scholarly journals Evaluation of an Ozone Chamber as a Routine Method to Decontaminate Firefighters’ PPE

Author(s):  
Marcella A. de Melo Lucena ◽  
Félix Zapata ◽  
Filipe Gabriel M. Mauricio ◽  
Fernando E. Ortega-Ojeda ◽  
M. Gloria Quintanilla-López ◽  
...  

Ozone chambers have emerged as an alternative method to decontaminate firefighters’ Personal Protective Equipment (PPE) from toxic fire residues. This work evaluated the efficiency of using an ozone chamber to clean firefighters’ PPE. This was achieved by studying the degradation of pyrene and 9-methylanthracene polycyclic aromatic hydrocarbons (PAHs). The following experiments were performed: (i) insufflating ozone into PAH solutions (homogeneous setup), and (ii) exposing pieces of PPE impregnated with the PAHs to an ozone atmosphere for up to one hour (heterogeneous setup). The ozonolysis products were assessed by Fourier Transform Infrared Spectroscopy (FTIR), Thin-Layer Chromatography (TLC), and Mass Spectrometry (MS) analysis. In the homogeneous experiments, compounds of a higher molecular weight were produced due to the incorporation of oxygen into the PAH structures. Some of these new compounds included 4-oxapyren-5-one (m/z 220) and phenanthrene-4,5-dicarboxaldehyde (m/z 234) from pyrene; or 9-anthracenecarboxaldehyde (m/z 207) and hydroxy-9,10-anthracenedione (m/z 225) from 9-methylanthracene. In the heterogeneous experiments, a lower oxidation was revealed, since no byproducts were detected using FTIR and TLC, but only using MS. However, in both experiments, significant amounts of the original PAHs were still present even after one hour of ozone treatment. Thus, although some partial chemical degradation was observed, the remaining PAH and the new oxygenated-PAH compounds (equally or more toxic than the initial molecules) alerted us of the risks to firefighters’ health when using an ozone chamber as a unique decontamination method. These results do not prove the ozone-advertised efficiency of the ozone chambers for decontaminating (degrading the toxic combustion residues into innocuous compounds) firefighters’ PPE.

1999 ◽  
Vol 82 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Jean-Louis Gafner

Abstract Classical microbiological methods for determining antimicrobial compounds in feeds are nonspecific. Thus, there is a need to identify biological activity, and bioautography is used for thispurpose. A routine method for detecting the following antimicrobial sub stances in feeds is described: avilamycin, avoparcin, Zn-bacitracin, erythromycin, flavomycin, furazolidone, lasalocid, monensin, narasin, penicillin, salinomycin, spiramycin, tetracyclines, tylosin, and virginiamycin. Carbadox can be detected by UV light examination of the plates prior to bioautography. Semiquantitative estimations of antibiotic content are compared with quantitative determinations of the above mentioned sub stances in feeds, except erythromycin, penicillin, and tetracyclines. Detection limits range from 0.1 mg/kg (chlortetracycline) to 20 mg/kg (lasalocid). The method involves agar diffusion of buffered samples, a neutral extraction of polyether antibiotics followed bythin-layer chromatography (TLC), and an acid extraction for other antibiotics followed by TLC. Five test bacteria were used for the main detection by agar diffusion: Micrococcus luteusATCC 9341, Staphylococcus aureus ATCC 6538P, Corynebacterium xerosis NCTC 9755, Bacillus cereus ATCC 11778, and B. subtilis ATCC 6633. Identification after TLC was achieved by bioautography with the most sensitive microorganism(s). This method allows one laboratory technician to analyze up to 30 feed samples within 2.5 working days, provided that feeds of the same category are analyzed in the same run, and that labels of additives are available. Qualitative and semiquantitative information are valuable when performing a quantitative antibiotic determination and it provides proof that the activity determined is due to the tested substance. This last feature is essential from the perspective of quality assurance of results.


2015 ◽  
Vol 3 (9) ◽  
pp. 1898-1906 ◽  
Author(s):  
Jing Chen ◽  
Yao-wen Huang ◽  
Yiping Zhao

The combinatory use of on-chip ultra-thin layer chromatography (UTLC) and surface enhanced Raman spectroscopy (SERS) has been demonstrated to detect mixtures of hazardous food contaminants, polycyclic aromatic hydrocarbons (PAHs), from cooking oil samples.


In a former communication (Cook, Dodds, Hewett, and Lawson, 1934) we recorded the oestrogenic activity of a number of polycyclic aromatic and hydroaromatic compounds. The most active substances were found among a series of diols related to the carcinogenic hydro­carbon, 1 : 2 : 5 : 6-dibenzanthracene. We have now extended our investi­gation to seven new members of this series and have also examined a variety of diols of analogous structure, but containing other ring systems. Table I summarizes the results obtained in tests for oestrogenic activity carried out with 9: 10-dihydroxy-9: 10-dialkyl-9: 10-dihydro-1: 2: 5: 6- dibenzanthracenes. In none of the new compounds has the activity exceeded that of the most potent compound previously described, namely, the di- n -propyl derivative in this series. Among the straight-chain dialkyl compounds this di- n -propyl compound represents a peak of activity in a series of which the first (methyl) and higher ( n -amyl, n -hexyl) members are inactive. Two branched-chain compounds ( iso -propyl, iso -butyl) are fairly highly active, but show diminished activity by comparison with the corresponding straight-chain isomerides. This is particularly marked for the iso -propyl compound, which is about ten times less active than the n -propyl compound. In view of the high order of activity of the n -propyl compound, it is remarkable that the allyl compound has given negative results when injected into ovariectomized rats in 10 mg. doses.


Sign in / Sign up

Export Citation Format

Share Document