Toxicity benzoic acids

Health aspects, acute toxicity. Benzoic acid is absorbed in the human body from the intestine and metabolised through enzymes to hippuric acid (benzoyl glycocoll), which is excreted in the urine. Additionally relatively small quantities of benzoic acid are linked to glucuronic acid and excreted in the urine by this route. Pollution arising from cooking fumes of food preserved with benzoic acid is under discussion (Benfenati, et al., 1998). 

Your company receives toluene, a listed toxic chemical, from another facility, reacts the toluene with air to form benzoic acid, and further reacts the benzoic acid with a cadmium catalyst to form terephthallc acid. Cadmium compounds and terephthallc acid are also listed toxic chemicals. Your company processes toluene, and otherwise uses (not processes) the cadmium catalyst (see the definition of "otherwise use" below). Your company manufactures benzoic acid and terephthallc acid. Benzoic acid, however, is not a listed chemical and thus does not trigger reporting requirements. 

Yourfacility receives toluene and naphthalene (both listed toxic chemicals) from an off-site location. You react the toluene with air to form benzoic acid and react the naphthalene with sulfuric acid, which forms phthalic acid and also produces sulfur dioxide fumes. Your facility processes toluene and naphthalene. Both are used as reactants to produce benzoic acid and phthalic acid, chemicals not on the section 313 list. 

Phenol was the first commercial antiseptic its introduction into hospitals in the 1870s led to a dramatic decrease in deaths from postoperative infections. Its use for this purpose has long since been abandoned because phenol burns exposed tissue, but many modern antiseptics are phenol derivatives. Toluene has largely replaced benzene as a solvent because it is much less toxic. Oxidation of toluene in the body gives benzoic acid, which is readily eliminated and has none of the toxic properties of the oxidation products of benzene. Indeed, benzoic acid or its sodium salt (Na+, C6H5COO ions) is widely used as a preservative in foods and beverages, including fruit juices and soft drinks. 

Toxicity. Peroxy benzoic acid is moderately toxic but does not cause death or permanent injury (Ref 8)... 

Cyanogenic glycosides toygdalin (or its reduced form, prunasin) and dhurrin are known to be allelopathic (3,48). Not only are these glycosides hydrolyzed to produce hydrogen cyanide, but the benzaldehyde or hydroxybenzaldehyde (produced during hydrolysis) is oxidized to benzoic acid which itself nay be toxic to several species (3, 48). 

Few studies have been conducted to determine organic residues in spent foundry sand and leachates from disposal sites. It is reported that several organic compounds are present in the spent foundry sand but have concentrations below the regulated toxicity characteristic limits. Organic compounds of concern include benzoic acid, naphthalene, methylnaphthalenes, phenol, methylenebisphenol, diethylphenol, and 3-methylbutanoic acids.12 These compounds are thought to be derived from the decomposition of organic binders such as phenolic urethane, furan, and alkyd isocyanate. 

Phenolic acids can be allelopathic but their presence in soil is ephemeral due to rapid degradation and/or sorption by soil particles (Inderjit 2004). Sorption of benzoic acid onto soil particles increased with concentration and it may explain the reason for the limited allelopathic effect of benzoic acid at concentrations often recorded in natural soil (Inderjit 2004). Microorganisms help to generate allelochemicals, but they may also modify toxic compounds into nontoxic compounds (Khanh et al. 2005). Allelochemicals are changed in composition and quantity during the residue decomposition. Allelopathy plays an important function in nutrient recycling (Rice 1984). 

Say you have to separate a mixture of benzoic acid (1), phenol (2), p-tolui-dine (4-Methylanaline) (3), and anisole (methoxybenzene) (4) by extraction. The numbers refer to the class of compound, as previously listed. We re assuming that none of the compounds react with any of the others and that you know we re using all four types as indicated. Phenol and 4-methylanaline are corrosive toxic poisons and if you get near these compounds in lab, be very careful. When they are used as an example on these pages, however, you are quite safe. Here s a sequence of tactics. 

Table 6.3 gives typical data for the metabolism of benzoic acid to its less toxic metabolite hippuric acid. 

Toxicity can occur because, unfortunately, some metabolites are, unlike benzoic acid, more toxic than the chemical that enters the body. Enzymes can cause certain changes in molecular arrangements that introduce groupings of atoms that can interact with components of cells in highly damaging ways. The industrial chemical bromobenzene can be converted in the liver to a metabolite called bromobenzene epoxide, as depicted in the diagram. 

Muccini, M., Layton, A.C., Sayler, G.S., and Schultz, T.W. Aquatic toxicities of halogenated benzoic acids to Tetrahymena pyriformis, Bull. Environ. Contam. Toxicol, 62(5) 616-622, 1999. 

The biosynthesis of sulfate esters with the help of phosphoadenosine phosphosulfate (PAPS), the active sulfate , (see p. 110) and amide formation with glycine and glutamine also play a role in conjugation. For example, benzoic acid is conjugated with glycine to form the more soluble and less toxic hippuric acid (N-benzoylglycine see p. 324). 

Benzoic acid with salicylic acid is useful as an antifungal agent against various types of dermatophy-toses. The combination also has keratolytic properties. Salicylic acid may cause mild irritation of the skin. If applied to large areas of the body, amounts sufficient to cause toxicity may be absorbed. 

Jasminum samba (L.) Aiton Mo Li Hua (Arabian jasmine) (flower, root) Formic acid, benzoic acid, acetic acid, anthranil acid, sesquiterpene, sesquijasmine.60 This herb (root) is toxic. Sedative, anesthetic, vulnerary properties. For congestive headache, lactifuge. 

Arisaema consanguineum Mart. China Alkaloids, saponin, benzoic acid.33-49 This herb is highly toxic. Treat tetanus, spasms, epilepsy, neuralgia. Sedative, anticonvulsive, an expectorant. 

To circumvent this bioactivation pathway, a more easily oxidizable C-H bond can be included in the molecule, such as a benzylic methyl group. Thus, toluene, is significantly less toxic than benzene since its major CYP metabolite is benzyl alcohol, which is converted to benzoic acid by ALDH. Benzoic acid is conjugated with glycine and eliminated in the urine as hippuric acid, which is much less toxic than the metabolites of benzene... 

Besides local toxicity, discussed above, there are numerous other modes of potential adverse interactions involving excipients (19,20). Many of these pose little threat provided the amounts of excipients are constrained to certain levels. Excessive amounts, however, can cause problems, particularly for patients who are intolerant of even modest levels. Commonly used phosphate buffers may cause calcium loss with formation of insoluble calcium phosphates when such buffers are administered in over-ambitious amounts (21). Calcium phosphate precipitation has been noted particularly in nutritional parenteral admixtures for neonates because of the high nutrient requirements. Similarly, renal toxicity has been associated with depletion of zinc and other trace metals caused by large parenteral doses of ethylenediaminete-traacetic acid (EDTA) (22). Excessive absorption of glycine solutions, when used as irrigants during transurethral resections, can cause hyponatremia, hypertension, and confusion (23). The use of preservatives has been associated with cardiac effects in a few patients (24). Premature neonates were found to be at risk for receiving toxic amounts of benzoic acid or benzyl alcohol in bacteriostatic solutions used to flush intravenous catheters (25). 

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