Biocidal activity

Carboximide, trichloromethylthio-biocidal activity mechanism, 1, 400-401 fungicide, 1, 399 Carboximides... 

Copper(II), di-/Lt-bromobis[bromo(pyridine)-structure, 2, 108 Copper 8-hydroxyquinolinate biocidal activity mechanism, 1, 401 fungicide, 1, 399 Copper nitrotetrazole as propellants, 5, 837 Copper phthalocyanine, 1, 333-334 colour and constitution, 1, 345 Coproporphyrin, 4, 382 Coproporphyrin, dehydro-, 4, 382... 

Quaternary ammonium compounds biocidal activity mechanism, 1, 401 toxicity, 1, 124 Quaternization heterocyclic compounds reviews, 1, 73 ( )-Quebrach amine synthesis, 1, 490 Queen substance synthesis, 1, 439 4, 777 Quercetin occurrence, 3, 878 pentamethyl ether photolysis, 3, 696 photooxidation, 3, 695 Quercetrin hydrolysis, 3, 878 Quinacetol sulfate as fungicide, 2, 514 Quinacridone, 2,9-dimethyl-, 1, 336 Quinacridone pigments, 1, 335-336 Quinacrine... 

Chlorine Tolerance Most of the best RO membranes are attacked by oxidants, and they are particularly susceptible to chlorine. A particularly sensitive locus for attack is the amidic hydrogen. Cellu-losic membranes are generally less sensitive, and pass the chlorine into the permeate giving downstream biocidal activity, veiy useful for under-the-sink RO. These factors are largely responsible for CA s survival in RO membranes. Chlorine, whatever its vices, has the virtue of being a known, effective, residual bactericide and a good inhibitor of... 

Dried organic deposits m inhibit penetration of the chemical agent. Where possible, objects to be disinfected should be thoroughly cleaned. The presence of ions in water can also affect activity of antimicrobial agents, thus water for testing biocidal activity can be made artifieially hard by addition of ions. 

A British Standard (BS 3286 1960) dealt specifically with the laboratoiy evaluation of the biocidal activity of QACs. This has now been revised (BS 6471 1984) and a specification (BS 6424 1984) for QAC-based aromatic disinfectants introduced. 

Several factors are known to influence biocidal activity these include the period of contact, biocide concentration, pH, temperature, the presence of oigartic matter and the nature and condition of the microorgartisms being treated. Bacterial resistance to antibiotics is a well-established phenomenon and has been widely studied for luar years. By contrast, the mechanisms of insusceptibility to non-antibiotic chemical agents are less well understood. 

Russell A.D. Russell N.J. (1995) Biocides activity, action and resistance, hi Fifty Years of Antimicrobials Past Perspectives andFuture Trends (eds P.A Himter, G.K. Derby NJ. Russell) 53rd Symposium of the Society for General Microbiology, pp. 327-365. Cambridge Cambridge University Press. 

The chemically reactive gases ethylene oxide (CH2)20, and formaldehyde (methanal, H.CHO) possess broad-spectrum biocidal activity, and have found application in the... 

There will be a long transitional period (the Directive foresees 10 years) before the Regulations come fully into effect. During the transition period existing national rules will contine to apply - that means CoPR will continue until all biocidal active substances have been reviewed under the biocides programme. 

The Directive, and implementing Regulations require that risk assessments are carried out on biocidal active substances and the products containing them. This requires the submission, and in many cases the generation of data and industry has to provide this. 

Although there are many biocide alternatives available on the market, for example enzyme technology or bio-dispersants, there appears to be a continued requirement for the use of biocides in order to reduce the levels of microbiological contamination entering the paper making process. The increased awareness of environmental and safety aspects will continue to play an important role on the selection of biocides for paper making processes. The use of legislation to select biocides must be done in parallel with each plants internal risk assessment. No one biocide active will meet all the criteria set out by different European countries and hence the use of these actives must be carefully assessed on a plant by plant basis. 

One will loose biocidal activity due to the presence of iron and manganese in the pool water because chlorine and chlorine related products will oxidize these cations ... 

In general, plant-protection products are biocidal active substances and are therefore by nature toxic to target organisms. At least some of them are also toxic to humans therefore, the safe use of plant-protection products presupposes, among other things, an evaluation of worker exposure during re-entry, an adequate risk assessment on the basis of the various practical scenarios in agriculture and horticulture, and, if necessary, specific instructions for worker protection on the product label. 

PCP was widely applied by the leather industry before the 1990s for improving the biocidal activity of raw hides and skins. Due to the risk of transformation into dioxin during burning, the use of PCP and its salts and esters in leather manufacturing is not allowed in the EU according to EU Regulation 1997/2006 (Annex XVII) [12],... 

In addition to its broad-spectrum biocidal activity, triclosan (22) displays reversible inhibition of E. coli Fabl with a picomolar K, for binding the enzyme-cofactor complex [4]. Triclosan entry results in the reordering of a loop of amino acids close to the active site, making it a slow, tight-binding inhibitor [41]. 

CEFIC has estimated that more than 60% of the 2,000 biocidal active ingredients and of the 20,000 formulated biocidal products containing them currently marketed in the EU may eventually be withdrawn as a result of the implementation of the Biocidal Products Directive. Avecia believes the BPD is likely to restrict new product development and increase the costs of notifying and listing active substances, meaning that research on new actives will be difficult to justify. Avecia Protection Hygiene develops and produces antimicrobials for more than 25 applications in industrial preservation, disinfection, plastics, textiles and personal care, and it continues to develop new products. 

As the availability of naturally durable species has declined, the industry has turned to softwoods, and increasingly to softwoods from managed forests or plantations. In order to achieve acceptable longevity under service conditions, it has been necessary to use preservatives to prevent biological attack. Such preservatives have tended to rely upon broad-spectmm biocidal activity and have become very common, particularly for exterior applications. 

FIGURE 3.9 Circulating water photoreactor system for determination of photomicro-biocidal activity under water flow conditions, a, reinforced membrane used in the study b, water jacket, continuous flow, infrared filter c, light source d, air pump e, bacterial air filter f, 3-way tap/pressure release g, 2-way taps h, frit for aeration J, peristaltic pump k, reservoir 1, ground glass Joints for ease of cleaning and sterilization (Bonnett et ai, 2006). 

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