INHALATION TOXICITY OF 1,6-HEXAMETHYLENE DIISOCYANATE HOMOPOLYMERS (HDI-IC AND HDI-BT): Results of Subacute and Subchronic Repeated Inhalation Exposure Studies

Effect of 1,6-Hexamethylene Diisocyanate Exposure on Peak Flowmetry in Automobile Paint Shop Workers in IranThe aim of this study was to investigate the effects of occupational exposure to 1,6-hexamethylene diisocyanate (HDI) on peak flowmetry in automobile body paint shop workers in Iran. We studied a population of 43 car painters exposed to HDI at their workplaces. Peak expiratory flow was tested for one working week, from the start to the end of each shift. Air was sampled and HDI analysed in parallel, according to the OSHA 42 method.Daily and weekly HDI exposure averages were (0.42±0.1) mg m-3 and (0.13±0.05) mg m-3, respectively.On painting days, 72 % of workers showed more than a 10 % variation in peak expiratory flow. Inhalation exposure exceeded the threshold limit value (TLV) ten times over. This strongly suggests that HDI affected the peak flowmetry in the studied workers.

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Effect of electric heating and ice added to the bowl on mainstream waterpipe semivolatile furan and other toxicant yields

Tobacco Control ◽

10.1136/tobaccocontrol-2019-054961 ◽

2019 ◽

Vol 29 (Suppl 2) ◽

pp. s110-s116 ◽

Cited By ~ 4

Author(s):

Marielle C Brinkman ◽

Andreas A Teferra ◽

Noura O Kassem ◽

Nada OF Kassem

Keyword(s):

Inhalation Exposure ◽

Electric Heating ◽

Inhalation Toxicity ◽

Toxicity Data ◽

Total Particulate Matter ◽

Mutagenic Potential ◽

Waterpipe Tobacco Smoking ◽

Educational Campaigns ◽

Ice Water ◽

Smoking Behaviours

ObjectivesWe examined mainstream total particulate matter, nicotine, cotinine, menthol, pyrene, carbon monoxide (CO) and semivolatile furan yields from a commercial waterpipe with two methods for heating the tobacco, quick-light charcoal (charcoal) and electric head (electric) and two water bowl preparations: with (ice) and without ice (water).MethodsEmissions from a single brand of popular waterpipe tobacco (10 g) were generated using machine smoking according to a two-stage puffing regimen developed from human puffing topography. Tobacco and charcoal consumption were calculated for each machine smoking session as mass lost, expressed as a fraction of presmoking mass.ResultsThe heating method had the greatest effect on toxicant yields. Electric heating resulted in increases in the fraction of tobacco consumed (2.4 times more, p<0.0001), mainstream nicotine (1.4 times higher, p=0.002) and semivolatile furan yields (1.4 times higher, p<0.03), and a decrease in mainstream CO and pyrene yields (8.2 and 2.1 times lower, respectively, p<0.001) as compared with charcoal. Adding ice to the bowl resulted in higher furan yields for electric heating. Menthol yields were not different across the four conditions and averaged 0.16±0.03 mg/session. 2-Furaldehyde and 5-(hydroxymethyl)−2-furaldehyde yields were up to 230 and 3900 times higher, respectively, than those reported for cigarettes.ConclusionWaterpipe components used to heat the tobacco and water bowl preparation can significantly affect mainstream toxicant yields. Mainstream waterpipe tobacco smoke is a significant source of inhalation exposure to semivolatile furans with human carcinogenic and mutagenic potential. These data highlight the need for acute and chronic inhalation toxicity data for semivolatile furans and provide support for the establishment of limits governing sugar additives in waterpipe tobacco and educational campaigns linking waterpipe tobacco smoking behaviours with their associated harm.

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Subacute Inhalation Exposure of Rats to 1,6-Hexamethylene Diisocyanate With Recovery Period

Inhalation Toxicology ◽

10.1080/08958370600742730 ◽

2006 ◽

Vol 18 (9) ◽

pp. 659-665 ◽

Cited By ~ 4

Author(s):

Ronald N. Shiotsuka ◽

Barry P. Stuart ◽

Ghona K. Sangha ◽

David W. Sturdivant ◽

Herbert Hoss

Keyword(s):

Recovery Period ◽

Inhalation Exposure ◽

Hexamethylene Diisocyanate

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Epigenetic Markers Are Associated With Differences in Isocyanate Biomarker Levels in Exposed Spray-Painters

Frontiers in Genetics ◽

10.3389/fgene.2021.700636 ◽

2021 ◽

Vol 12 ◽

Author(s):

Laura W. Taylor ◽

John E. French ◽

Zachary G. Robbins ◽

Leena A. Nylander-French

Keyword(s):

Smoking Status ◽

Cpg Islands ◽

Inhalation Exposure ◽

Mitigation Strategies ◽

Hexamethylene Diisocyanate ◽

Future Research ◽

Epigenetic Markers ◽

Skin Exposure ◽

Protein Functions ◽

Apoptosis Regulation

Isocyanates are respiratory and skin sensitizers that are one of the main causes of occupational asthma globally. Genetic and epigenetic markers are associated with isocyanate-induced asthma and, before asthma develops, we have shown that genetic polymorphisms are associated with variation in plasma and urine biomarker levels in exposed workers. Inter-individual epigenetic variance may also have a significant role in the observed biomarker variability following isocyanate exposure. Therefore, we determined the percent methylation for CpG islands from DNA extracted from mononuclear blood cells of 24 male spray-painters exposed to 1,6-hexamethylene diisocyanate (HDI) monomer and HDI isocyanurate. Spray-painters’ personal inhalation and skin exposure to these compounds and the respective biomarker levels of 1,6-diaminohexane (HDA) and trisaminohexyl isocyanurate (TAHI) in their plasma and urine were measured during three repeated industrial hygiene monitoring visits. We controlled for inhalation exposure, skin exposure, age, smoking status, and ethnicity as covariates and performed an epigenome-wide association study (EWAS) using likelihood-ratio statistical modeling. We identified 38 CpG markers associated with differences in isocyanate biomarker levels (Bonferroni < 0.05). Annotations for these markers included 18 genes: ALG1, ANKRD11, C16orf89, CHD7, COL27A, FUZ, FZD9, HMGN1, KRT6A, LEPR, MAPK10, MED25, NOSIP, PKD1, SNX19, UNC13A, UROS, and ZFHX3. We explored the functions of the genes that have been published in the literature and used GeneMANIA to investigate gene ontologies and predicted protein-interaction networks. The protein functions of the predicted networks include keratinocyte migration, cell–cell adhesions, calcium transport, neurotransmitter release, nitric oxide production, and apoptosis regulation. Many of the protein pathway functions overlap with previous findings on genetic markers associated with variability both in isocyanate biomarker levels and asthma susceptibility, which suggests there are overlapping protein pathways that contribute to both isocyanate toxicokinetics and toxicodynamics. These predicted protein networks can inform future research on the mechanism of allergic airway sensitization by isocyanates and aid in the development of mitigation strategies to better protect worker health.

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The Acute Toxicity of Tris(Dimethylamino) Silane

Toxicology and Industrial Health ◽

10.1177/074823378900500104 ◽

1989 ◽

Vol 5 (1) ◽

pp. 45-54 ◽

Cited By ~ 3

Author(s):

Bryan Ballantyne ◽

Darol E. Dodd ◽

Roy C. Myers ◽

Donald J. Nachreiner ◽

Irvin M. Pritts

Keyword(s):

Saturated Vapor ◽

Inhalation Exposure ◽

Glass Tube ◽

Female Rats ◽

Male Rat ◽

Inhalation Toxicity ◽

Moist Air ◽

Atmospheric Concentration ◽

Air Intake ◽

Chamber Gas

The acute handling hazards of tris(dimethylamino)silane [TDMAS] were investigated. The acute male rat peroral LD50 (with 95% confidence limits) was 0.71 (0.51-0.97) ml/kg, and the acute male rabbit percutaneous LD 50 was 0.57 (0.35-0.92) ml/ kg. The liquid was severely irritating to the rabbit eye and skin, and the vapor severely irritating to the rat eye. The dynamically generated saturated vapor Lt50 in female rats was 12 (9.7-15) min. The effect of varying the atmospheric concentration of vapor from TDMAS on acute inhalation toxicity was investigated by passing ordinary moist air countercurrent to liquid TDMAS metered into a slightly heated glass tube. Based on nominal concentrations, the 4 hr-LC50 for vapor from TDMAS was 734 (603-893) ppm in female rats by this procedure. Stoichiometrically, this accords with toxicity due to liberation of dimethylamine (DMA)from TDMAS. In a subsequent study designed to assess the influence of relative humidity on vapor toxicity, nitrogen was passed over heated liquid TDMAS and the resultant atmosphere was introduced into the air intake duct of the inhalation exposure chamber. Gas chromatographically measured TDMAS concentrations (± SD) were 395 ± 111, 127 ± 25, 62 ± 8 and 23 ± 21 ppm; the corresponding DMA vapor concentrations were 112 ± 171, 31 ± 43, 10 ± 6 and 26 ± 44 ppm. The 4-hr LC50 (males and females) was 38 (34-43) ppm TDMAS vapor. Thus, TDMAS is of moderate acute peroral and percutaneous toxicity, a severe primary skin and eye irritant, an aspiration hazard, and of high intrinsic acute inhalation toxicity, but in moist air conditions lethal toxicity may be reduced and in such circumstances DMA may be a significant factor in toxicity.

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Nanotechnologies. Characterization of nanoparticles in inhalation exposure chambers for inhalation toxicity testing

10.3403/30190435u ◽

2015 ◽

Keyword(s):

Inhalation Exposure ◽

Toxicity Testing ◽

Inhalation Toxicity

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Acute inhalation toxicity study of n-heneicosane and its combination with diflubenzuron: An attracticide of Aedes aegypti

Toxicology and Industrial Health ◽

10.1177/0748233718774987 ◽

2018 ◽

Vol 34 (10) ◽

pp. 703-713

Author(s):

Anshoo Gautam ◽

Deeksha Singh ◽

Peeyush Shrivastava ◽

R Vijayaraghavan

Keyword(s):

Body Weight ◽

Inhalation Exposure ◽

Insect Growth Regulator ◽

Exposure Chamber ◽

Whole Body ◽

Inhalation Toxicity ◽

Toxicological Evaluation ◽

Pressure Transducers ◽

Mammalian Toxicity ◽

Respiratory Variables

Objective: Combination of an oviposition pheromone and an insect growth regulator for the control of vectors is an effective approach. There is a need for toxicological evaluation before its introduction. The present study evaluates the acute inhalation toxicity of n-heneicosane and its combination with diflubenzuron in a head-only inhalation exposure chamber made of glass. Materials and methods: A head-only inhalation exposure chamber made of glass (volume: 3.5 l) was used for exposing four rats at a time. A glass nebulizer was used for aerosolization of n-heneicosane and its combination with diflubenzuron (1:10 w/w). Nebulization pressure was 10 and 15 psi and the air flow of exposure the chamber was adjusted to 30 lpm. Male Wistar rats were acclimatized in whole body plethysmographs that were connected to volumetric flow pressure transducers by silicon tubes. The transducers were connected to an amplifier and a digitized response was recorded through an oscillograph and personal computers. Respiratory variables were recorded online. After inhalation exposure, various other parameters like survival, body weight, organ body weight index and biochemical changes were recorded for analysis. Results and discussion: Particle size determination proved that the aerosol particles were within the respirable range. LC50 of n-heneicosane and its combination with diflubenzuron was found to be more than 5 g/m3. There were minimal changes observed during exposure to n-heneicosane and also its combination with diflubenzuron on the respiratory variables. The changes were not consistent with the dose. Conclusion: n-Heneicosane and its combination with diflubenzuron showed low mammalian toxicity.

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