Biocides ideal

G. D. Simpson, R. F. Miller, G. D. Laxton, and W. R. Clements. A focus on chlorine dioxide the ideal biocide. In Proceedings Volume. Annu NACE Corrosion Conf (Corrosion 93) (New Orleans, LA, ill- ilVl), 1993. 

However, because the growth requirements for bacteria and fungi are ideally found in water based paint formulations and because bacteria in particular reproduce so quickly, small numbers can rapidly reach problem proportions unless they are inhibited, e.g. by the use of a suitable biocide... 

Even if all of the above properties are fulfilled, the ideal biocide will not be used if it is prohibitively expensive. The ratio of required dosage to price (its cost effectiveness) is, therefore, crucial to the success of such a product. 

Although no single active agent meets all the requirements of the ideal wet-state paint antimicrobial, one biocide group stands out as being the "best we have" and those are products based on the isothiazolin-3-one structure (Figure 14). 

Although the "ideal biocide" for the wet-state protection of paints still waits to be discovered the recent development of the methyl/benz-isothiazolinone blend offers many advantages over currently used preservatives. 

Ideally for biocidal products the guidance documents should ... 

In order to be effective under the wide range of operating conditions and environmental demands today, modem biocide programs should ideally possess at least the following ten features. 

The ideal forest operation sees the lapse time between felling and milling reduced to a week at most. For somewhat longer periods limited protection can be provided by brushing or spraying the exposed end-grain of logs with a biocide such as copper-8 quinolinolate. 

Bott [1988] has summarised these and other requirements for an ideal biocide ... 

Dust may be regarded as the ideal material for detection and identification of indoor biocides and any of their residues still existing. Commercial vacuum cleaners ean be used for taking samples. Analysis using the < 63-pm fraction of dust lead to results that are more reproducible than those for any other fraction. Reliable results are only obtained under equilibrium conditions in rooms therefore there should be no cleaning for at least one week before dust samples are taken. Since the Umweltsurveys and two case control studies published recently are based on representative samples for household du.st of the German population (especially PCP, lindane and pyrethroids), the assessment of results is possible by comparison with reference values. 

The essential characteristics that an ideal antimicrobial polymer should have include 1) simply and economically synthesised, 2) stable in long-term applications and storage at the temperature of its anticipated application, 3) not soluble in water for water disinfectant applications, 4) does not decompose to release toxic products, 5) should not be toxic or harmful to people who handle it, 6) can be regenerated upon loss of activity and 7) biocidal against a broad spectrum of pathogenic microorganisms after brief contact periods. 

In addition to its sterilising action, steam has a number of other properties which make it virtually an ideal cleaning agent/biocide and these may be summarised as ... 

In recreational water many biocides have been used either separately or in combination with other supplementary chemicals such as biocides to control algae, uv stabilizers, shock for controlling accumulation of organics, or water balance adjustment chemicals for maintaining pH, total alkalinity and calcium hardness. The ideal recreational water biocide should possess the following properties ... 

However, given the required properties of polymer dispersion biocides it is unlikely that there will ever be a true universal preservative . Development costs and regulatory and registration restrictions will prevent the development of novel molecules for polymer dispersion preservation and producers will continue to concentrate on the formulation of a number of active agents that together may fulfil the requirements of the ideal biocide. 

Gillatt, J. W., 1993. The ideal biocide for the protection water-based formulations. Spec. Chem. 18(6), 336-342. 

Small test quantities (e.g., two-ounce samples) of Nalco biocides also require proper disposal. Ideally the samples can be disposed of through addition to mill process waters where the biocides are normally fed. If the mill wastewater treatment system is large (e.g., million gallon/day volumes) it is probably safe to rinse the remains of a laboratory sample into the waste treatment system. Triple-rinse the bottles after emptying. Biocides should not be discharged to the sanitary sewer. Rinsing them into a home septic system could destroy the bacteria that treat your household sewage. The ideal disposal method is to use up the entire sample. 

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