Size-Resolved Characterization of Particles and Fibers Released during Abrasion of Fiber-Reinforced Composite in a Workplace Influenced by Ambient Background Sources

Kling, Kirsten Inga; Levin, Marcus; Jensen, Alexander C. Ø.; Jensen, Keld Alstrup; Koponen, Ismo K.

doi:10.4209/aaqr.2015.05.0295

Cited by 10 publications

(6 citation statements)

References 30 publications

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“…This sampling technique has been used successfully in environmental Kandler et al, 2011;Nguyen et al, 2017), occupational (Jensen et al, 2015;Kling et al, 2016;Koivisto et al, 2018), and combustion particle studies (Lieke et al, 2013). The Micro Inertial Impactor samples particles up to ca.…”

Section: Particle Sampling and Characterizationmentioning

confidence: 99%

Occupational exposure during handling and loading of halloysite nanotubes – A case study of counting nanofibers

et al. 2018

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A B S T R A C THalloysite nanotubes (HNTs) are abundant naturally-occurring hollow aluminosilicate clay mineral fibers with a typical diameter < 100 nm and an aspect ratio of up to 200. Here we assessed the potential inhalation exposure to HNTs in an industrial research laboratory. Inside a fume hood, ten times 100 g of HNTs were poured at rate of 0.5 kg min . Inside the fume hood, the respirable mass concentration was 143 μg m −3 including background particles.Outside the fume hood we did not measure elevated concentrations. We classified 1895 particles according to their length and aspect ratio. Five particles were in aspect ratio > 3 and in length > 2 μm. These particles were agglomerated and/or aggregated particles where the longest individual fiber was 2 μm in length. The occupational exposure limits for refractory mineral fibers vary from 0.1 to 2 fibers cm −3. Following standard protocols for fiber analysis, detection of 0.1 fibers cm −3 would require analysis on 4 × 10 4 images when the filter loading is good. Thus, the fiber sampling and quantification procedures needs to be improved significantly if nanofibers < 100 nm in diameter are included in regulatory exposure assessment. Due to very limited toxicological information of HNTs we recommend avoiding inhalation exposure.

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Section: Particle Sampling and Characterizationmentioning

confidence: 99%

Occupational exposure during handling and loading of halloysite nanotubes – A case study of counting nanofibers

et al. 2018

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“…Knowledge is currently developing on the process-specific particle emissions and release of fibrous nanomaterials during the life-cycle processes (e.g., sanding, weathering, shredding, and incineration) of carbon-based nanocomposites. Recently, it was shown that significant fractions of carbon fibers of μm-size diameters were clearly separated from matrix during industrial-scale grinding and sanding of layered silica-carbon epoxy composite [ 16 ]. Conversely, sanding of dispersed epoxy/CNT nanocomposite, using a smaller hand-held sander in laboratory setup produced only dust epoxy particles with protruding CNT [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

Epoxy composite dusts with and without carbon nanotubes cause similar pulmonary responses, but differences in liver histology in mice following pulmonary deposition

et al. 2015

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BackgroundThe toxicity of dusts from mechanical abrasion of multi-walled carbon nanotube (CNT) epoxy nanocomposites is unknown. We compared the toxic effects of dusts generated by sanding of epoxy composites with and without CNT. The used CNT type was included for comparison.MethodsMice received a single intratracheal instillation of 18, 54 and 162 μg of CNT or 54, 162 and 486 μg of the sanding dust from epoxy composite with and without CNT. DNA damage in lung and liver, lung inflammation and liver histology were evaluated 1, 3 and 28 days after intratracheal instillation. Furthermore, the mRNA expression of interleukin 6 and heme oxygenase 1 was measured in the lungs and serum amyloid A1 in the liver. Printex 90 carbon black was included as a reference particle.ResultsPulmonary exposure to CNT and all dusts obtained by sanding epoxy composite boards resulted in recruitment of inflammatory cells into lung lumen: On day 1 after instillation these cells were primarily neutrophils but on day 3, eosinophils contributed significantly to the cell population. There were still increased numbers of neutrophils 28 days after intratracheal instillation of the highest dose of the epoxy dusts. Both CNT and epoxy dusts induced DNA damage in lung tissue up to 3 days after intratracheal instillation but not in liver tissue. There was no additive effect of adding CNT to epoxy resins for any of the pulmonary endpoints. In livers of mice instilled with CNT and epoxy dust with CNTs inflammatory and necrotic histological changes were observed, however, not in mice instilled with epoxy dust without CNT.ConclusionsPulmonary deposition of epoxy dusts with and without CNT induced inflammation and DNA damage in lung tissue. There was no additive effect of adding CNT to epoxies for any of the pulmonary endpoints. However, hepatic inflammatory and necrotic histopathological changes were seen in mice instilled with sanding dust from CNT-containing epoxy but not in mice instilled with reference epoxy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12989-016-0148-2) contains supplementary material, which is available to authorized users.

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“…Carbon composites have become a crucial component in modern technology, with numerous applications in military, civilian, energy, medical, and environmental fields. Polymer composites, made with affordable materials and equipment, are easy to produce and offer both process ability and cost-effectiveness [5][6][7].Composite materials are produced by combining or merging different materials or qualities in which the component elements are individually distinct, or, two or more phases combined physically, which result in a new material that has excellent features if compared to the features of the individual phases [8][9][10].In opposing to alloys, every phase of composites keeps its distinguished physical, mechanical, and chemical properties [9,11,12].The essential utilities of composites are good stiffness, high specific strength, and good electrical and thermal properties results. In addition to lightweights when they are compared with alloys or ceramics products [13,14].…”

Section: Introductionmentioning

confidence: 99%

The role of Palm Fronds Charcoal Waste Particles On Mechanical, Thermal, and Acoustic Insulation Properties of Epoxy Composite

Ahmed,

Kadim

2024

J. Phys.: Conf. Ser.

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The main objectives of the current study are to improve the mechanical, thermal, physical and sound insulation properties of an epoxy composite, in addition to reducing environmental pollution resulting from the burning of palm kernel waste, which results from annual periodic cleaning of the palms trees, which have been disposed of by burning it. Charcoal Waste Particles of Palm Fronds Base have been used for epoxy matrix as a naturalistic reinforcement particulate material, risk-free, and non-toxic to enhance its features. The charcoal waste particles have been used in weight rates of 0, 2.5, 5, 7.5, and 10%. As stated by the results, the reinforcement process by charcoal waste particles increased the tensile strength value from 8.78 MPa to 13.64 MPa, with a 55%, and increased the elastic modulus value from 0.67MPa to 3.63MPa, with a rate 437%. Moreover, additionally, increased the bending strength from 0.1MPa to 0.64MPa, with a 540%, the hardness value increased from 58.87 to 74 (Shore D No) with a rate 26%, as well as the wear rate has been decreased. Thermal conductivity has dropped by 30% from the pure sample’s value of 0.15W/m. °C to 0.11W/m. °C. Concerning the Acoustic insulation’s, the results demonstrate that the specimens decreased the transferred acoustic energy levels from 103.3 to 95.2dB with rate 8%, with regard to the density of the prepared specimens it has been decreased from 1.55g/cm3 to 1.35g/cm3 and the results show that the liquid absorption rates have been decreased for all composite specimens.

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Size-Resolved Characterization of Particles and Fibers Released during Abrasion of Fiber-Reinforced Composite in a Workplace Influenced by Ambient Background Sources

Cited by 10 publications

References 30 publications

Occupational exposure during handling and loading of halloysite nanotubes – A case study of counting nanofibers

Occupational exposure during handling and loading of halloysite nanotubes – A case study of counting nanofibers

Epoxy composite dusts with and without carbon nanotubes cause similar pulmonary responses, but differences in liver histology in mice following pulmonary deposition

The role of Palm Fronds Charcoal Waste Particles On Mechanical, Thermal, and Acoustic Insulation Properties of Epoxy Composite

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