1、Designation: E 2361 04Standard Guide forTesting Leave-On Products Using In-Situ Methods1This standard is issued under the fixed designation E 2361; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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, su
3、ch 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 antimic
4、robial 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,
5、while other sampling methods willbe needed for testing body areas other than the hands.1.2 Methods of recovery after application of the contami-nating organisms to a part of the body other than by theagitation/rubbing of the hands against a glass petri plate alsoneed examination. Consideration shoul
6、d 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 skin.1.3 The values stated in SI units are to be regarded as thestandard.1.4 This standard does not pu
7、rport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2
8、E 1174 Test Method for Evaluation of the Effectiveness ofHealth Care Personnel or Consumer Handwash Formula-tionsE 1327 Test Method for Evaluation of Health Care Person-nel Handwash Formulations by Utilizing Fingernail Re-gions2.2 European Standard:3EN1500 Chemical Disinfectants and Antiseptics-Hygi
9、enicHandrub-Test Method Requirements (phase 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 tech
10、niquesestimate the flora remaining after antimicrobial 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.3.2 This guide was written because ASTM
11、SubcommitteeE35.15 worked on its own test method for leave-on productsused without water, but found that the EN1500 protocolencompassed the test method that had been developed.3.3 This CEN type of test methodology is widely used inEuropean and Scandinavian countries but has not been widelyused in th
12、e 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 moreappropr
13、iate. There have been criticisms of test methods, suchas EN1500, which was based on Rotters methods (1),4butpublished 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 u
14、se 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 metho
15、ds are required for testing, questions ofmethodology become clearer, and the selection of a new ordifferent sampling method is necessary.1This guide is under the jurisdiction of ASTM Committee E35 on Pesticides andAlternative Control Agents and is the direct responsibility of Subcommittee E35.15on A
16、ntimicrobial Agents.Current edition approved April 1, 2004. Published May 2004.2For 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 o
17、nthe ASTM website.3Available from 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
18、-2959, United States.3.4 When a typical hand-washing product is used, the handsare wet; scrubbing and manipulation are pursued, often vigor-ously; and rinsing follows. Agitation here is to remove organ-isms and particulate and oily soil physically. Any residue ofactive ingredient remaining on the sk
19、in 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 is a combinationof kill from the antimicrobial and the physical removal byagitation and rinsing.3.5 In contrast, leav
20、e-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 target organisms off with detergent,assuming that most of removal is transient flora, and (2)sampling in situ, for e
21、xample, 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 restricted to a very small size. Thesedifferent sampling methods disturb the deep or hidden flora todiffering degrees. T
22、here 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 as much remaining flora aspossible. The best effort, however, only removes about 15 % ofthe full thickness flora (2).
23、 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 used, the microcolonies are dispersedyielding higher counts. Washing/scrubbing methods stir up thecells and bacteria fr
24、om the deeper skin layers and release moreof the hidden flora (described by Reybrouck (3). This is alsotrue of the cup scrub method that uses detergent/surfactants todetach bacteria from the skin. Contact methods sample theflora that can easily be transferred and that is conceded to bethe most impor
25、tant in disease transmission. Williams (4) hasstated that, “although the distinction between residents andtransients must certainly be a real one, it is not to allocate thevarious bacterial species to one or other class with regularity.”3.6 There has been a long-time focus on the cup-scrubtechnique
26、only, and it would be beneficial to look at samplingspecific areas, such as Test Method E 1327, which samplesaround the fingernail region using a toothbrush, or the use ofdirect contact plating when washing is not involved (5),asinskin prepared for surgery. This guide is intended to assess theeffect
27、iveness of application of products rubbed into the skin oron the hands when these sites are not washed between uses.3.7 Superficially, the testing method is the same as withproducts that are used to scrub and wash the hands or skin inthat the hands are contaminated with a recoverable transientorgani
28、sm and the test product applied. The similarity ends here.3.8 If the hands are sampled after application of organismsand the test product in sequence, they are dried or gloved wetand are sampled after extensive rinsing. The stripping solutionis then added for sampling to increase the release of viab
29、leorganisms 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 andproduct application. Since changes have been made in TestMethod E 1327 to sample only after the first and last appl
30、ica-tions, the applicability of this test method for products rubbedinto the skin and used repeatedly without water may not beapplicable for these leave-on products.3.9 EN1500 is an adaptation of a test developed by Rotterknown as the Vienna Model (6).3.10 There are many publications describing and
31、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 bottomof a glass petri dish to release contaminating bacteria fromthese areas before and after treatment. The sample
32、d areas areonly portions of the areas treated. However, published resultshave shown consistent, statistically valid data. With theEN1500 test procedure, sampling is performed after a singleuse of the product (divided into two portions for application).4. Significance and Use4.1 The United States has
33、 concentrated attention and testingefforts on surgical scrubbing far more than on hand care inpatient-to-patient routines. Great Britain, the originators ofinfection control nursing, have always had their focus oninfection transmission. In the United States, published articleshave documented the sho
34、rt 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 that rapidly kills or removes or both themicrobial load acquired during health care activities. Theemphasis on rapidity is es
35、sential 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 has increased dramatically and theiruse is common in European countries largely because ofconvenience and effectiveness. A
36、 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 from strictly in-vitro testing of topicalantimicrobials for use on skin to simulated use testing in handwashing, prepping, sit
37、e access testing, and sampling, emphasishas always been on washing hands, agitating, rubbing, andbrushing with liquid on the skin site to estimate bacteriaremoved after testing.4.3 The use of hard agitation has diminished with surgicalscrubs without brushes or with only mild agitation and friction.4
38、.4 There is a history of microbial dispersal (7) and increasein surface bacteria from deeper layers resulting from showering(8-10), washing, scrubbing, and agitation. In the normalsituation on the skin, there is a superficial, surface flora and adeeper or hidden flora (3). The proportion of one to t
39、he otherhas been addressed by Selwyn (2) and his judgment is thatfrom 20 to 50 % of the flora is “deep.” The intent in skinsampling has almost always been to scrub, agitate, and usesurfactant to remove as many organisms as we can. In doingthis, we have completely ignored the two types of flora.4.5 F
40、urther, 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 sebumreplenishes the sebum from the sebaceous glands removed inE2361042washing. Many early investigators have looked at simplersamp
41、ling methods that we now recognize were samplingprimarily the superficial transient flora.5. Published Testing Methods for Leave-On Products5.1 Hygienic Hand RubVienna Model:5.1.1 When viable organisms are captured in the samplingfluid after exposure to a test product, sampling like that used inthe
42、glove juice test uses a much larger amount of fluid followedby microbiological analysis on a small sample. While in thetest method in EN1500 and Rotters procedure (6), the volumein the plate after rubbing the fingertips on the plates bottom iseither cultured in toto or sampled and diluted.5.1.2 With
43、 this in-situ procedure, only the fingertips aresampled in contrast to the whole hand in the glove juiceprocedure. The agitation to the fingertips in the in-situ testingis more intense than 1 min of massage of the whole hand.5.1.3 This test method has been legally mandated as theofficial CEN method
44、for their member countries. It is describedin this international standard as simulating practical conditionsfor whether a product designed as a hygienic hand rub reducesthe release of transient flora in use. The criteria specified in thestandard require that the mean reduction shall not be less than
45、achieved by a reference hand rub with propan-2-ol, 60 % (v/v).5.1.4 Rotter, in Austria, has published numerous articlesdescribing the development of this hand-rub procedure as wellas comparative studies. It has been adopted as a standard inGermany and Austria and may now be replaced with the CENstan
46、dard. Other tests with a product, for example, in-vitromicrobiological testing, are required before use, depending onthe specified use pattern. Users may want to examine themethodology published in the many trials described by Rotteret al (11) for more details than those described the Europeanstanda
47、rd. High correlation in the reductions in counts (reduc-tion factor) was found from subject to subject in the manypublished studies.5.2 Sampling Procedure Using Fingernail Regions:5.2.1 Mahl (12) published a sampling procedure for thesubungual and fingernail regions of the hand, which is also anASTM
48、 International standard, Test Method E 1327. Again, thismethodology samples a portion of the entire hand using atechnique to enhance the recovery from a difficult-to-samplearea. Fingers artificially contaminated with marker organismsthat can be enumerated after sampling are used. The fingernailareas
49、 are sampled with a toothbrush (manual or electric) in 7mL of recovery fluid in a petri dish. This methodology issimilar in concept to that used by Rotter (6) and the methodcodified in EN1500.5.2.2 This test method offers a procedure for reliablysampling a difficult area, for instance, compared to the fingertipsampling of Rotter (6) and in EN1500. Furthermore, individualfingers or combinations of fingers can be used to test more thanone test product.5.2.3 Any of the test methods for sampling the microflora ofthe skin recovers only a small fraction of that flora. Forexample, the m
