Objective: To analyze correlation of occupational hydrogen fluoride exposure to low doses of bone metabolism index through occupational epidemiological investigation and benchmark dose calculation. Methods: In May 2021, using cluster sampling method, 237 workers exposed to hydrogen fluoride in a company were selected as the contact group, and 83 workers not exposed to hydrogen fluoride in an electronics production company were selected as the control group. The external exposure dose and urinary fluoride concentration, blood and urine biochemical indicators of the workers was measured.The relationship between external dose and internal dose of hydrogen fluoride was analyzed. The external dose, urinary fluoride was used as exposure biomarkers, while serum osteocalcin (BGP), serum alkaline phosphatase (AKP) and urinary hydroxyproline (HYP) were used as effect biomarkers for bone metabolism of hydrogen fluoride exposure. The benchmark dose calculation software (BMDS1.3.2) was used to calculate benchmark dose (BMD) . Results: Urine fluoride concentration in the contact group was correlated with creatinine-adjusted urine fluoride concentration (r=0.69, P=0.001). There was no significant correlation between the external dose of hydrogen fluoride and urine fluoride in the contact group (r=0.03, P=0.132). The concentrations of urine fluoride in the contact group and the control group were (0.81±0.61) and (0.45±0.14) mg/L, respectively, and the difference between the two groups was statistically significant (t=5.01, P=0.025). Using BGP, AKP and HYP as effect indexes, the urinary BMDL-05 values were 1.28, 1.47 and 1.08 mg/L, respectively. Conclusion: Urinary fluoride can sensitively reflect the changes in the effect indexes of biochemical indexes of bone metabolism. BGP and HYP can be used as early sensitive effect indexes of occupational hydrogen fluoride exposure.
Humans ; Fluorides/adverse effects* ; Hydrofluoric Acid ; Benchmarking ; Biomarkers ; Occupational Exposure/adverse effects*

Hydrofluoric acid is a highly dangerous and toxic inorganic acid, which is widely used in industrial fields and daily life. The risk of hydrofluoric acid burns is related to hydrofluoric acid mass fraction, duration of exposure to hydrofluoric acid, burn area, burn depth, and burn site, etc. Hydrofluoric acid has strong toxicity and tissue penetration ability. A small area of hydrofluoric acid burns can cause death in a short time. Therefore, improving the understanding of the mechanism of hydrofluoric acid burns and learning how to treat hydrofluoric acid burns in different sites can further improve the cure rate of hydrofluoric acid burns.
Burns, Chemical/therapy* ; Calcium Gluconate ; Humans ; Hydrofluoric Acid/adverse effects*

Objective: Using CFD technology to grasp the distribution and diffusion of hydrogen fluoride in an electrolytic fluorine plant, provide guidance and scientific basis for enterprises to carry out occupational health management in enterprises, install hazardous substance alarm devices, and protect workers' occupational health. Methods: In July 2019, the diffusion law of hydrogen fluoride gas produced in an electrolytic fluorine plant is selected as the research object. Through the establishment of models and grids, the Fluent numerical simulation method is finally used to simulate the diffusion and distribution of hydrogen fluoride gas under ventilation conditions. Results: The results showed that the average concentration of hydrogen fluoride was 0.045 mg/m(3) in the workplace, and the absorbed zone height (1.5 m) was 0.02 mg/m(3) in the inspection channel, which was in accordance with the national standard. However, there is eddy current above the electrolyzer near the inlet, may lead to the accumulation of hydrogen fluoride gas. Conclusion: The research of CFD numerical simulation method on the distribution and diffusion of hydrogen fluoride concentration in electrolytic fluorine plant can be applied to the prevention, control and management of occupational hazards in electrolytic fluorine plant.
Computer Simulation ; Fluorides ; Humans ; Hydrofluoric Acid ; Occupational Exposure/prevention & control* ; Occupational Health

Objective: To explore the epidemiological characteristics and treatment outcomes of patients with hydrofluoric acid burns in hands. Methods: A retrospective observational study was conducted. The medical records of 229 patients with hydrofluoric acid burns in hands who were admitted to Zhejiang Quhua Hospital from January 2008 to December 2020 and met the inclusion criteria were collected. The following statistical data of patients were collected, including gender, age, type of affiliated enterprise, hydrofluoric acid mass fraction, injury site, total burn area, prehospital time, length of hospital stay, length of wound healing, whether hypocalcemia and hypomagnesemia occurred or not on admission, whether surgery intervention was performed or not, and whether scar sequelae occurred or not. Single factor and multivariate logistic regression analysis were used to screen out the risk factors impacting surgery intervention and scar sequelae of all the patients and patients whose hydrofluoric acid mass fraction was known. Single factor and multivariate linear regression analysis were used to screen out the risk factors impacting the length of wound healing of all the patients and patients whose hydrofluoric acid mass fraction was known. Results: The 229 patients included 206 males and 23 females, with the majority aged 30 to 50 years (139 patients). The type of affiliated enterprise of majority patients was non-fluorine chemical enterprise. The hydrofluoric acid mass fraction was known in only 91 patients, mainly medium. The majority injury site was in the middle and end of finger. The total burn area was below or equal to 1% total body surface area. The prehospital time was 19 (9, 29) h. The length of hospital stay was 2 (1, 7) d. The length of wound healing was 12 (8, 18) d. The proportions of hypocalcemia and hypomagnesemia were 0.9% (2/229) and 1.3% (3/229) on admission, respectively. Thirty-six patients had surgeries and 83 patients had scar sequelae. In 229 patients, single factor logistic regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting surgery intervention (with odds ratio values of 7.86 and 51.35, respectively, 95% confidence intervals of 1.83-33.76 and 11.89-221.78, respectively, P<0.01) and scar sequelae of patients (with odds ratio values of 3.62 and 27.40, respectively, 95% confidence intervals of 1.76-7.43 and 13.25-56.68, respectively, P<0.01); multivariate logistic regression analysis showed that prehospital time was the independent risks factor impacting surgery intervention and scar sequelae of patients (with odds ratio values of 43.00 and 24.55, respectively, 95% confidence intervals of 9.89-187.03 and 11.78-51.16, respectively, P<0.01); single factor linear regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting the length of wound healing of patients (with β values of 6.16 and 12.83, respectively, 95% confidence intervals of 3.38-8.93 and 10.72-14.93, respectively, P<0.01); multivariate linear regression analysis showed that both type of affiliated enterprise and prehospital time were the independent risk factors impacting the length of wound healing of patients (with β values of 2.81 and 12.16, respectively, 95% confidence intervals of 0.50-5.13 and 10.00-14.31, respectively, P<0.05 or P<0.01). In 91 patients whose hydrofluoric acid mass fraction was known, single factor logistic regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting surgery intervention of patients (with odds ratio values of 9.10, 11.25, 10.69, and 0.04, respectively, 95% confidence intervals of 1.15-72.25, 1.39-90.93, 1.32-86.59, and 0.01-0.19, respectively, P<0.05 or P<0.01), type of affiliated enterprise, hydrofluoric acid mass fraction, and prehospital time were all the factors impacting scar sequelae of patients (with odds ratio values of 0.32, 0.21, and 36.80, respectively, 95% confidence intervals of 0.11-0.92, 0.06-0.73, and 11.03-122.79, respectively, P<0.05 or P<0.01); multivariate logistic regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting surgery intervention of patients (with odds ratio values of 11.51 and 0.04, respectively, 95% confidence intervals of 1.22-108.26 and 0.01-0.25, respectively, P<0.05 or P<0.01), prehospital time was the independent risk factor impacting scar sequelae of patients (odds ratio=37.71, with 95% confidence interval of 9.97-142.69, P<0.01); single factor linear regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting the length of wound healing of patients (with β values of 7.12, -5.63, -9.74, and 13.50, respectively, 95% confidence intervals of 2.43-11.81, -10.59--0.68, -14.78--4.70, and 10.14-16.86, respectively, P<0.05 or P<0.01); multivariate linear regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting the length of wound healing of patients (with β values of -5.84 and 0.09, respectively, 95% confidence intervals of -10.59--1.08 and 0.05-0.12, respectively, P<0.05 or P<0.01). Conclusions: The majority of patients with hydrofluoric acid burns in hands are young and middle-aged males. Type of affiliated enterprise, hydrofluoric acid mass fraction and prehospital time are the risk factors that affect the treatment outcomes of patients with hydrofluoric acid burns in hands.
Adult ; Body Surface Area ; Burns ; Female ; Humans ; Hydrofluoric Acid/adverse effects* ; Length of Stay ; Male ; Middle Aged ; Retrospective Studies ; Treatment Outcome

OBJECTIVES: This study investigated the effects of a hydrofluoric acid (HA; solution of hydrogen fluoride [HF] in water)-based smart etching (SE) solution at an elevated temperature on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in terms of bond strength and morphological changes.MATERIALS AND METHODS: Eighty sintered Y-TZP specimens were prepared for shear bond strength (SBS) testing. The bonding surface of the Y-TZP specimens was treated with 37% phosphoric acid etching at 20°C–25°C, 4% HA etching at 20°C–25°C, or HA-based SE at 70°C–80°C. In all groups, zirconia primers were applied to the bonding surface of Y-TZP. For each group, 2 types of resin cement (with or without methacryloyloxydecyl dihydrogen phosphate [MDP]) were used. SBS testing was performed. Topographic changes of the etched Y-TZP surface were analyzed using scanning electron microscopy and atomic force microscopy. The results were analyzed and compared using 2-way analysis of variance.RESULTS: Regardless of the type of resin cement, the highest bond strength was measured in the SE group, with significant differences compared to the other groups (p < 0.05). In all groups, MDP-containing resin cement yielded significantly higher bond strength values than MDP-free resin cement (p < 0.05). It was also shown that the Y-TZP surface was etched by the SE solution, causing a large change in the surface topography.CONCLUSIONS: Bond strength significantly improved when a heated HA-based SE solution was applied to the Y-TZP surface, and the etched Y-TZP surface was more irregular and had higher surface roughness.
Ceramics ; Hot Temperature ; Hydrofluoric Acid ; Microscopy, Atomic Force ; Microscopy, Electron, Scanning ; Resin Cements

PURPOSE: The aim of this study was to evaluate the microshear bond strength (µSBS) of four computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three different surface treatment protocols.MATERIALS AND METHODS: Four different CAD/CAM blocks were used in this study: (1) flexible hybrid ceramic (FHC), (2) resin nanoceramic (RNC), (c) polymer infiltrated ceramic network (PICN) and (4) feldspar ceramic (FC). All groups were further divided into four subgroups according to surface treatment: control, hydrofluoric acid etching (HF), air-borne particle abrasion with aluminum oxide (AlO), and tribochemical silica coating (TSC). After surface treatments, silane was applied to half of the specimens. Then, a silane-containing universal adhesive was applied, and specimens were repaired with a composite, Next, μSBS test was performed. Additional specimens were examined with a contact profilometer and scanning electron microscopy. The data were analyzed with ANOVA and Tukey tests.RESULTS: The findings revealed that silane application yielded higher µSBS values (P<.05). All surface treatments were showed a significant increase in µSBS values compared to the control (P<.05). For FHC and RNC, the most influential treatments were AlO and TSC (P<.05).CONCLUSION: Surface treatment is mandatory when the silane is not preferred, but the best bond strength values were obtained with the combination of surface treatment and silane application. HF provides improved bond strength when the ceramic content of material increases, whereas AlO and TSC gives improved bond strength when the composite content of material increases.
Adhesives ; Aluminum Oxide ; Ceramics ; Clinical Protocols ; Dental Bonding ; Dental Restoration Repair ; Hydrofluoric Acid ; Microscopy, Electron, Scanning ; Polymers ; Shear Strength ; Silicon Dioxide

The computer-aided design/computer-aided manufacturing (CAD/CAM) system was introduced to shorten the production time of all-ceramic restorations and the number of patient visits. Among these types of ceramic for dental CAD/CAM, they have been processed into inlay, onlay, and crown shapes using leucite-reinforced glass-ceramics to improve strength. The purpose of this study was to observe the mechanical properties and microstructure of leucite-reinforced glass-ceramics for dental CAD/CAM. Two types of leucite-reinforced glass-ceramic blocks (IPS Empress CAD, Rosetta BM) were prepared with diameter of 13 mm and thickness of 1 mm. Biaxial flexural testing was conducted using a piston-on-three-ball method at a crosshead speed of 0.5 mm/min. Weibull statistics were used for the analysis of biaxial flexural strength. Fracture toughness was obtained using an indentation fracture method. Specimens were observed by field emission scanning electron microscopy to examine the microstructure of the leucite crystalline phase after acid etching with 0.5% hydrofluoric acid aqueous solution for 1 minute. The results of strength testing showed that IPS Empress CAD had a mean value of 158.1±8.6 MPa and Rosetta BM of 172.3±8.3 MPa. The fracture toughness results showed that IPS Empress CAD had a mean value of 1.28±0.19 MPa·m(1/2) and Rosetta BM of 1.38±0.12 MPa·m(1/2). The Rosetta BM sample exhibited higher strength and fracture toughness. Moreover, the crystalline phase size and ratio were increased in the Rosetta BM sample. The above results are expected to elucidate the basic mechanical properties and crystal structure characteristics of IPS Empress CAD and Rosetta BM. Additionally, they will help develop leucite-reinforced glass-ceramic materials for CAD/CAM.
Ceramics ; Crowns ; Crystallins ; Humans ; Hydrofluoric Acid ; Inlays ; Methods ; Microscopy, Electron, Scanning

We reviewed the chemical/physical properties, toxicity, environmental fate, and ecotoxicity of strong acids in soil and groundwater environments. We recommend that sulfuric acid and hydrofluoric acid be classified as chemicals of priority control based on volumes used, toxicity, carcinogenicity, and past significant spill events. Understanding the behavior and transport of spilled strong acids in soil and groundwater environments requires a multi-disciplinary approach, as they can undergo a variety of geochemical and biochemical reactions with complex geomedia. The toxicity of spilled acid is dependent on the characteristics of the geomedia exposed to the acid and the amount of residual protons following acid–substrate interaction. Soil texture, cation exchange capacity, mineral composition, bedrock type, and aluminum content may be important factors affecting the toxicity of spilled acid in soil-groundwater environments. We expect that the results of this study will contribute preliminary data for future research on chemical spills.
Aluminum ; Groundwater* ; Hydrofluoric Acid ; Miners ; Protons ; Soil* ; Sulfur

BACKGROUND: Resilient individuals have a comprehensive ability to adapt to various life circumstances. Psychological resilience predicts an individual’s physiological response to stress. The 10-item Connor-Davidson Resilience Scale (CD-RISC) is a widely used measure to quantify the level of self-perceived resilience. This study examined the psychometric properties of a Korean version of the 10-item Connor-Davidson Resilience Scale (10-item K-CD-RISC) on workers in Gumi, South Korea, exposed to hydrofluoric acid (HF). METHODS: The questionnaires included the 10-item K-CD-RISC and Beck Anxiety Inventor (BAI), the Impact of Event Scale-Revised-Korean version (IES-R-K), the Rosen-berg Self Esteem Scale (RSES), the Center for Epidemiologic Studies-Depression Scale (CES-D), and the Perceived Stress Scale (PSS). These were randomly distributed at 237 workplaces near the HF-spill site, in the Gumi 4 complex. The responses of 991 (67.3%) workers were analyzed. RESULTS: The exploratory factor analysis shown that a single-factor model was consistent with the original design of the 10-item CD-RISC. The scale also demonstrated good internal consistency (Cronbach’s alpha = 0.95). Scores on the scale reflected different levels of resilience with respect to personal factors (age, gender, marital status, and education and income levels) that are thought to be differentiated. Differences of resilience were also reflected by psychiatric symptoms (anxiety and depression). Moreover, the total score of scale positively correlated with RSES, whereas the IES-R-K, BAI, CES-D, and the PSS negatively correlated with the 10-item K-CD-RISC. CONCLUSIONS: The 10-item K-CD-RISC has good psychometric properties and is applicable for victims exposed to noxious chemical such as HF.
Anxiety ; Education ; Gyeongsangbuk-do ; Humans ; Hydrofluoric Acid ; Inventors ; Korea ; Marital Status ; Psychometrics ; Resilience, Psychological ; Self Concept ; Stress Disorders, Post-Traumatic

We reviewed the chemical/physical properties, toxicity, environmental fate, and ecotoxicity of strong acids in soil and groundwater environments. We recommend that sulfuric acid and hydrofluoric acid be classified as chemicals of priority control based on volumes used, toxicity, carcinogenicity, and past significant spill events. Understanding the behavior and transport of spilled strong acids in soil and groundwater environments requires a multi-disciplinary approach, as they can undergo a variety of geochemical and biochemical reactions with complex geomedia. The toxicity of spilled acid is dependent on the characteristics of the geomedia exposed to the acid and the amount of residual protons following acid–substrate interaction. Soil texture, cation exchange capacity, mineral composition, bedrock type, and aluminum content may be important factors affecting the toxicity of spilled acid in soil-groundwater environments. We expect that the results of this study will contribute preliminary data for future research on chemical spills.
Aluminum ; Groundwater ; Hydrofluoric Acid ; Miners ; Protons ; Soil ; Sulfur