Hydrogen peroxide toxicity

Safety/Toxicity Carcinogenicity cytotoxicity excitotoxicity hydrogen peroxide toxicity neurotoxicity ... 

Lomonosova, E. E. Kirsch, M. deGroot, H. Calcium vs. iron-mediated processes in hydrogen peroxide toxicity to L929 cells effects of glucose. Free Radical Biol. Med. 1998, 25, 493-503. 

For the experiments biofilm from separately grown Sp and Aa strains was made on polycarbonate membrane. First the Sp biofilm was spread on the membrane and after a spot of the Aa culture was added. In this way a 25 pm diameter bacterial biofilm of Sg with a spot of 5-7 pm Aa in the middle was obtained as substrate for SECM studies. Two different strains of Aa were used - the Y4 and the Y4-katA -containing an insertion mutant of the catalase-encoding gene katA. It is Aa with higher tolerance to hydrogen peroxide toxicity. 

Bruno-Barcena, J.M., Andrus, J.M., Libby, S.L., et al. (2004). Expression of a heterologous manganese superoxide dismutase gene in intestinal lactobacilli provides protection against hydrogen peroxide toxicity. Appl Environ Microbiol 70, 4702-4710. 

Lovell, M. A. Xie, C. Xiong, S. Markesbery, W. R. Protection against amyloid beta peptide and iron/hydrogen peroxide toxicity by alpha lipoic acid. J. Alzheimers Dis. 2003,5,229-239. 

Toxic or malodorous pollutants can be removed from industrial gas streams by reaction with hydrogen peroxide (174,175). Many Hquid-phase methods have been patented for the removal of NO gases (138,142,174,176—178), sulfur dioxide, reduced sulfur compounds, amines (154,171,172), and phenols (169). Other effluent treatments include the reduction of biological oxygen demand (BOD) and COD, color, odor (142,179,180), and chlorine concentration. 

The toxicity of sodium peroxoborate hexahydrate in solution is equivalent to those of sodium borate and hydrogen peroxide. The LD q (mouse, oral) is 1060 mg/kg (2). Local use of high concentrations in the mouth can cause chemical bums and other problems (25). No TLV has been estabhshed. 

Arsenic Peroxides. Arsenic peroxides have not been isolated however, elemental arsenic, and a great variety of arsenic compounds, have been found to be effective catalysts ia the epoxidation of olefins by aqueous hydrogen peroxide. Transient peroxoarsenic compounds are beheved to be iavolved ia these systems. Compounds that act as effective epoxidation catalysts iaclude arsenic trioxide, arsenic pentoxide, arsenious acid, arsenic acid, arsenic trichloride, arsenic oxychloride, triphenyl arsiae, phenylarsonic acid, and the arsenates of sodium, ammonium, and bismuth (56). To avoid having to dispose of the toxic residues of these reactions, the arsenic can be immobi1i2ed on a polystyrene resia (57). 

One of the important consequences of neuronal stimulation is increased neuronal aerobic metabolism which produces reactive oxygen species (ROS). ROS can oxidize several biomoiecules (carbohydrates, DNA, lipids, and proteins). Thus, even oxygen, which is essential for aerobic life, may be potentially toxic to cells. Addition of one electron to molecular oxygen (O,) generates a free radical [O2)) the superoxide anion. This is converted through activation of an enzyme, superoxide dismurase, to hydrogen peroxide (H-iO,), which is, in turn, the source of the hydroxyl radical (OH). Usually catalase... 

Because osmium tetroxide is expensive, and its vapors are toxic, alternate methods have been explored for effecting vic-glycol formation. In the aliphatic series, olefins can be hydroxylated with hydrogen peroxide with the use of only a catalytic amount of osmium tetroxide. Anhydrous conditions are not necessary 30% hydrogen peroxide in acetone or acetone-ether is satisfactory. The intermediate osmate ester is presumably cleaved by peroxide to the glycol with regeneration of osmium tetroxide. When this reaction was tried on a A -steroid, the product isolated was the 20-ketone ... 

In this reaction, hydrogen peroxide is produced which is toxic to cells and has to be removed quickly and efficiently. This is carried out by the enzyme catalase. The C°wrafion equation also indicates the need for molecular oxygen and the fermentation process needs a continuous supply of air. 

Caution Selenium compounds are exceedingly toxic (Note 1). Hydrogen peroxide attacks the skin and may decompose violently (Note 2). The reaction should be carried out behind a safety screen and in an efficient fume hood, and the operator should wear safety glasses and rubber gloves. 

Reduced flavoproteins and complex III may undergo side reactions directly with dioxygen, to a limited extent, forming highly reactive and toxic products, hydrogen peroxide, and superoxide. 

Caution Most selenium compounds are toxic consequently care should be exercised in handling them. The hydrogen peroxide oxidation of selenides is highly exothermic, acid-catalyzed, and auto-catalytic. The procedure given for adding the hydrogen peroxide solution should be carefully followed. 

The chemistry, and hence hazards, of hot, or radioactive, elements parallels that of their cold isotopes. However, the radiation poses additional toxicity hazards. A qualitative classification of selected isotopes in terms of their toxicity is given in Table 10.2. The biological effects of ionizing radiation stem mainly from damage to individual cells following ionization of the water content. Oxidizing species, e.g. hydrogen peroxide. 

It participates in the decomposition of potentially toxic hydrogen peroxide in the reaction catalyzed by glutathione peroxidase (Ghapter 20). 

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