.1%) had positive reactions to p-phenylenediamine. The prevalence tended to decrease in the early years (2004-2007) and then leveled off at around 4%. Risk factors for developing contact dermatitis from p-phenylenediamine were sex, age over 40 years, multiple sensitivities, and profession, notably workers in hair salons and those who handle rubber and plastics. Conclusions The prevalence of p-phenylenediamine allergy remains high among patients with contact eczema. Risk factors for p-phenylenediamine contact allergy are consistent with previous reports.

Condensation of p-phenylenediamine and glyoxal at a molar ratio of 1: 1 made it possible to synthesize a new polyimine with chelating ability. The complexation of this polyimine with transition metals was studied and the composition and structure of the complexes obtained were explored by means of IR, electron spectroscopy, EPR, derivatography, and elemental analysis.

A series of novel azacyclophanes consisting of 2,7-anthrylene and phenylene units were designed and synthesized by the Buchwald-Hartwig coupling reaction to investigate their unique electronic properties in multiple oxidized states. Cyclic voltammetry showed that the p-phenylene derivative exhibited three reversible oxidation waves, whereas the o- and m-phenylene derivatives showed two quasi-reversible oxidation waves due to the complicated intramolecular interaction between the oxidized units and neutral units. Moreover, the absorption spectra of the p-phenylene derivative in different oxidation states showed absorption bands at 865 and 1025 nm, which were attributed to intramolecular charge-transfer interactions. The photophysical and electrochemical properties of the p-phenylene analog were also compared with those of the o- and m-phenylene derivatives based on theoretical calculations for further evaluation of the intramolecular electronic interactions.

Thermal management has become an important requirement for many types of electrical equipment due to the development of integrated circuits. In this study, modified and reduced graphene fillers were synthesized in two steps, and then epoxy resin was filled through the evaporation of the solvent. The interfacial thermal resistance between the filler and matrix material was lowered by including amino groups to improve graphene compatibility in the epoxy resin. Furthermore, the reduction procedure was shown to have the potential to fix graphene oxide flaws, thereby improving thermal stability, electrical conductivity, and thermal conductivity of the composites. As a result, the thermal conductivity of the composite reached 1.7 W/mK, which is 750% higher than that of pure epoxy resin, and it was still insulated.

Polyanilines are an important class of organic compounds, due to their utility in a large variety of applications. In contrast, oligo­anilines have been employed far more sporadically, in large part reflecting an absence of refined synthetic approaches. Herein, we report, for the first time, a relatively large-scale strategy to generate highly pure aniline trimers at different oxidation states with excellent yields (90–97%).

Effective regulation of p-phenylenediamine (PPD), a widely used precursor of hair dye that is harmful to human health in large concentration, relies upon an accurate yet simple detection of PPD. In this context, amperometric electrode sensor based on perovskite oxide becomes attractive given its portability, low cost, high sensitivity, and rapid processing time. This work reports the systematic characterization of a series of Sr-doped PrCoO3-delta perovskite oxides with composition of Pr1-xSrxCoO3-delta (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) for PPD detection in an alkaline solution. PSC82 deposited onto glassy carbon electrode (PSC82/GCE) generates the highest redox currents which correlates with the highest hydrogen peroxide intermediates (HO2-) yield and the sigma*-orbital (e(g)) filling of Co that is closest to unity for PSC82. PSC82/GCE provides the highest sensitivities of 655 and 308 mu A mM(-1) cm(-2) in PPD concentration range of 0.5-2,900 and 2,900-10,400 mu M, respectively, with a limit of detection of 0.17 mu M. PSC82/GCE additionally demonstrates high selectivity to PPD and long term stability during 50 consecutive cyclic voltammetry scans and over 1-month storage period. The potential applicability of PSC82/GCE was also demonstrated by confirming the presence of very low concentration of PPD of below 0.5% in real hair dyes.

Hybrid supercapacitors using metal–organic frameworks (MOFs) exhibit high power and remarkable rate capability with consistent cyclability. The key limitations in developing MOF supercapacitors are the limited number of ligands and extensive laboratory protocols for synthesis. To solve these problems, we introduce the liquid–liquid interfacial reaction method for synthesising layered MOF using p-phenylenediamine (pPDA) building block as an organic ligand. The method is straightforward, consumes less energy and can be deployed in a small space at room temperature. We synthesise two types of layered MOFs, Ni-pPDA and Mn-pPDA, and fabricate hybrid supercapacitors by combining the positive MOF electrodes with a negative graphite carbon (GC) electrode. The supercapacitors using Ni-pPDA//GC and Mn-pPDA//GC exhibit high performances of approximately 184.7 F/g and 109.3 F/g, respectively. In particular, the Ni-pPDA supercapacitor exhibits high energy and power densities. The supercapacitors using Ni-pPDA and Mn-pPDA MOFs exhibit the capacitive retention of about 80% and 97%, respectively, after 5000 cycles.

In order to synthesize the high temperature solid lubricating film by gas-phase polymerization at 500 °C with two kinds of gasified monomers for use in airplane and rocket engines, the polymerizing...

The use of carboxylated graphene oxide (CGO) in the removal of organic pollutants from aquatic life is a recent and significant issue. In this study, EDTA-functionalized magnetite-carboxylated grap...

Currently, it remains controversial whether p-phenylenediamine (PPD) is genotoxic. In this study, we evaluated the potential genotoxicity of PPD using the newly-developed Pig-a gene mutation assay. The results of three classical genetic toxicity tests (bacterial reverse mutation assay, mammalian cell chromosomal aberration test, and mammalian erythrocyte micronucleus test) are all positive, suggesting that PPD is potentially genotoxic. In Pig-a assay, Sprague-Dawley rats are orally administered with PPD for 28 consecutive days at three doses (12.5, 25, and 50 mg/kg/day). Our result shows that PPD (25 and 50 mg/kg/day) dose-dependently increases RETCD59− value over controls on Day 8. RETCD59− keeps increasing to the maximum on Day 15 and then decreases until Day 29. PPD also dose-dependently increase RBCCD59− value on Day 15, which keeps elevating until Day 29. The time-course of RETCD59− and RBCCD59− induced by PPD are similar with that induced by N-ethyl-N-nitrosourea (ENU) treatment for 3 days. Our data suggests that PPD has potential genotoxic effects, and the Pig-a assay is sensitive to assess mutagenicity. However, further investigation of the changes of RETCD59− and RBCCD59− induced by hair dyes containing PPD should be detected by Pig-a assay in occupational exposure population to confirm the safety of PPD usage.

A sensitive spectrophotometric method (the N,N-diethyl-p-phenylenediamine (DPD) method) was established for the determination of trace permanganate concentration (0–10 μM) in water. The DPD method was based on the oxidative coloration reaction where permanganate could oxidize DPD to form the red colored DPD radical (DPD•+) with a second-order rate constant of 2.96 × 104 M−1 s−1 at pH 6 (50 mM phosphate buffer). The generated DPD•+ could be quantitatively measured at 551 nm using an UV–Vis spectrophotometer. There was a good linear relationship (R2 = 0.999) between the absorbance of DPD•+ and permanganate concentration. The DPD method was highly sensitive, and the absorbance of generated DPD•+ at 551 nm was as high as 5.70 × 104 cm−1 per M (mol L−1) of permanganate. The reaction of permanganate with DPD in the pH range of 4.0–8.0 had a stoichiometric coefficient of 1:2.71. The residual absorbance of DPD•+ in ultrapure water and natural waters was fairly stable for 30 min. Limits of detection of the proposed DPD method in ultrapure water and natural waters were calculated to be as low as 0.010 μM and 0.017 μM, respectively. Moreover, trace permanganate concentrations of 0.04 and 0.10 μM were found in natural waters and wastewater by the proposed DPD method. Additionally, the DPD method could be applied to measure the second-order rate constants of the reaction of permanganate with phenol at pH 7.0 (28.2 M−1 s−1).

Poly(aniline-co-p-phenylenediamine) cryogels stabilized by poly(vinyl alcohol) were prepared by one-step oxidative cryocopolymerization. Composite cryogels have macroporous structure with pore sizes up to tens of micrometers; however, copolymer cryogels have smaller pores compared to homopolymer cryogels. The cryogels containing 70 mol% and 80 mol% of aniline have the smallest pores and have the highest mechanical stability. The decrease in aniline fraction led to decrease of conductivity from 5×10–2 S cm–1 for polyaniline-based cryogel to

In this study, p-Phenylenediamine supported on nanocellulose (PDA@CNC) was designed. The prepared nanocatalyst was characterized with various analytical techniques such as FT-IR, XRD, TGA, SEM, and CHN. Nanocatalyst used for the synthesis of spiropyran oxide derivatives by designing a simple and efficient method using a three-part reaction between the Isatin derivatives, Malononitrile or Ethyl cyanoacetate and 1,3-dicarbonyl compound. Simple procedure, high yields, short reaction time and environmentally benign method are advantages of this protocol. The nanocatalyst was readily separated by filter and reusable without significant loss of its catalytic efficiency.

Background p -Phenylenediamine (PPD) is a common component of hair dye, indicating the clinical characteristics of skin contact allergy and asthma with impaired pulmonary function. Howerver the adverse effects of PPD occupational exposure was rarely mentioned. The purpose of this study was to explore the PPD-induced pulmonary function, pruritus and health-related quality of life (HRQOL) of industrial workers of hair dye. Methods We recruited 124 workers from a hair dye manufacturer exposed to PPD. Individual PPD exposure and pulmonary function of workers were measured. The quality of life and subjective pruritus of workers was also assessed by SF-36 and VAS of pruritus, respectively. Results In the high PPD-exposed group, FVC% (percentage of forced vital capacity) was higher, while FEV1/FVC% (ratio percentage of forced expiratory volume) was lower than that in the low PPD-exposed group ( P

Background: Allergic contact dermatitis caused by p-phenylenediamine (PPD) is a health concern for hair dye users. Because of its lower sensitization potency, the PPD derivative 2-methoxymethyl-p-phenylenediamine (ME-PPD) has been developed as an alternative hair dye for primary prevention. However, cross-elicitation responses can occur in PPD-allergic subjects.Objectives: To compare cross-elicitation responses to ME-PPD in open use and diagnostic patch testing of PPD-allergic subjects with hair dye-related allergic contact dermatitis.Methods: Reactions to ME-PPD were investigated in 25 PPD-allergic subjects by performing (1) 45-minute open use testing with a hair dye containing 2.0% of either ME-PPD or PPD, and (2) patch testing with increasing ME-PPD concentrations (0.1%-2.0% pet.).Results: Of the 25 PPD-allergic subjects, 21 (84%) reacted to open use testing with a hair dye containing 2.0% PPD, and testing with 2.0% ME-PPD led to cross-elicitation in 12 (48%). When patch tested with increasing ME-PPD concentrations, 13 (52%) cross-reacted at 0.1% (lowest dose) and 21 (84%) at 2.0% (highest dose), indicating decreased reactivity as compared with published PPD dose-response data.Conclusion: In line with the decreased cross-reactivity of ME-PPD in hair dye open use testing, PPD-allergic subjects show an attenuated cross-elicitation dose response to ME-PPD in patch testing.

Background Contact dermatitis to hair dyes remains a health concern. Regulations in many countries require consumer self-testing for hair dyes, but no standardized procedure exists.Objective The aim of this study was to develop a self-test protocol for an allergy alert test (AAT) that can elicit a self-noticeable alert signal in p-phenylenediamine (PPD)-allergic consumers.Methods Simulating consumer use conditions (open application for 45 minutes after mixing with a developer), PPD-positive hair dye-allergic subjects and PPD-negative control subjects were tested on the forearm and behind the ear with experimental products containing 0.05%, 0.25%, 0.75%, and 2% PPD. Reactions were self-evaluated by subjects and independently assessed by dermatologists.Conclusions The AAT caused a reaction self-noticeable on the forearm in 90.5% (38/42) and behind the ear in 93% (39/42) of the PPD-positive subjects. This was objectified by a dermatological evaluation. The strength of the AAT response and the number of responding subjects increased with increasing PPD concentrations. Allergy alert test responses were also dependent on the reaction strength of the diagnostic patch test to PPD before the study; in subjects with (+++) patch test reactions, 19 of 19 were positive. All 48 control subjects were negative to the AAT. Therefore, the AAT protocol provides a signal indicative of an allergic reaction in PPD-allergic hair dye consumers.

Nitrogen-containing carbon derivatives were prepared by the carbonization of poly(aniline-co-p-phenylenediamine) cryogels in inert atmosphere. Lower aniline fraction in the comonomer mixture used for preparation of the cryogels led to the decrease of their thermal stability, a consequent increase of carbonization degree, and less defective structure of carbonized materials. The resulting carbonaceous products had up to 4 orders of magnitude higher specific surface area than their respective cryogel precursors, the highest value 931 m2 g&minus, 1 being achieved for carbonized poly(p-phenylenediamine) cryogel. Electrochemical characterization of the carbon derivatives demonstrated that the decrease in aniline concentration during the synthesis of the precursor cryogels led to higher gravimetric capacitance for corresponding carbonized materials. These materials can potentially be used for energy storage applications.

In present work, we developed luminescent carbon dots for the analytical determination of chromium(III) in food supplement samples. For this purpose, carbon dots were synthesized by the solvothermic method using ethanol from p-phenylenediamine as a precursor. The PC obtained was purified in a chromatographic column and characterized by transmission electron microscopy (TEM), Fourier Transform Infrared Absorption Spectroscopy (FTIR), X-ray Excited Photoelectron Spectroscopy (XPS), UV-Visible Spectroscopy (UV- VIS) as well as luminescence spectroscopy. The PC obtained showed intense emission in red color, presenting a quantum yield equal to 11.3%. The characterizations carried out allowed to relate the observed emission to the carbon point surface characteristics, such like the content of chemical species containing oxygen and the presence of groups such as COOH. The application of the material for the quantification of chromium(III) ions was feasible, with a linear response between 4 and 20 mg L1 of chromium(III) ions. The results of the statistical analysis, for a confidence level of 95 %, suggested that the proposed method does not present significant difference, when compared to the method by energy dispersion X-ray spectroscopy, for the determination of chromium(III) ions in chromium(III) picolinate supplement samples. Nenhuma Nesse trabalho foram estudados, pontos de carbono luminescentes para a determinação quantitativa de cromo (III) em amostras de suplemento alimentar. Para esse propósito, os pontos de carbono foram sintetizados pelo método solvotérmico, utilizando etanol, a partir da parafenilenodiamina como precursor. O PC obtido foi purificado em coluna cromatográfica e caracterizado por microscopia eletrônica de transmissão (TEM), espectroscopia de absorção na região do infravermelho com transformada de Fourier (FTIR), espectroscopia de fotoelétrons excitados por raios X (XPS), espectroscopia na região do ultravioleta-visível (UV-Vis), bem como espectroscopia de luminescência. O PC exibiu intensa emissão na cor vermelha, apresentando um rendimento quântico igual a 11,3 %. As caracterizações realizadas permitiram relacionar a emissão observada a características da superfície do ponto de carbono, como a presença de espécies químicas contendo oxigênio e a presença de grupos como COOH. A aplicação do material para a quantificação de íons cromo(III) mostrou-se viável, sendo observada uma resposta linear entre 4 e 20 mg L1 de íons cromo(III). Os resultados da análise estatística, para um nível de confiança de 95 %, sugeriram que o método proposto não apresenta diferença significativa, quando comparado ao método por espectroscopia de raios X por dispersão em energia, para a determinação de íons cromo(III) em amostras de suplementos contendo picolinato de cromo (III).

Background. Polysensitization, defined as being allergic to three or more haptens from the European baseline series, is considered to reflect increased susceptibility to developing a contact allergy, and is likely to be associated with an impaired quality of life.Objectives. To evaluate the prevalences of polysensitization across Europe and to analyse factors associated with polysensitization.Methods. Patch test data collected by the European Surveillance System on Contact Allergies (ESSCA; www.essca-dc.org) in consecutively patch tested patients from January 2009 to December 2014, comprising 11 countries and 57 departments, were retrospectively analysed.Results. A total of 86 416 patients were available for analysis, showing a standardized prevalence of polysensitization of 7.02%, ranging from 12.7% (Austria) to 4.6% (Italy). Allergen pairs with the strongest association are reported for the total population, for South Europe, and for North/Central Europe. Overall, polysensitized patients showed a higher percentage of extreme (+++) positive patch test reactions than oligosensitized patients. Female sex, occupational dermatitis and age > 40 years were risk factors for polysensitization.Conclusions. The varying prevalences of polysensitization across Europe most likely reflect differences in patient characteristics and referral patterns between departments. Knownrisk factors for polysensitization are confirmed in a European dermatitis population.

Occupational exposure of hairdressers to hair dyes has been associated with the development of allergic contact dermatitis (ACD) involving the hands. p-Phenylenediamine (PPD) and toluene-2,5-diamine (PTD) have been implicated as important occupational contact allergens. To conduct a quantitative risk assessment for the induction of contact sensitization to hair dyes in hairdressers, available data from hand rinsing studies following typical occupational exposure conditions to PPD, PTD and resorcinol were assessed. By accounting for wet work, uneven exposure and inter-individual variability for professionals, daily hand exposure concentrations were derived. Secondly, daily hand exposure was compared with the sensitization induction potency of the individual hair dye defined as the No Expected Sensitization Induction Levels (NESIL). For PPD and PTD hairdresser hand exposure levels were 2.7 and 5.9 fold below the individual NESIL. In contrast, hand exposure to resorcinol was 50 fold below the NESIL. Correspondingly, the risk assessment for PPD and PTD indicates that contact sensitization may occur, when skin protection and skin care are not rigorously applied. We conclude that awareness of health risks associated with occupational exposure to hair dyes, and of the importance of adequate protective measures, should be emphasized more fully during hairdresser education and training.

The new nanocrystalline composition was synthesized using NiSO4 and MoO3 and PPDA (p-phenylenediamine) via the hydrothermal method. The structure, morphology and photoluminescence property of nanocrystal were studied using X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) spectra, thermogravimetric analysis (TGA–DTA) and energy-dispersive X-ray spectroscopy (EDX). The effect of factors such as type and concentration of initial materials, pH values, temperature and reaction duration on the structure and morphology of nanocrystals was investigated in the preparation of composition. The results show that the pH of the initial solution affects the size of the prepared nanocrystals; the size of the crystals is increased and the morphology of the nanostructures is changed with the increment in pH value. According to the obtained results, neutral or low alkaline conditions of pH are more favorable for the formation of the nanocrystals. The obtained nanocrystal shows an intense PL emission at room temperature with a maximum peak at 461 nm and excitation at the wavelength of 300 nm. TGA and DTA analysis display a total weight loss of 13.42%.

Made available in DSpace on 2018-12-11T17:36:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 Currently, little information is available regarding the presence of compounds from raw hair dyeing wastewater. It is known that the most commonly commercial formulations contain components with toxic properties and some by-products may also be mutagenic and carcinogenic. Indeed, virtually no studies can be found in the literature dealing with the treatment of such effluents and identification of environmental concerning substances, such as p-phenylenediamine, resorcinol and Bandrowski's base. The present work sought to evaluate the treatment of real hair dyeing effluent through different combinations of advanced oxidation processes including ozonation (O3), ozone/UV-C (O3/UV), ozone/photoelectrocatalysis (O3/PEC), O3/UV/H2O2 and O3/PEC/H2O2. O3/PEC/H2O2 combination provided almost complete mineralization while ozonation promoted less than 50% after 90min of treatment. HPLC analysis confirmed the presence of p-phenylenediamine, resorcinol and Bandrowski's base in the raw effluent, which were completely removed in less than 5min of treatment through the application of the combined O3/PEC/H2O2 process. A figure of merit, the electric energy per order, was used to compare the different methods, showing that O3/PEC/H2O2 provides lower energy consumption and higher mineralization, and could thus be an efficient option for wastewater treatment. Universidade Estadual Paulista (Unesp) Instituto de Química, Araraquara. Av. Prof. Francisco Degni, 55 Universidade Estadual Paulista (Unesp) Instituto de Química, Araraquara. Av. Prof. Francisco Degni, 55

Background Concern about causing active sensitization when patch testing is performed with p-phenylenediamine (PPD) 1% pet. has led to a recommendation to use PPD 0.3% pet. as a potentially safer preparation. However, the dose per area of allergen delivered, and hence the risk of active sensitization, depend on the amount dispensed into the patch test chamber, which can vary widely. Objective To evaluate whether patch testing with equivalent doses of different concentrations of PPD in pet. is associated with similar outcomes. Methods Seventeen known PPD-sensitive subjects were patch tested with different volumes and concentrations of PPD in pet. that deliver the same allergen dose per unit area (6 mg of PPD 1% pet. and 20 mg of PPD 0.3% pet. in Finn Chambers®, both equivalent to ∼ 0.09 mg/cm2 ). Results Eleven patients (65%) had positive reactions to both doses; 4 patients (24%) had negative results [percentage agreement of 88% (15/17)]. One patient each had a positive reaction to only one dose. Conclusions The 88% concordance suggests that dose per unit area is more important in determining reactions to allergens than the excipient volume dispensed. Patch testing with a smaller volume of 1% PPD may be a reasonable alternative to testing with 20 mg of 0.3% PPD.

Background Risk factors for p-phenylenediamine (PPD) sensitization include the use of hair dyes, the application of temporary black henna tattoos, working as a hairdresser, and, possibly, exposure to hair dye pretests. Objectives To quantify the impact of these (putative) risk factors on PPD sensitization. Methods Six items related to PPD exposure were added to the routine Information Network of Departments of Dermatology questionnaire from 2008 to 2013. A retrospective analysis of data from 4314 patients tested with PPD 1% pet. was conducted. Results Of the PPD-positive patients (n = 271), 80% had their hair dyed, and, of these, 57% subsequently developed scalp dermatitis, whereas only 11% had had a henna tattoo. The self-administrated pretest with hair dye was performed by only a few patients, precluding a more detailed analysis. Hair dyeing [odds ratio (OR) 6.0; 95% confidence interval (CI): 3.9-9.4], henna tattoos (OR 2.4; 95%CI: 1.5-3.7) and being a hairdresser (OR 2.1; 95%CI: 1.3-3.2) increased the risk of PPD sensitization. Neither dyeing of own hair nor application of a temporary henna tattoo seemed to affect PPD sensitization in hairdressers. p-Aminoaryl compounds more often gave positive reactions in patients with henna tattoo. Conclusions Hair dyeing is the major risk factor for PPD sensitization in this clinical setting, and application of a temporary black henna tattoo may also lead to (strong) PPD sensitization.

Physical-chemical considerations suggest that the diene rubber olefinic double bonds protection by N,N′-substituted p-phenylenediamines (PPDs) antiozonants (AOZs) is due to their very low ionization potential in comparison to the ionization potential of the olefinic double bonds. Thus, the ozone scavenging action exerted by PPDs AOZs is due to one electron transfer from the PPDs to the ozone molecule with the formation of the PPDs radical cation. Furthermore, Hammett-type plot of the reaction rate with ozone of a series of aromatic amines including also N,N′-substituted PPDs suggests that the result of ozone oxidation is the formation of PPDs radical cations. In the present study, a series of common N,N′-substituted PPDs used as AOZs in rubber compounds were oxidized with ozone in trichloromethane and/or o-dichlorobenzene solutions and studied with Electron Spin Resonance (ESR). Experimental evidences about the radical cation formation and the subsequent almost quantitative PPDs nitroxyl radical formation as a result of the reaction of PPDs radical cation with ozone radical anion were collected and support experimentally the physical-chemical premises. Upon addition of trichloroacetic acid to the PPDs nitroxyl radical solutions, the immediate decomposition of the nitroxyl radical and the formation of stabilized PPDs radical cation was observed.