Other Preservatives

In a survey of cosmetic allergy Schorr (1971) mentioned other cosmetic preservatives and antimicrobial agents betaines, miranols (amphoteric), dimethoxane (Dioxin), and dehydroacetic acid. How often they produce allergic reactions is unknown only a few have been reported. Dimethoxane (1.25%) sensitized 50 of 205 subjects in a Draize test (Maibach 1971). 

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Among them are cheese (limit 0.3%) (149), baked goods (limit 0.23%) (150), and margarine (limit 0.1% individually or 0.2% in combination with other preservatives) (151,152). Other permitted food categories include salad dressings (153) and condiments, where the limit of addition is generally 0.2%. Thus users must ascertain whether their particular food products are subject to a standard and, if so, what limitations apply. 

Chromium-containing wood preservatives and their chemical compositions are Hsted ia Table 13 (199). Chromium compounds have a triple function ia wood preservation (200). Most importantiy, after impregnation of the wood the Cr(VI) compounds used ia the formulations react with the wood extractives and the other preservative salts to produce relatively insoluble complexes from which preservative leaches only very slowly. This mechanism has been studied in the laboratory (201—206) and the field (207). Finally, although most of the chromium is reduced to chromium (ITT), there is probably some slight contribution of the chromium (VT) to the preservative value (208). 

Seafood. Citric acid is used in combination with other preservatives/antioxidants to lower the pH to retard microbial growth, which can lead to spoilage, formation of off-flavors, and colors on fish and other seafood products. 

Phenoxyethanol (2-phenoxyethanol). Typical in-use concentration 1%. It is more active against Ps. aeruginosa than against other bacteria and is usually combined with other preservatives such as the hydroxybenzoates to broaden the spectrum of antimicrobial activity. 

PARABEN ESTERS Typical use concentrations 0.1 - 0.3% Low toxicity Dermatologically safe at typical use concentrations Over 70 years widespread use with an extremely low incidence rate of skin response GRAS (Generally Recognised As Safe) in the USA Stable and active over a wide pH range Stable to heat Combinations of esters exhibit increased activity Approved for cosmetic applications worldwide Low water solubility Some nonionics inactivate to varying degrees May require addition of other preservatives, eg. bactericides Incompatible with some proteins... 

A number of other preservative systems are also widely applied to personal care products and are worthy of mention, some of these being used with increasing frequency, such as bronopol, methyldibromoglutaronitrile and iodopropynyl butylcarbamate, and some used with decreasing frequency, such as formalin and salicylic acid. 

Numerous studies comparing benzalkonium chloride with other preservatives have been described in the literature. Many of the articles give conflicting results, not surprising considering the many different test methods, formulas, and criteria used to arrive at these diverse conclusions. However, adequate information is available in the literature to permit the manufacturer to select... 

Incorporating ingredients or additives with antioxidant, or other preservative properties, into the food. 

Annex III lays down the conditions of use for permitted preservatives and antioxidants, with lists of foods and maximum levels in each case. Part A lists the sorbates, benzoates and p-hydroxybenzoates, E 200-E 219 part B lists sulphur dioxide and the sulphites, E 220-E 228 part C lists other preservatives with their uses, including nisin, dimethyl dicarbonate and substances allowed for surface treatment of certain fruits, E 249 potassium nitrite, E 250 sodium nitrite, E 251 sodium nitrate and E 252 potassium nitrate, E 280-E 283 propionic acid and the propionates part D lists the antioxidants E 320 butylated hydroxyanisole (BHA), E 321 butylated hydroxytoluene (BHT), E 310 propyl gallate, E 311 octyl gallate, E 312 dodecyl gallate, E 315 eiythorbic acid and E 316 sodium erythorbate. 

Acid fixation Use 1 1 HCl to adjust pH of aqueous samples to less than two. Add approx. 500 xL (2-4 drops) to 40-mL aqueous sample vials 5-mL to 1-Liter aqueous sample jars. Add acid to vials before collecting sample use gloves and eye protection when sampling. Other preservatives, such as sulfuric acid or sodium bisulfate, may also be used for this purpose. 

The potential for Bronopol to act as a preservative in mineral slurries was evaluated both alone and in combination with other preservatives. Where possible, organisms with a claimed resistance or tolerance to commonly used preservatives were used in the screening tests. 

These results point to the potential for Bronopol as a preservative in calcium carbonate slurries. In addition, they also indicate the ability of Bronopol to act as a clean-up treatment in slurries already contaminated with organisms showing tolerance or resistance to other preservatives. 

The benefits demonstrated from the preservative use of Bronopol alone and in combination with other preservatives have been realised in several other application fields, namely polymer dispersions, adhesives, paper coatings and water-based paints. By way of example, the results of a study in a water-based paint system are reported, where Bronopol is evaluated alone and in combination with 2,2-dibromodicyanobutane (DBDCB). 

Another important property is Bronopol s ability to act synergistically with other preservatives. The data presented here confirm the benefits of combining Bronopol with isothiazolinones (CIT/MIT) in mineral slurries and points to synergistic activity in combination with 2,2-dibromodicyanobutane (DBDCB) in a water-based paint system. The careful use of combinations of this sort could... 

Modem civilization consumes vast quantities of organic compounds. Coal, petroleum, and natural gas are primary sources of carbon compounds for use in production of energy and as starting materials for the preparation of plastics, synthetic fibers, dyes, agricultural chemicals, pesticides, fertilizers, detergents, rubbers and other elastomers, paints and other surface coatings, medicines and drugs, perfumes and flavors, antioxidants and other preservatives, as well as asphalts, lubricants, and solvents that are derived from petroleum. 

Benzoic acid is generally considered to exhibit an inhibitory effect on microbial growth, although it is of little use for bacterial control, where the greatest problem will occur at pH values above 4, outside the effective limit mentioned above. Improved results are obtained when it is used in conjunction with other preservatives, for example, S02 or sorbic acid, due to synergistic effects. It is interesting to note that the current European Directive, which sets individual limits of 300 rng/1 for sorbic acid and 150 mg/1 for benzoic acid in non-alcoholic flavoured drinks, nevertheless permits a joint preservative use of up to 250 mg/1 sorbic acid with 150 mg/1 benzoic acid. 

Detection and Determination of Creatinine. —This investigation is of particular importance in testing for meat extract in other preserves or in vegetable or yeast extracts. 

Tests for Antiseptics.—These are carried out as for sausages (see p. 6). Particular attention is to be paid to the tests for boric acid, salicylic add, formaldehyde and sulphur dioxide, which are more likely than other preservatives to be present in meat extracts. 

Pure, sound milk should have the normal colour, taste and smell it should contain no extraneous substances, antiseptics or other preservative agents and should contain no pathogenic micro-organisms, which are detectable by bacteriological examination and by the behaviour towards the reductase test (see 10. ). 

Pasteurised or sterilised milk is recognised by the tests already given (p. 29) it has the same composition as natural milk, and should not contain antiseptics or other preservative agents. 

Condensed milk is usually sold in soldered tins. The analysis should be made immediately after opening, since such products readily change, especially when little or np sugar has been added. Of special importance are tests for antiseptics and other preservatives (see Milk, No. 11) and heavy metals, and bacteriological examination. 

The acceptance of fruits as a staple in human diet has only been practiced since the past century because of their perishability as fresh produce. In most instances, they are used as desserts because most of them are sweet in taste and because of their high economic values. With the advent of canning and other preservation industries and with the better knowledge of nutrition, the use of fruits as staple foods has become more prevalent, especially in developed countries. 

Wood preservatives - Methods for measuring losses of active ingredients and other preservative ingredients from treated timber - Part 1 Laboratory method for obtaining samples for analysis to measure losses by evaporation to air... 

In museum collections, most invertebrates will be encountered as natural history specimens, which are divided into dry and wet-preserved. Those animals having a shell or tough exoskeleton, like starfish, shelled mollusks, and lobsters, may be dried after death. The tissue may be removed, but it is often left inside the shell or carapace to shrivel and dry. Wet-preserved specimens are usually fixed in a solution of formalin or some other preservative to prevent the tissues from deteriorating quickly after death. After a brief period, the specimen is usually removed from the toxic fixing solution, rinsed, and placed in a storage solution of 70% ethanol (alcohol) mixed with water. 

It may be necessary to differentiate between antemortem and postmortem production of alcohol in a decomposed body. Little information can be obtained from the analysis of only a single sample of blood. Samples should be taken from several different sites, as well as from the right and left chambers of the heart. These samples should each be divided into two parts, one portion being stored without a preservative and the other preserved with 1% sodium fluoride. If the unpreserved and preserved samples contain different concentrations of alcohol, this is due to the continued destruction or production of alcohol by micro-organisms in the blood. If the results of the analyses are the same, then the decomposition or production of alcohol has either not occurred or has ceased. 

Salt Salt has been a known preservation agent for centuries. Its use in dressings complements vinegar and other preservatives in producing shelf-stable dressing products. Salt also serves as an important source of zesty flavor as well as a flavor enhancer for a number of other ingredients. 

Because no flovvstone is found on the underlying cave walls, such sediments appear to have been deposited in the original cave systems when they were completely water-filled. As these deposits are nearly ubiquitous, and lie beneath most of the other preserved cave sediments, the sediment is referred to as basal fill (Sustersic, 1998b). 

The data on reported cases of neurological disorders after intrathecal chemotherapy with methotrexate or cytosine arabinoside that could be attributed to benzyl alcohol or to other preservatives have been reviewed in the context of a case of flaccid paraplegia after intrathecal administration of cytosine arabinoside diluted in bacteriostatic water containing 1.5% benzyl alcohol (1). Most commonly, flaccid paraparesis, with absent reflexes, developed rapidly, often with pain and anesthesia. Very often there was full recovery. The prognosis depended mainly on the concentration of the preservative and on the time of exposure. In some cases, the paralysis ascended to cause respiratory distress, cardiac arrest, and death. Only preservative-free sterile CSF substitute or saline, or preferably the patient s own CSF, should be used to dilute chemotherapeutic agents (SEDA-11, 475). 

Questions and answers on thiomersal have been provided by the WHO, which has underlined the fact that the risk of adverse effects of thiomersal is theoretical, uncertain, and at most extremely small (103). However, the WHO aims to replace thiomersal with other preservatives in the long term. Combination vaccines can reduce the amount of mercury to an absolute minimum. 

In ophthalmic preparations, benzalkonium chloride is one of the most widely used preservatives, at a concentration of 0.01-0.02% w/v. Often it is used in combination with other preservatives or excipients, particularly 0.1% w/v disodium edetate, to enhance its antimicrobial activity against strains of Pseudomonas. 

Bronopol 0.01-0.1% w/v is used as an antimicrobial preservative either alone or in combination with other preservatives in topical pharmaceutical formulations, cosmetics, and toiletries the usual concentration is 0.02% w/v. 

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