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Trimethylbenzenes (Interagency Science Discussion Draft)

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13 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Hemimellitene (1,2,3-trimethylbenzene) in the liver, lung, kidney, and blood, and dimethylbenzoic acid isomers in the liver, lung, kidney and urine of rats after single and repeated inhalation exposure to hemimellitene

Authors: Świercz, R; Majcherek, W; Wąsowicz, W (2016) International Journal of Occupational Medicine and Environmental Health 29:113-128. HERO ID: 3044616

[Less] OBJECTIVES: The aim of the study has been to explore hemimellitene distribution in blood, liver, lung . . . [More] OBJECTIVES: The aim of the study has been to explore hemimellitene distribution in blood, liver, lung and kidney as well as toxicokinetics of its elimination from blood of rats after single and repeated inhalation exposure to this compound. Tissue distribution and excretion with urine of 2-dimethylbenzoic acids (2,3-DMBA and 2,6-DMBA) were also evaluated.

MATERIAL AND METHODS: Male outbred IMP:WIST rats were used in the experiment. The animals were exposed to hemimellitene vapors at the nominal concentration of 25 ppm, 100 ppm, and 250 ppm in the dynamic inhalation chambers for 6 h for single exposure purpose and for 4 weeks (6 h/day for 5 day/week) for repeated exposure purposes.

RESULTS: Significantly lower concentrations of hemimellitene were detected in the blood and tissues of animals after repeated inhalation exposure of animals to hemimellitene vapors, which points to reduced retention of the chemical in the lungs of the experimental rats. The trend of hemimellitene elimination from the blood depended solely on exposure intensity, irrespective of exposure time, both after single and repeated exposure. As regards the 2 determined hemimellitene metabolites, the major trend of the metabolic transformation involved formation of 2,3-DMBA.

CONCLUSIONS: The significantly higher urinary 2,3-DMBA concentration after repeated exposure shows that hemimellitene induces enzymatic processes in the rat.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Effects and mechanisms of kerosene use-related toxicity

Authors: Maiyoh, GK; Njoroge, RW; Tuei, VC (2015) Environmental Toxicology and Pharmacology 40:57-70. HERO ID: 3044711

[Less] Kerosene is a heterogeneous hydrocarbon substance that continues to find many uses worldwide due to . . . [More] Kerosene is a heterogeneous hydrocarbon substance that continues to find many uses worldwide due to its economic viability and ease of availability. In spite of kerosene's many uses, it is known to cause harm to various body organs and systems. Major affected body organs/systems are the pulmonary system, central nervous system, cardiovascular system, the skin, immune system and liver. This review discusses the various kerosene-mediated adverse health effects and possible mechanisms by which kerosene is likely to inflict such effects. These mechanisms are quite varied and include induction of inflammation, loss of effectiveness of pulmonary surfactants, hypoxia, production of highly reactive oxidative metabolites, extraction of endogenous epidermal and membrane lipids, necrosis, hormonal and enzymatic levels changes, and immunosuppression. Understanding of the above will allow for proper relevant policy formulation and targeted kerosene-mediated morbidity and mortality preventive and management initiatives.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Microbial degradation of gasoline in soil: Effect of season of sampling

Authors: Turner, DA; Pichtel, J; Rodenas, Y; Mckillip, J; Goodpaster, JV (2015) Forensic Science International 251:69-76. HERO ID: 2857167

[Less] In cases where fire debris contains soil, microorganisms can rapidly and irreversibly alter the chemical . . . [More] In cases where fire debris contains soil, microorganisms can rapidly and irreversibly alter the chemical composition of any ignitable liquid residue that may be present. In this study, differences in microbial degradation due to the season in which the sample is collected was examined. Soil samples were collected from the same site during Fall, Winter, Spring and Summer and the degradation of gasoline was monitored over 30 days. Predominant viable bacterial populations enumerated using real-time PCR and reverse transcriptase polymerase chain reaction (RT-PCR) enumeration revealed the predominant viable bacterial genera to be Alcaligenes, Bacillus, and Flavobacterium. Overall, the compounds most vulnerable to microbial degradation are the n-alkanes, followed by the mono-substituted alkylbenzenes (e.g., toluene, ethylbenzene, propylbenzene and isopropylbenzene). Benzaldehyde (a degradation product of toluene) was also identified as a marker for the extent of biodegradation. Ultimately, it was determined that soil collected during an unusually hot and dry summer exhibited the least degradation with little to no change in gasoline for up to 4 days, readily detectable n-alkanes for up to 7 days and relatively high levels of resilient compounds such as o-xylene, p-xylene and 1,3,5-trimethylbenzene. These results demonstrate, however, that prompt preservation and/or analysis of soil evidence is required in order to properly classify an ignitable liquid residue.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Dermal uptake of petroleum substances

Authors: Jakasa, I; Kezic, S; Boogaard, PJ (2015) HERO ID: 2895903

[Less] Petroleum products are complex substances comprising varying amounts of linear and branched alkanes, . . . [More] Petroleum products are complex substances comprising varying amounts of linear and branched alkanes, alkenes, cycloalkanes, and aromatics which may penetrate the skin at different rates. For proper interpretation of toxic hazard data, understanding their percutaneous absorption is of paramount importance.

The extent and significance of dermal absorption of eight petroleum substances, representing different classes of hydrocarbons, was evaluated. Literature data on the steady-state flux and permeability coefficient of these substances were evaluated and compared to those predicted by mathematical models.

Reported results spanned over 5-6 orders of magnitude and were largely dependent on experimental conditions in particular on the type of the vehicle used. In general, aromatic hydrocarbons showed higher dermal absorption than more lipophilic aliphatics with similar molecular weight. The results showed high variation and were largely influenced by experimental conditions emphasizing the need of performing the experiments under "in use" scenario. The predictive models overestimated experimental absorption. The overall conclusion is that, based on the observed percutaneous penetration data, dermal exposure to petroleum hydrocarbons, even of aromatics with highest dermal absorption is limited and highly unlikely to be associated with health risks under real use scenarios. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Characterization of the toxicological hazards of hydrocarbon solvents

Authors: Mckee, RH; Adenuga, MD; Carrillo, JC (2015) Critical Reviews in Toxicology 45:273-365. [Review] HERO ID: 2907800

[Less] Hydrocarbon solvents are liquid hydrocarbon fractions derived from petroleum processing streams, containing . . . [More] Hydrocarbon solvents are liquid hydrocarbon fractions derived from petroleum processing streams, containing only carbon and hydrogen atoms, with carbon numbers ranging from approximately C5-C20 and boiling between approximately 35-370 degrees C. Many of the hydrocarbon solvents have complex and variable compositions with constituents of 4 types, alkanes (normal paraffins, isoparaffins, and cycloparaffins) and aromatics (primarily alkylated one-and two-ring species). Because of the compositional complexity, hydrocarbon solvents are now identified by a nomenclature ("the naming convention") that describes them in terms of physical/chemical properties and compositional elements. Despite the compositional complexity, most hydrocarbon solvent constituents have similar toxicological properties, and the overall toxicological hazards can be characterized in generic terms. To facilitate hazard characterization, the solvents were divided into 9 groups (categories) of substances with similar physical and chemical properties. Hydrocarbon solvents can cause chemical pneumonitis if aspirated into the lung, and those that are volatile can cause acute CNS effects and/or ocular and respiratory irritation at exposure levels exceeding occupational recommendations. Otherwise, there are few toxicologically important effects. The exceptions, n-hexane and naphthalene, have unique toxicological properties, and those solvents containing constituents for which classification is required under the Globally Harmonized System (GHS) are differentiated by the substance names. Toxicological information from studies of representative substances was used to fulfill REACH registration requirements and to satisfy the needs of the OECD High Production Volume (HPV) initiative. As shown in the examples provided, the hazard characterization data can be used for hazard classification and for occupational exposure limit recommendations.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The sub-chronic toxicity of regular White Spirit in rats

Authors: Carrillo, J-C; Adenuga, MD; Mckee, RH (2014) Regulatory Toxicology and Pharmacology 70:222-230. HERO ID: 2897466

[Less] Hydrocarbon solvents are mostly complex substances (UVCB) with carbon numbers in the range of approximately . . . [More] Hydrocarbon solvents are mostly complex substances (UVCB) with carbon numbers in the range of approximately C5-C20. One of the most common types is a C9-C14 aliphatic solvent containing approximately 20% aromatics and commonly known as White Spirit in Europe and mineral spirits in the US. In previous repeated inhalation toxicity studies, White Spirit was reported to cause minimal systemic effects in most animal species with few effects other than male rat-specific kidney changes at levels up to approximately 2000mg/m(3). In the present study male and female rats were exposed to White Spirit vapors, 6h/day, 5days/week for 13weeks at levels of approximately 2000, 4000, or 8000mg/m(3) to assess the potential for effects at higher exposure levels. All of the rats survived the treatment period. In life observations were largely restricted to acute central nervous system (CNS) effects in the high exposure group. Terminal body weights of high exposure groups animals were significantly below control values. Statistically significant differences in the clinical and hematological observations were small and within normal physiological limits. Weights of some organs including liver, spleen and kidneys were elevated, but microscopic examination indicated that the only pathological effects were changes in the kidneys of the male rats, consistent with an α2u-globulin-mediated process, which is gender and species-specific and not relevant to humans. The overall no observed adverse effect level (NOAEC) was 4000mg/m(3).

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Neurobehavioral performance in volunteers after inhalation of white spirits with high and low aromatic content

Authors: Juran, SA; Johanson, G; Ernstgård, L; Iregren, A; van Thriel, C (2014) Archives of Toxicology 88:1127-1140. HERO ID: 3044623

[Less] The content of aromatic hydrocarbons in solvent mixtures, such as white spirits (WS), has been assumed . . . [More] The content of aromatic hydrocarbons in solvent mixtures, such as white spirits (WS), has been assumed a major contributor to the neurotoxic effects of these compounds. Hence, dearomatized WS have been introduced to the market rapidly in the last decade. Studies investigating other aromatic hydrocarbons (toluene) and animal models have supported the aforementioned assumption, but the current study is the first one to compare acute neurobehavioral effects of exposure to aromatic and dearomatized WS (aWS, daWS) content in human volunteers at current occupational exposure limit values. In a pseudo-randomized crossover design, six female and six male healthy volunteers were exposed to aWS and daWS at two concentrations (100 and 300 mg/m(3)) and to clean air for 4 h at rest. During each of the five exposure conditions, volunteers performed five neurobehavioral tasks that were selected following a multidisciplinary approach that accounted for findings from the cognitive neurosciences and mechanisms of solvent toxicity. Two of the tasks indicated performance changes during aromatic WS exposure, the working memory (WM) and the response shifting task, but both effects are difficult to interpret due to low mean accuracy in the WM task and due to a lack of dose-response relationship in the response shifting task. Healthy human volunteers showed weak and inconsistent neurobehavioral impairment after 4-h exposures to 100 and 300 mg/m(3) aromatic or dearomatized WS. Our multidisciplinary approach of selecting neurobehavioral test methods may guide the test selection strategies in future studies.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Characterization of the noncancer hazards of gas oils

Authors: Mckee, RH; Schreiner, CA; White, R; Saperstein, M; Charlap, JH; O'Neill, TP; Goyak, KO; Nicolich, M (2014) International Journal of Toxicology 33:78S-94S. HERO ID: 2816716

[Less] Gas oils, used to manufacture diesel fuel and residential heating oil, are complex hydrocarbon substances . . . [More] Gas oils, used to manufacture diesel fuel and residential heating oil, are complex hydrocarbon substances with carbon numbers of C9-C30 and boiling ranges of approximately 150 °C to 450 °C. Target organ (liver enlargement, reduced thymus weights, and reductions in hematological parameters) and developmental (reduced fetal viability, increased resorption frequency, and reduced fetal weights) effects are associated with aromatic constituents present in some gas oils. Two types of gas oils were tested for repeated-dose and developmental toxicity following repeated dermal administration. A blend of commercial diesel fuels containing 26% aromatics, primarily single-ring compounds, did not cause either target organ or developmental effects at levels up to 600 mg/kg/d. "Cracked" gas oils containing higher levels of aromatic constituents were also tested. Because of limited sample availability, 2 cracked gas oil samples were tested, one for systemic effects and the other for developmental toxicity. The sample tested in the repeated-dose toxicity study (81% aromatics including approximately 10% 3-ring compounds) produced increased liver weights, reduced thymus weights, and reductions in hematological parameters. The overall no observed adverse effect level (NOAEL) was 100 mg/kg/d. The sample tested for developmental toxicity (65% aromatics including approximately 5% 3-ring compounds) resulted in significant reductions in fetal survival, significant increases in resorption frequency, and significant reductions in fetal weights with an overall NOAEL of 100 mg/kg/d. In summary, gas oils may or may not cause target organ and/or developmental effects depending on the levels and types of aromatic constituents that they contain.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The sub-chronic oral toxicity of 1,3,5-trimethylbenzene in Sprague-Dawley rats

Authors: Adenuga, D; Carrillo, JC; Mckee, RH (2014) Regulatory Toxicology and Pharmacology 69:143-153. HERO ID: 2899217

[Less] The systemic toxicity of a trimethylbenzene isomer and constituent of C9 aromatic solvents (1,3,5-trimethylbenzene, . . . [More] The systemic toxicity of a trimethylbenzene isomer and constituent of C9 aromatic solvents (1,3,5-trimethylbenzene, 135-TMB) was studied in Sprague-Dawley rats following a 90-day oral gavage exposure to 0, 50, 200 and 600 mg/kg/day. No statistically significant effects on body weight, body weight gain or food consumption were observed at study termination. Treatment-related changes in clinical chemistry parameters at the end of the 90-day dosing period were limited to small, but statistically significant, increases in phosphorus levels in high dose males and females. Liver enlargement in high dose male/female rats was considered an adaptive response as this was reversible and was not associated with histopathological lesions or increased liver enzyme markers indicative of liver damage. Kidney weight changes were limited to a small, but statistically significant, increase in relative weights in high dose males. This was not associated with histopathological lesions and thus not considered toxicologically relevant. Overall, the No-Observed-Adverse-Effect-Level (NOAEL) was the highest concentration tested (600 mg/kg/day). The results of the present study are relevant for assessing the risk of trimethylbenzenes through the oral route of exposure and provide a basis for the development of provisional screening values for trimethylbenzene isomers while avoiding the uncertainty associated with route-to-route extrapolation.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

[Occupational exposure to airborne chemical substances in paintings conservators]

Authors: Jezewska, A; Szewczyńska, M; Woźnica, A (2014) Medycyna Pracy 65:33-41. HERO ID: 2539080

[Less] BACKGROUND: This paper presents the results of the quantitative study of the airborne . . . [More] BACKGROUND: This paper presents the results of the quantitative study of the airborne chemical substances detected in the conservator's work environment.

MATERIAL AND METHODS: The quantitative tests were carried out in 6 museum easel paintings conservation studios. The air test samples were taken at various stages of restoration works, such as cleaning, doubling, impregnation, varnishing, retouching, just to name a few. The chemical substances in the sampled air were measured by the GC-FID (gas chromatography with flame ionization detector) test method.

RESULTS: The study results demonstrated that concentrations of airborne substances, e.g., toluene, 1,4-dioxane, turpentine and white spirit in the work environment of paintings conservators exceeded the values allowed by hygiene standards. It was found that exposure levels to the same chemical agents, released during similar activities, varied for different paintings conservation studios. It is likely that this discrepancy resulted from the indoor air exchange system for a given studio (e.g. type of ventilation and its efficiency), the size of the object under maintenance, and also from the methodology and protection used by individual employees.

CONCLUSIONS: The levels of organic solvent vapors, present in the workplace air in the course of painting conservation, were found to be well above the occupational exposure limits, thus posing a threat to the worker's health.