1、Designation: E2361 13Standard Guide forTesting Leave-On Products Using In-Situ Methods1This standard is issued under the fixed designation E2361; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers test methods and sampling procedureoptions for leave-on products for consumer and hospitalpersonnel. Leave-on products, such
3、as alcohol hand rubs andlotions containing antimicrobial ingredients, are increasinglymarketed and used by consumers and health care personnel.These products are distinguished from conventional washingand scrubbing preparations in that they do not rely on therinsing, physical removal, and antimicrob
4、ial action in deter-mining their effectiveness. Although agitation and friction mayserve to release organisms from the skin and folds and crevices,organisms are then killed in situ and are not rinsed from theskin surface before sampling. Appropriate test methods for thehands have been published, whi
5、le other sampling methods willbe needed for testing body areas other than the hands.1.1.1 Researchers have described techniques to identify theexpanded flora we now know can be present on the skin. It isimpractical, if not prohibitive to attempt to recover and identifythese varieties of organisms wi
6、th each test.At some point in thedesign of a test, a decision is necessary for defining the targetorganisms. Should the sampling be designed to recover asmuch of the microflora as possible or a particular portion of it?Consideration of transient and resident, superficial and deep, oraerobic and anae
7、robic flora must be included in defining theobjective in testing products. The recovery methods selectedfor any testing must be based on the projected use of theproduct type being tested.1.2 Methods of recovery after application of the contami-nating organisms to a part of the body other than by the
8、agitation/rubbing of the hands against a glass petri plate alsoneed examination. Consideration should be given to contactplating, controlled swabbing with a template, and cup scrub-bing (detergent/agitation used) since the target organisms forrecovery are likely to be on the superficial layers of sk
9、in.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish a
10、ppro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2E1174 Test Method for Evaluation of the Effectiveness ofHealth Care Personnel Handwash FormulationsE1327 Test Method for Evaluation of Antimicro
11、bial Hand-wash Formulations by Utilizing Fingernail RegionsE2755 Test Method for Determining the Bacteria-Eliminating Effectiveness of Hand Sanitizer FormulationsUsing Hands of Adults2.2 European Standard:3EN1500 Chemical Disinfectants and Antiseptics-HygienicHandrub-Test Method Requirements (phase
12、2/step 2)approved by CEN (Comit Europen de Normalisation)3. Summary of Guide3.1 In this guide, choices of recovery techniques after theuse of antimicrobial products will be considered. By the natureof the distribution of the skin flora, these sampling techniquesestimate the flora remaining after ant
13、imicrobial use; some of itis superficial and some hidden. An appropriate samplingmethod can be selected depending on product use and theimportance of superficial (transient) and hidden or deep(mostly resident) flora. Recent publications have revealed agreater variety of organisms that populate the s
14、kin and com-prise the skin microbiome (1, 2).4This information requires alarger selection of recovery media. For certain applications,such as acne studies or when recovery of the greatest diversityof organisms is desired, specific anaerobic/microaerophilicmedia should be used.1This guide is under th
15、e jurisdiction of ASTM Committee E35 on Pesticides,Antimicrobials, and Alternative Control Agents and is the direct responsibility ofSubcommittee E35.15 on Antimicrobial Agents.Current edition approved April 1, 2013. Published June 2013. Originallyapproved in 2004. Last previous edition approved in
16、2007 as E2361 04 (2007).DOI: 10.1520/E2361-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from
17、 British Standards Institute (BSI), 389 Chiswick High Rd.,London W4 4AL, U.K.4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2 This guid
18、e was originally written because ASTM Sub-committee E35.15 worked on its own test method for leave-onproducts used without water, but found that the EN1500protocol encompassed the test method that had been devel-oped. In 2010, a new standard test method specifically de-signed to evaluate the efficac
19、y of leave-on product wasapproved under the designation Test Method E2755. This guidehas now been updated to cover Test Method E2755.3.3 ASTM has Test Method E1174 to test water-aidedhandwash products for health-care personnel. This test methodincludes both wash-off and leave-on products. It has bee
20、nrevised (E117413) to include special instructions for leave-onproducts to use another Test Method E2755(11) that has beenpublished for testing leave-on hand treatment products.3.4 This CEN type of test methodology is widely used inEuropean and Scandinavian countries but has not been widelyused in t
21、he United States, although the use of alcohol/alcoholgel hand rubs has expanded greatly here in the last few years.The underlying question is whether a test method designed fora leave-on product like alcohol or the conventional handwashing followed by sampling in a glove or plastic bag is moreapprop
22、riate. There have been criticisms of test methods, suchas EN1500, which was based on Rotters methods (3), butpublished data confirm that the test is highly reliable inshowing consistent reduction levels with low variation fromsubject to subject. Leave-on products that are not rinsed orwashed off in
23、use are primarily represented by alcohol-basedhand rubs. However, other leave-on formulations have beenintroduced and, undoubtedly, their number will increase in thefuture. Often test methods designed for washing/rinsing pro-cedures have been used for these products. When differentmore specific meth
24、ods are required for testing, questions ofmethodology become clearer, and the selection of a new ordifferent sampling method is necessary.3.5 When a typical hand-washing product is used, the handsare wet; scrubbing and manipulation are pursued, often vigor-ously; and rinsing follows. Agitation here
25、is to remove organ-isms and particulate and oily soil physically. Any residue ofactive ingredient remaining on the skin is a small fraction ofthe amount applied and assumed to be attached to the stratumcorneum. The residual may also be absorbed over time.Ultimately, the reduction in microbial count
26、is a combinationof kill from the antimicrobial and the physical removal byagitation and rinsing.3.6 In contrast, leave-on products, such as alcohol productsintended to be applied and not rinsed off, present a differentsituation. There are two distinct techniques when sampling: (1)sampling by washing
27、 target organisms off with detergent,assuming that most of removal is transient flora, and (2)sampling in situ, for example, the cup scrub, swab, contactplate, or velvet block/pad that sample bacteria by impressionand contact or by using fluid to remove samples so that thevolume of the sample is res
28、tricted to a very small size. Thesedifferent sampling methods disturb the deep or hidden flora todiffering degrees. There has been an overwhelming concentra-tion of the cup-scrub sampling method as various test methodshave been developed. The combination of detergent andagitation attempts to remove
29、as much remaining flora aspossible. The best effort, however, only removes about 15 % ofthe full thickness flora (4). When other contact sampling ortape stripping are used, the distribution of bacterial colonies onthe skin are mirrored as they occur; whereas, if detergent/scrubbing techniques are us
30、ed, the microcolonies are dispersedyielding higher counts. Washing/scrubbing methods stir up thecells and bacteria from the deeper skin layers and release moreof the hidden flora (described by Reybrouck (5). This is alsotrue of the cup scrub method that uses detergent/surfactants todetach bacteria f
31、rom the skin. Contact methods sample theflora that can easily be transferred and that is conceded to bethe most important in disease transmission. Williams (6) hasstated that, “although the distinction between residents andtransients must certainly be a real one, it is not to allocate thevarious bac
32、terial species to one or other class with regularity.”3.7 There has been a long-time focus on the cup-scrubtechnique only, and it would be beneficial to look at samplingspecific areas, such as Test Method E1327, which samplesaround the fingernail region using a toothbrush, or the use ofdirect contac
33、t plating when washing is not involved (7),asinskin prepared for surgery. This guide is intended to assess theeffectiveness of application of products rubbed into the skin oron the hands when these sites are not washed between uses.3.8 Superficially, the testing method is the same as withproducts th
34、at are used to scrub and wash the hands or skin inthat the hands are contaminated with a recoverable transientorganism and the test product applied. The similarity ends here.3.9 If the hands are sampled after application of organismsand the test product in sequence, they are dried or gloved wetand a
35、re sampled after extensive rinsing. The stripping solutionis then added for sampling to increase the release of viableorganisms to be recovered. In contrast, in testing for hand rubsor leave-on products, glove sampling would seem appropriateonly if sampling were performed after each contamination an
36、dproduct application. Since changes have been made in TestMethod E1327 to sample only after the first and lastapplications, the applicability of this test method for productsrubbed into the skin and used repeatedly without water may notbe applicable for these leave-on products.3.10 EN1500 is an adap
37、tation of a test developed by Rotterknown as the Vienna Model (8).3.11 There are many publications describing and evaluatingfingertip-sampling methods. One of the major criticisms of themethods is the procedure used for sampling. The tips of thefingers and thumb are sampled by rubbing against the bo
38、ttomof a glass petri dish to release contaminating bacteria fromthese areas before and after treatment. The sampled areas areonly portions of the areas treated. However, published resultshave shown consistent, statistically valid data. With theEN1500 test procedure, sampling is performed after a sin
39、gleuse of the product (divided into two portions for application).4. Significance and Use4.1 The United States has concentrated attention and testingefforts on surgical scrubbing far more than on hand care inpatient-to-patient routines. Great Britain, the originators ofE2361 132infection control nur
40、sing, have always had their focus oninfection transmission. In the United States, published articleshave documented the short exposure time for health carepersonnel who do wash their hands between patients. Theaverage is less than 10 s. The ideal product for the reduction oftransient flora is one th
41、at rapidly kills or removes or both themicrobial load acquired during health care activities. Theemphasis on rapidity is essential simply because health carepersonnel will not take the necessary time when using conven-tional hand-washing products. The use of products not in-tended for use with water
42、 has increased dramatically and theiruse is common in European countries largely because ofconvenience and effectiveness. A second characteristic is thelevel of antimicrobial action. The use of a rapid and potentactive product to reduce work-acquired microbial flora is ideal.4.2 Since the change fro
43、m strictly in-vitro testing of topicalantimicrobials for use on skin to simulated use testing in handwashing, prepping, site access testing, and sampling, emphasishas always been on washing hands, agitating, rubbing, andbrushing with liquid on the skin site to estimate bacteriaremoved after testing.
44、4.3 The use of hard agitation has diminished with surgicalscrubs without brushes or with only mild agitation and friction.4.4 There is a history of microbial dispersal (9) and increasein surface bacteria from deeper layers resulting from showering(10-12), washing, scrubbing, and agitation. In the no
45、rmalsituation on the skin, there is a superficial, surface flora and adeeper or hidden flora (5). The proportion of one to the otherhas been addressed by Selwyn (4) and his judgment is thatfrom 20 to 50 % of the flora is “deep.” The intent in skinsampling has almost always been to scrub, agitate, an
46、d usesurfactant to remove as many organisms as we can. In doingthis, we have completely ignored the two types of flora.4.5 Further, when the skin is treated with a cleansing agentor an antimicrobial that is subsequently rinsed away, the“deep” or “hidden” flora is pushed to the surface as the sebumre
47、plenishes the sebum from the sebaceous glands removed inwashing. Many early investigators have looked at simplersampling methods that we now recognize were samplingprimarily the superficial transient flora.5. Published Testing Methods for Leave-On Products5.1 Low Volume Contamination:5.1.1 Prior to
48、2010, ASTM did not have a standard testmethod specifically designed for testing leave-on hand hygieneproducts. In the absence of such a method, products were testedaccording to the Healthcare Personnel Handwashmethodology, Test Method E1174, which was originally de-signed to test water-aided handwas
49、h products.5.1.2 Test Method E1174 measures the reduction of atransient marker organism (Serratia marcescens) introduced tothe hands in the form of a 24-h saturated liquid broth culture(4.5 mL total). Hands are sampled via the glove juice proce-dure. Test products are evaluated after a single application andafter ten consecutive hand contamination and product applica-tion cycles. The method presents several technical issues whenevaluating leave-on products. The large volume of challengeorganism often remains wet on the hands when the test productis applied thus diluting the ac
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