Formaldehyde, biocidal properties

As far as the biocide properties are concerned, 0-Mannich bases containing extended hydrocarbon chains and used for their combined detcrgent/gcrmicidc action are worth mentioning. A good preserving function is also performed by plywood adhesives, based on urea, melamine, and formaldehyde, which are fixed by suitable iodo-derivatives presumably by amino- and amidomethylation reactions. 

Uses Biocide for wet-state preservation of wide range of aq., formaldehyde-sensitive prods., paints/coatings, inks preservative, biocide, bactericide, fungicide, slimicide for paper/pulp Features Solv.-free formaldehyde-free Properties Liq. 1.4-1.6% act. 

Some biocides are formaldehyde-releasing agents, and this may sometimes be the basis of their biocidal properties. Those described as sensitisers include ... 

A number of aldehydes possess antimicrobial properties, including sporicidal activity however, only two, formaldehyde and glutaraldehyde, are used for disinfection. Both these aldehydes are highly effective biocides and their use as chemosterilants reflect this. 

It does have a number of draw backs. It has poor thermal stability (a property common to most formaldehyde release biocides) and, in some instances, may cause blackening of metalworking fluid concentrates if heated above 50°C for a period of time. Recently, this active ingredient was placed on Annex 1 of the Dangerous Substances Directive having been identified as a potential skin sensitiser. This means that formulations containing efficacious levels of this class of triazine in them would have to be labelled with R43 - may cause sensitisation by skin contact. This is unacceptable to many UK customers. As this material is only bactericidal, it needs to be co-formulated with a fungicide to provide complete protection for a product. 

While the number of particles is important as they are related to health effects, so too is the size, shape, material properties and chemical composition. Chemicals absorbed or adsorbed into the particles may also have different toxicological effects. In addition to carbon particles and polycyclic aromatic hydrocarbons (PAHs), indoor air can accumulate environmental tobacco smoke as well as chemicals such as biocides, formaldehyde, and volatile organic compounds (VOCs) classified by the International Agency for Research on Cancer (lARC) as carcinogenic (benzene, 1,3-butadiene) (lARC 1995). Since children are the most affected by chronic household exposure, they may be at higher risk of cancer. It was demonstrated a relative increase in leukaemia and lymphoma caused by indoor VOCs as well as by the... 

Empirical C7H12N2O4 Properties M.w. 188.21 Toxicology LD50 (oral, rat) 2 g/kg primary irritant TSCA listed Precaution May release formaldehyde Uses Biocide antimicrobial, preservative for cosmetics, pharmaceutical topicals intermediate... 

As mentioned earlier, larval feed companies, for these reasons, have developed specialized products which contain bacteriostatic agents to keep bacterial loads within acceptable levels. These include specially treated cysts, enrichment products with bacteriostatic properties, or separate formulations which can be added to the Artemia hatching or enrichment medium. Also at the research level, several attempts have been made to disinfect Artemia nauplii (e.g. Gatesoupe, 2002 Tolomei et al., 2004 Gimenez et al., 2006). These include treatment of either cysts or the hatched nauplii with biocides (e.g. formaldehyde), UV, ozone or peroxide-based products. Apart from the fact that these treatments might cause considerable mortality to the nauplii or reduce their vigour, they might also pose potential risk to the predator larvae they are fed to, because of residues or toxic by-products produced due to these treatments. 

Mechanism of action. QACs have surfactant properties and therefore help to solubilize the cell membrane of microbial cells (Merianos, 1991). This leads to cell damage and ultimately cell death. QACs are especially effective when used in combination with other biocides that attaek the cell wall. The surfactant action exhibited by the QAC helps to make the cell wall of microbial cells more aeeessible to other biocides. The QACs facilitate penetration of biocides such as glutaraldehyde, formaldehyde, and THPS and leads to enhanced biocidal activity of these biocides. 

Formaldehyde [II, 1] and formaldehyde donors [II, 3.]. Aldehydes [II, 2.] in general are another group of biocidal actives, widely used in the past but less frequently encountered today. Mention has already been made about the advantageous property of the volatility of formaldehyde giving so-called headspace protection to closed containers. In addition formaldehyde has a rapid rate of kill and is extremely inexpensive. 

As a result, biocide manufacturers have striven to optimise the efficacy of existing active substances by producing blends with improved properties. Already mentioned have been combinations of CIT/MIT with either formaldehyde/formaldehyde donors or Bronopol which have gained very wide acceptance. 

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