Malodorants effects

Fatty acids are susceptible to oxidative attack and cleavage of the fatty acid chain. As oxidation proceeds, the shorter-chain fatty acids break off and produce progressively higher levels of malodorous material. This condition is known as rancidity. Another source of rancidity in fatty foods is the enzymatic hydrolysis of the fatty acid from the glycerol. The effect of this reaction on nutritional aspects of foods is poorly understood andhttie research has been done in the area. 

Elevated Flares See Flares for a general definition. The elevated flare, by the use of steam injection and effective tip design, operates as a smokeless combustion device. Flaring generally is of low luminosity up to about 20 % of maximum flaring load. Steam injection tends to introduce a source of noise to the operation, and a compromise between smoke elimination and noise is usually necessary. When adequately elevated (by means of a stack) this type of flare displays the best dispersion characteristics for malodorous and toxic combustion products. Visual and noise pollution often creates nuisance problems. Capital and operating costs tend to be high, and an appreciable plant area can be rendered unavailable for plant operations and equipment because of excessive radiant heat. 

Jaakkola JJ, Vilkka V, Marttila O, et al. 1990. The South Karelia air pollution study. The effects of malodorous sulfur compounds from pulp mill on respiratory and other symptoms. Am Rev Respir Dis 142 1344-1350. 

Partti-Pellinen K, Martilla O, Vilkka V, et al. 1996. The South Karelia air pollution study Effects of low-level exposure to malodorous sulfur compounds on symptoms. Arch Environ Health 51 315-320. 

Malodorants do not seriously endanger life except at exposures greatly exceeding an effective dose, usually only achieved in a confined or enclosed space. 

Some malodorants are insoluble in water and difficult to remove with soap and water. In such situations, an aqueous solution of mild oxidants may be effective in destroying the odorous ingredients of the agent. Published examples include... 

Methods that have an oxidizing effect may also typically reduce malodors. Chemical precipitation, however, is only effective for the control of sulfide problems. 

Finlay, I.G., Bowszyc, J., Ramlau, C. and Gwiezdzinski,Z. (1996) The effect of topical 0.75% metronidazole gel on malodorous cutaneous ulcers. J. Pain Symptom Manag. 11, 158-162. 

In contrast to the relatively limited number of organosulfur compounds in these species, the anal sac secretions of skunks contain large numbers of malodorous compounds, which are very effectively utilized in the defensive behavior of these species. During the early years of capillary gas chromatography, Andersen et al. [108] found that 150 of the 160 components detected in the anal gland secretion of the striped skunk, Mephitis mephitis, contained sulfur. The results of recent chemical studies on North American skunks by Wood et al. [109] are summarized in Table 4. Only three of the compounds reported in this table are common to the secretions of all four skunk species and, in two of these three secretions, the common compound is present in concentrations of about 1% or less. Although it is clear that skunks use their anal gland secretions primarily for defensive purposes, it does not rule out the possibility that the difference in the composition of these secretions could also be utilized for... 

Since more than 10 years much research is done on the anaerobic digestion from slurry. This research is mainly stimulated by the option of the renewable energy biogas. But there is also an effect on the presence of the malodorous compounds. In the next chapter more details are presented. 

The introductory Chapter 2 of the Air Quality Guidelines (WHO 2000) gives a very detailed and comprehensive description of the criteria used in establishing the guideline values including criteria for selection of NOAEL/LOAEL, adverse effect, benchmark approach, and uncertainty factors. These criteria are comparable to the principles outlined in Chapters 4 and 5 in this book. There are also criteria for selection of averaging times and for consideration of sensory effects (malodorous... 

At concentrations below those necessary to produce toxic effects, ethyl mercaptan is extremely malodorous and voluntary exposure to high concentrations is unlikely to occur. Observations on humans are limited to a single brief report of exposure of workers to 4 ppm for 3 hours daily over 5-10 days the workers experienced headache, nausea, fatigue, and irritation of mucous membranes. ... 

Mucolytic Agents. Acetylcysteine, which is frequently used as a bronchial mucolytic agent in patients with cystic fibrosis, can be used topically in a weakened concentration for ophthalmic use. It is malodorous and may sting on instillation however, this drug is fairly effective in disrupting mucous strands that are often present in patients with aqueous deficiency dry eye. It is not commercially available in an ophthalmic formulation it must be compounded by a pharmacist. 

Dual aerated lagoons operated in series have been found to be an effective way of dealing with high BOD aqueous wastes, and with malodorous effluent as long as the TOC was less than 500 mg/L [38]. Better than 95% BOD removal has been obtained for influent BODs of 131-5,000 mg/L when retention times averaged 30 days for the first lagoon and 100 days for the second. 

Contamination of persons with malodorous substances, such as mercaptans and amines, has been proposed as a means to deter less motivated rioters based on psychological and physiological effects such as olfactory repulsion and nausea (Whitten et al., 1970). They can be delivered by frangible missile, and addition of a thickening agent will prolong adhesiveness. 

WO 01/23516 04/2001 Foley et al.l Procter Gamble Compositions that are particularly effective at masking malodors or odor suppression. Complexing agents (cyclodextrins) that have an internal cavity, forming complexes that incorporate the malodor... 

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