QSAR modelling of inhalation toxicity of diverse volatile organic molecules using no observed adverse effect concentration (NOAEC) as the endpoint

Chemosphere ◽  
2022 ◽  
Vol 287 ◽  
pp. 131954
Author(s):  
Aniket Nath ◽  
Priyanka De ◽  
Kunal Roy
Keyword(s):  
Adverse Effect ◽  
Organic Molecules ◽  
Inhalation Toxicity ◽  
Qsar Modelling ◽  
Volatile Organic ◽  
Effect Concentration

Prediction of No Observed Adverse Effect Concentration for inhalation toxicity using Monte Carlo approach

2020 ◽  
Vol 31 (12) ◽  
pp. 1-12
Author(s):  
A.A. Toropov ◽  
A.P. Toropova ◽  
G. Selvestrel ◽  
D. Baderna ◽  
E. Benfenati
Keyword(s):  
Adverse Effect ◽  
Monte Carlo ◽  
Inhalation Toxicity ◽  
Monte Carlo Approach ◽  
Effect Concentration

A rationally designed vapoluminescent compound with adsorptive channels and responsive luminophores for volatile organic compounds (VOCs)

2019 ◽  
Vol 48 (4) ◽  
pp. 1179-1183 ◽  
Author(s):  
Mingxue Yang ◽  
Xiao-Ning Li ◽  
Ji-Hui Jia ◽  
Xu-Lin Chen ◽  
Can-Zhong Lu
Keyword(s):  
Volatile Organic Compounds ◽  
Solvent Effect ◽  
Organic Compounds ◽  
Organic Molecules ◽  
Volatile Organic ◽  
First Time

We designed a sensor compound which for the first time combines the solvent effect of ICT organic molecules with large channels adsorbing VOCs.

1,1,2,2-Tetrafluoroethane (HFC-134) (2018)

2019 ◽  
Vol 35 (3) ◽  
pp. 196-203
Keyword(s):  
Adverse Effect ◽  
Adverse Effects ◽  
Toxicity Study ◽  
Whole Body ◽  
Exposure Level ◽  
Inhalation Toxicity ◽  
Hfc 134A ◽  
Adverse Effect Level ◽  
Effect Level ◽  
Whole Body Inhalation

1,1,2,2-Tetrafluoroethane (HFC-134) is a colorless gas used as a foam expansion agent and heat transfer fluid. HFC-134 has a low acute inhalation toxicity with an LC50 of >244,000 ppm. The no-observed adverse effect level (NOAEL) and lowest-observed adverse effect level for cardiac sensitization (in epinephrine-challenged beagle dogs) were 75,000 and 100,000 ppm, respectively. A subacute 4-week GLP inhalation toxicity study exposed male and female Crl: CD®BR rats (10/sex) to 0, 2000, 10,000, or 50,000 ppm via whole-body inhalation. Transient and non-dose-response–related body weight changes were observed throughout the exposure period, but no statistically significant, test substance-related adverse effects were observed in any clinical observations, chemistry, hematology, or pathology. This study identified a NOAEL for HFC-134 of 50,000 ppm, the highest exposure level tested. HFC-134 is not genotoxic in in vitro studies; however, no in vivo studies are available. No developmental or maternal toxicity was found in female rats exposed to HFC-134 up to 50,000 ppm via whole-body inhalation in two different studies. Based on data for a similar material (HFC-134a), HFC-134 is not expected to be extensively metabolized or to cause genetic toxicity or carcinogenicity. The HFC-134 workplace environmental exposure level (WEEL) is based primarily on the subacute 4-week inhalation toxicity study in rats with the NOAEL of 50,000 ppm selected as the point of departure for the derivation of the 8-h TWA, health-based WEEL value. The developmental toxicity study also had a NOAEL of 50,000 ppm and was the highest exposure level tested. The subacute inhalation NOAEL was adjusted to account for interindividual variability, subacute to chronic duration, animal to human extrapolation, daily duration of exposure, and residual uncertainty. In addition, the lack of adverse effects noted in the toxicology studies for HFC-134a was considered. The resulting 8-h TWA WEEL value of 1000 ppm is expected to provide a significant margin of safety against the production of any potential adverse health effects in workers following long-term inhalation exposure to HFC-134.

scholarly journals Effect of NO<sub><i>x</i></sub> on 1,3,5-trimethylbenzene (TMB) oxidation product distribution and particle formation

2019 ◽  
Vol 19 (23) ◽  
pp. 15073-15086 ◽  
Author(s):  
Epameinondas Tsiligiannis ◽  
Julia Hammes ◽  
Christian Mark Salvador ◽  
Thomas F. Mentel ◽  
Mattias Hallquist
Keyword(s):  
Urban Areas ◽  
Organic Molecules ◽  
Flow Reactor ◽  
Organic Aerosol ◽  
Product Distribution ◽  
Particle Formation ◽  
Product Distributions ◽  
Tropospheric Aerosol ◽  
Volatile Organic ◽  
Free Environment

Abstract. Secondary organic aerosol (SOA) represents a significant fraction of the tropospheric aerosol and its precursors are volatile organic compounds (VOCs). Anthropogenic VOCs (AVOC) dominate the VOC budget in many urban areas with 1,3,5-trimethylbenzene (TMB) being among the most reactive aromatic AVOCs. TMB formed highly oxygenated organic molecules (HOMs) in an NOx-free environment, which could contribute to new particle formation (NPF) depending on oxidation conditions where elevated OH oxidation enhanced particle formation. The experiments were performed in an oxidation flow reactor, the Go:PAM unit, under controlled OH oxidation conditions. By addition of NOx to the system we investigated the effect of NOx on particle formation and on the product distribution. We show that the formation of HOMs, and especially HOM accretion products, strongly varies with NOx conditions. We observe a suppression of HOM and particle formation with increasing NOx/ΔTMB ratio and an increase in the formation of organonitrates (ONs) mostly at the expense of HOM accretion products. We propose reaction mechanisms and pathways that explain the formation and observed product distributions with respect to oxidation conditions. We hypothesise that, based on our findings from TMB oxidation studies, aromatic AVOCs may not contribute significantly to NPF under typical NOx/AVOC conditions found in urban atmospheres.

Modeling permeation of volatile organic molecules through reverse osmosis spiral-wound membranes

2009 ◽  
Vol 330 (1-2) ◽  
pp. 40-50 ◽  
Author(s):  
Camille Sagne ◽  
Claire Fargues ◽  
Bertrand Broyart ◽  
Marie-Laure Lameloise ◽  
Martine Decloux
Keyword(s):  
Reverse Osmosis ◽  
Organic Molecules ◽  
Volatile Organic ◽  
Spiral Wound

Effect of Pre-Ozonation on Removal of Organic Matter during Water Treatment Plant Operations

1993 ◽  
Vol 27 (11) ◽  
pp. 37-45 ◽  
Author(s):  
Marc Edwards ◽  
Markus Boller ◽  
Mark M. Benjamin
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Organic Molecules ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Turbidity Removal ◽  
Volatile Organic ◽  
Plant Operations ◽  
High Concentrations ◽  
Main Effects

Pre-ozonation altered removal of organic matter during bench or full-scale water treatment through two main effects. First, pre-ozonation directly removed organic matter by mineralization, volatilization and/or stripping reactions, improving removal in comparison to unozonated systems. On the other hand, pre-ozonation decreased the surface charge of floc formed after coagulation with hydrolyzable metal salts, hindering adsorptive removal of the anionic organic molecules by floc surfaces and/or inducing stabilized floc formation; changes that decrease removal in comparison to unozonated systems. The relative importance of the two effects determined whether pre-ozonation enhanced or hindered removal of organic matter. In most water treatment plants pre-ozonation is predicted to have an adverse effect on physical removal of organic matter at ozone doses above about 0.7 mg O3/mg TOC, while enhanced removal may occur if relatively high concentrations of volatile organic matter are present. In ancillary results, pre-ozonation hindered turbidity removal and increased the concentration of coagulant metal residuals in finished drinking water at low coagulant doses.

scholarly journals Highly Oxygenated Organic Molecules Produced by the Oxidation of Benzene and Toluene in a Wide Range of OH Exposure and NO<sub>x</sub> Conditions

2021 ◽  
Author(s):  
Xi Cheng ◽  
Qi Chen ◽  
Yong Jie Li ◽  
Yan Zheng ◽  
Keren Liao ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Product Distribution ◽  
Flow Tube ◽  
Experimental Conditions ◽  
Effective Lifetime ◽  
Wide Range ◽  
Volatile Organic ◽  
Multifunctional Products ◽  
Oxidation Of Benzene ◽  
Oxygenated Products

Abstract. Oxidation of aromatic volatile organic compounds (VOCs) leads to the formation of tropospheric ozone and secondary organic aerosol, for which gaseous oxygenated products are important intermediates. We show herein experimental results of highly oxygenated organic molecules (HOMs) produced by the oxidation of benzene and toluene in a wide range of OH exposure and NOx conditions. The results suggest multi-generation OH oxidation plays an important role in the product distribution, which likely proceeds more preferably via H subtraction than OH addition for early-generation products from light aromatics. Our experimental conditions promote the formation of more oxygenated products than previous flow-tube studies. The formation of dimeric products however was suppressed and might be unfavorable under conditions of high OH exposure and low NOx in toluene oxidation. Under high-NOx conditions, nitrogen-containing multifunctional products are formed, while the formation of other HOMs is suppressed. Products containing two nitrogen atoms become more important as the NOx level increases, and the concentrations of these compounds depend significantly on NO2. The highly oxygenated nitrogen-containing products might be peroxyacylnitrates, implying a prolonged effective lifetime of RO2 that facilitates regional pollution. Our results call for further investigation on the roles of high-NO2 conditions in the oxidation of aromatic VOCs.

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