Solvent estimated dose

A number of cases of fatal or near-fatal exposure to carbon tetrachloride have been reported following its use as a dry shampoo or as a solvent for removal of adhesives from skin (Chandler 1936 Hardin 1954). However, these cases almost certainly involved high levels of inhalation exposure as well as dermal exposure, and no quantitative estimate of a lethal dermal dose in humans was located. 

The oral LDso of isophorone was reported as 3450 mg/kg in male rats (Hazleton Labs 1964) and 2104-2150 mg/kg in female rats (Smyth et al. 1969, 1970). LDso values of 2700 200 mg/kg for male rats, 2100 200 mg/kg for female rats, and 2200 200 mg/kg for male mice also were reported by Dutertre-Catella (1976). The value reported by Hazleton Labs (1964) was estimated because the mortality data did not lend itself to statistical analysis. Furthermore, the doses were widely spaced, and the animals were fasted for only 3-4 hours before dosing, which could have interfered with gastrointestinal absorption of isophorone. Necropsy of rats that died revealed congestion of the lungs, kidneys, adrenals, and pancreas, and gastrointestinal inflammation. Necropsy of rats that survived the 14-day observation period revealed no effects. The studies by Smyth et al. (1969, 1970) were determinations of the joint toxic action of 27 pairs of industrial solvents (see Section 2.7 on Interactions with other chemicals), but the details of the individual LDs° determinations and the cause of death were not provided. Nevertheless, the values for isophorone were reproducible in the two studies by Smyth et al. (1969, 1970). The reason for the sex difference... 

The solvent was loaded with 137Cs and subsamples were stored on a shaker table while in contact with the extract, scrub, or strip aqueous phases. Evidence of solvent degradation was evaluated for exposure times of 83 days this resulted in estimated solvent doses of 1.24 Mrad, equivalent to the dose expected to be received during 16.5 years of operation at the SRS plant. 

Figure 8. Estimated mean dose to the HDEHP solvent in the CTH process as a function of fuel cooling time...

IPC proved valnable for estimating peptide hydrophobicity [13]. Pharmaceutical science utilized IPC to monitor rat serum esterase activities [14] and also to analyze relationship between plasma concentrations at the end of infusion and toxicity profiles of fixed-dose-rate gemcitabine plus carboplatin [15]. An IPC trap was also used in an online desalting-mass spectrometry system. This system allows ionic compounds in a nonvolatile buffer to be introduced into a MS for strutural elucidation. The trap column was equilibrated with a volatile IPR, the target analyte and the nonvolatile buffer ions (phosphate and sodium ions) were transferred into the trap column, but only the target analyte that interacts with the volative IPR can be retained phospahte buffer ion were eluted from the trap column and the target analyte was eluted by oragnic solvent in a backflush mode and introduced into the MS. 

Toxicity. The estimated minimum lethal dose is 30 g but a single oral dose of 10 mg/kg may produce toxic symptoms the maximum permissible atmospheric concentration is 1 mg/m and the maximum acceptable daily intake is 5 pg/kg. The toxicity of some of the organic solvents, such as kerosene, used in the application of dicophane has probably contributed to dicophane fatalities. 

Men who were exposed to a mist of a specific type of Finnish white spirits used for washing cars (Pfaffli et al. 1985) had elevated levels of dimethylbenzoic acid, a metabolite of trimethylbenzene, in their urine following the workshift. This study attempted to quantify exposure to white spirits through the analysis of dimethylbenzoic acid isomers, which are easily detected markers. It assumed that being in a mixture does not affect the metabolism of trimethylbenzene or any of the other constituents of Stoddard solvent. The amount excreted was linearly related to the estimated exposure level. The composition of the white spirits in this study included 11% aromatics with 1% trimethylbenzene isomers, which is similar to the compositions of Stoddard solvent used in the United States. A correlation between exposure to 1,2,4-trimethylbenzene, a component of white spirits, at the TLV- TWA (25 ppm), and the urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA) was reported in ceramics workers (Fukaya et al. 1994). Rats were dosed by gavage with t-butylcyclohexane (800 mg/kg), another component of white spirits, and seven compounds were identified as urinary metabolites (Flenningsen et al. 1987). The primary metabolite was trans-4-t-butylcyclohexanol, with lesser amounts of 2 "-hydroxy-4t-butylcyclohexanol, 2-methyl-2-cyclohexylpropanoic acid, 2 "-hydroxy- 4 "-t-butylcyclohexanol, 2-methyl-2-cyclohexy 1-1,3-propanediol, 2-hydroxy-4-butylcyclohexanol, and Cis-4-t- butylcyclohexanol also being detected. Rats that had a white spirit formulation (690.8 mg/kg) applied to their tails 5 days/week for 6 weeks were reported to have excreted several products (dimethylbenzoic acid isomers) of trimethylbenzene metabolism in their urine. 

Meta-analysis can be a key element for improving individual research efforts and their reporting in the literature. This is particularly important with regard to an estimate of dose in occupational studies as better reporting of the quantification of solvent exposure is needed in the reproductive toxicology literature. 

The smell of solvent on the breath is related to the dose and duration of exposure and may last for many hours. The so-called glue-sniffer s rash (perioral eczema) is probably caused by repeated contact with glue in a plastic or other bag held to the face. Although primarily a phenomenon of adolescence, it must be remembered that adults, especially those with ready occupational access to abusable volatiles, may also indulge in VSA. In the late 1970s, for example, it was estimated that some 1-1.6% of US dentists were abusing nitrous oxide. 

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