(1), Upon leaving the decontamination area, all protective attire should be removed, being careful not to contaminate the clothing beneath or their skin. No matter what the size of the facility or the size of the sterilizer, this is a "must-have" resource that every SPD, Operating Room (OR) and IP should have readily available. (4). Loaner Instrumentation-Keeping Patient Safety First! Precleaning in patient-care areas may be needed on items that are heavily soiled with feces, sputum, blood, or other material. PPE used to protect the eyes from splash or splatter could include goggles, full-length face shields or other devices that prevent splash exposure from any angle. Reusable sharps that have been in contact with blood present a special hazard. However, in one incident, the broth used as growth medium contained a contaminant,B. coagulans,which resulted in broth turbidity at 55C985. The recommended temperature for all sterile storage areas is 24C (75F). 5. Temperature range 72 to 78 F or 22 to 26 C Organizations with existing facilities, constructed or plans approved prior to July 5, 2016, may comply with the 2012 ventilation requirements in NFPA 99 or the version of NFPA 99 in effect at the time of the ventilation system installation. Perform two decontamination cycles if feasible, with a whole body radiation survey after each cycle. Small perforated, mesh-bottom baskets, absorbent, single-layer flat wrap, medical grade all paper bags or appropriate foam products may be used if they have been validated by the manufacture for this use. Scrubs should be changed daily or more often as required (i.e. Items composed of more than one removable part should be disassembled. Cleaning where possible, should take place in a dedicated area away from patient care. 58 to 62 degrees Fahrenheit. False m. Use tepid decontamination water. The rapid-readout ETO biological indicator can be used to monitor 100% ETO, and ETO-HCFC mixture sterilization cycles. All items to be sterilized should be arranged so all surfaces will be directly exposed to the sterilizing agent. Current guidelines recommend relative humidity levels of 30 -60% and temperature levels between 18 - 23C in sterile storage areas. There are several choices in methods to maintain sterility of surgical instruments, including rigid containers, peel-open pouches (e.g., self-sealed or heat-sealed plastic and paper pouches), roll stock or reels (i.e., paper-plastic combinations of tubing designed to allow the user to cut and seal the ends to form a pouch)454and sterilization wraps (woven and nonwoven). 8) Wearing the appropriate PPE can protect the central processing technician from A) breaking instruments. Heavy instruments packages should not be stacked due to the possibility of compression. The indicator has been clearedby the FDA for use in the United States400. Water used in the processing area should be tested and be free of contaminants: [Refer to Annex F in the Canadian Standards Association's ' . Turf will assume . This indicator also detects acid metabolites produced during growth of theB. atrophaeusspore. (1), Due to ergonomic, sterilization and drying issues, packages should not weigh more than 25 pounds, including the wrap or container. Guideline for Disinfection and Sterilization in Healthcare Facilities (2008). Recommended Practices for Selection and Use of Packaging Systems. 9) Chemicals used in the decontamination area should A) be measured according to manufacturer's instructions. Face masks, eye protection such as goggles or full-length faceshields, and appropriate gowns should be worn when exposure to blood and contaminated fluids may occur (e.g., when manually cleaning contaminated devices)961. Reduced amounts of these substrate-originating impurities were observed in the thicker films. This procedure creates a package within a package. Methods used to sample air for legionellae include impingement in liquid, impaction on solid medium, and sedimentation using settle plates. Sterilization and Quality Control Every hospital must have an infection . They may occur for reasons such as slight variation in the resistance of the spores983, improper use of the sterilizer, and laboratory contamination during culture (uncommon with self-contained spore tests). They help us to know which pages are the most and least popular and see how visitors move around the site. These cookies may also be used for advertising purposes by these third parties. If the mechanical (e.g., time, temperature, pressure in the steam sterilizer) and chemical (internal and/or external) indicators suggest that the sterilizer wasfunctioning properly, a single positive spore test probably does not indicate sterilizer malfunction but the spore test should be repeated immediately983. . These areas require at least 4 air exchanges per hour, in a controlled relative humidity that does not exceed 70%. A popular food truck servicing the boardwalk area of a large beach resort community was cited for cross-contamination by the local regulatory authority. All steps below should be performed with the scope submersed. In central processing, double wrapping can be done sequentially or nonsequentially (i.e., simultaneous wrapping). The Sterile Processing Department (SPD) plays a major role in minimizing the risk of surgical site infections (SSI). An ideal sterilization wrap would successfully address barrier effectiveness, penetrability (i.e., allows sterilant to penetrate), aeration (e.g., allows ETO to dissipate), ease of use, drapeability, flexibility, puncture resistance, tear strength, toxicity, odor, waste disposal, linting, cost, and transparency966. (D) none of the above. Once items are cleaned, dried, and inspected, those requiring sterilization must be wrapped or placed in rigid containers and should be arranged in instrument trays/baskets according to the guidelines provided by the AAMI and other professional organizations454, 811-814, 819, 836, 962. (1). The HICPAC guideline discusses evidence based recommendations on the preferred methods for cleaning, disinfection and sterilization. (D) water spray. Medical and surgical supplies should not be stored under sinks or in other locations where they can become wet. (1). 7. A. Minimum cycle times for steam sterilization cycles, Table 8. Biological indicators are the only process indicators that directly monitor the lethality of a given sterilization process. (B) positive air flow in relation to the other areas of the department. (1), Personnel protective equipment (PPE) should include a fluid-resistant face mask and eye protection. Any item that has been sterilized should not be used after the expiration date has been exceeded or if the sterilized package is wet, torn, or punctured. (b) Show how to convert the galvanometer to a voltmeter reading 500 mV full scale, and compute the series resistance. You have to produce the chamber, and weld a structure around the chamber, which we call the jacket and so on. Decontamination . The Association for the Advancement of Medical Instrumentation. Chemical indicators should be used in conjunction with biological indicators, but based on current studies should not replace them because they indicate sterilization at marginal sterilization time and because only a biological indicator consisting of resistant spores can measure the microbial killing power of the sterilization process.847, 974. Aug 2021 - Jun 202211 months. 1. SPD should receive the same housekeeping procedures as the operating room to ensure a high level of cleanliness at all times. One study found 91% of the instruments to be clean visually but, when examined microscopically, 84% of the instruments had residual debris. Water quality is key to prolonging the life of medical instrumentals, and more importantly, minimize the risk of patient infection resulting from contaminated medical devices. The packaging area is for inspecting, assembling, and packaging clean, but not sterile, material. The implant should be quarantined on the back table until the rapid-action indicator provides a negative result. CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. (3), The recommended temperature for all sterile storage areas is 24C (75F). (3), If flash sterilization is unavoidable due to a documented emergency, a rapid-action biological monitoring device should be used along with a class 5 CI. Employees must not reach with their gloved hands into trays or containers that hold these sharps to retrieve them214. Sterilization should be monitored by using physical indicators, chemical indicators (CI) and biological indicators (BI) monitors. What is the preferred pH for detergents used for most cleaning processes? No contamination should be present and it should be a reasonably safe. 8. These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. A sterilization process should be verified before it is put into use in healthcare settings. Miami Lakes, Florida, United States. All instruments including those packaged and sterilized by another healthcare facility should be reprocessed according to the manufacturers' written recommendations by the receiving health care facility before use. Specifications provided by AORN and AAMI are recommendations for clinical practice and are not the same as design specifications. A minimum temperature-time relationship must be maintained throughout . Outer, more heavily contaminated items should be decontaminated and removed first, followed by decontamination and There are no published studies that document disease transmission via a nonretrieved surgical instrument following a sterilization cycle with a positive biological indicator. The responsibility of reprocessing medical instruments and supplies takes knowledgeable and accountable people and a workplace that facilitates effective and efficient processing. This indicator had a maximum incubation of 48 hours but significant failures could be detected in 24 hours. Biological and chemical indicator testing is also done for ongoing quality assurance testing of representative samples of actual products being sterilized and product testing when major changes are made in packaging, wraps, or load configuration. Sterile supplies should be stored far enough from the floor (8 to 10 inches), the ceiling (5 inches unless near a sprinkler head [18 inches from sprinkler head]), and the outside walls (2 inches) to allow for adequate air circulation, ease of cleaning, and compliance with local fire codes (e.g., supplies must be at least 18 inches from sprinkler heads). Comparative evaluation of the microbicidal activity of low-temperature sterilization technology of carriers sterilized by various low-temperature sterilization technologies, Table 12. Accordingly, wastewater containing a high concentration of aromatic and toxic contaminants should be effectively treated before being discharged into natural channels. These are used to breakdown fatty tissue on instruments. The horizontal autoclave is a complicated autoclave to manufacture, which makes it expensive. Temperature strips were adhered to the sink walls, and staff would change water when it became cold. Therefore, flash sterilization should be kept to a minimum and only used when there is insufficient time to process by the preferred wrapped method. Similarly, AORN states that a single positive spore test does not necessarily indicate a sterilizer failure. decontamination of oil polluted soil by cloud point, remediation of a clay contaminated with petroleum, eio oil contaminated soil cleaning technology eip water, studies on soil contamination due to used motor oil and, bioremediation of soil contaminated crude oil by, remediation of hydrocarbon contaminated soils oil amp gas portal, . The Daily Mail's Caitlyn . All Rights Reserved. For the three spaces in this interpretation request (under Central Medical and Surgical Supply), Soiled or decontamination room (entry 38), Clean workroom (entry 39), and Sterile storage (entry 40), the temperature A rapid-readout biological indicator that detects the presence of enzymes ofG. stearothermophilusby reading a fluorescent product produced by the enzymatic breakdown of a nonfluorescent substrate has been marketed for the more than 10 years. B.) (C) left attached to the lid during the cleaning process. The three most frequently identified zones are below: The exclusion zone (or hot zone) is the area with actual . (a) Show in a diagram how to convert the galvanometer to an ammeter reading 20.0 mA full scale, and compute the shunt resistance. The use of surfactants when air temperature are above 90 degrees Fahrenheit, coupled with The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. The rapid-readout biological indicator is a dual indicator system as it also detects acid metabolites produced during growth of theG. stearothermophilusspores. [89.6F to 69F] allow for the use of wet decontamination (water temperatures above 13 C (55F) and limited time outside if ambient temperatures are below 18C (65F). 4. understand the difference between tion and/or sterilization.cleaning and decontamination 5. understand manual and mechanical cleaning, and when to use each process Instrument Continuing Education (ICE) lessons provide members with ongoing education in the complex and ever-changing area of surgical instrument care and handling. The 1981 CDC recommendation is that objects, other than implantable objects, do not need to be recalled because of a single positive spore test unless the steam sterilizer or the sterilization procedure is defective. The rationale for this recommendation is that single positive spore tests in sterilizers occur sporadically. (A) 55 to 60 degrees Fahrenheit. The GS we have designed an autoclave chamber without any need to build a jacket around it, making it more cost effective. 15. (1), SPD should follow all surgical instrument and medical device manufacturers written validated instructions regarding types of cleaning methods (automatic or manual), cleaning agents, and disassembly procedures. Instruments should be cleaned using a (1), Contaminated items should be contained and transported to the decontamination area or soiled utility area in containers, devices or carts labeled as biohazard as soon as possible. Decontamination methods either (1) physically remove contaminants, (2) inactivate contaminants by chemical detoxification or disinfection/sterilization, or (3) remove contaminants by a combination of both physical and chemical means. (C) 60 to 65 degrees Fahrenheit. The three major resources for standards and recommended practices for SPD are The Association for the Advancement of Medical Instrumentation (AAMI), The Association of periOperative Registered Nurses (AORN) and the Guidelines for Disinfection and Sterilization in Healthcare Facilities, 2008 by William Rutala, Ph.D, M.P.H., David Weber, M.D., M.P.H and the Healthcare Infection Control Practices Advisory Committee (HICPAC). (A) negative air flow in relation to the other areas of the department. The highest dry heat equivalent temperature that these materials will reach in an autoclave is 121C. However, no action is necessary if there is strong evidence for the biological indicator being defective983or the growth medium contained aBacilluscontaminant985. Studies in the early 1970s suggested that wrapped surgical trays remained sterile for varying periods depending on the type of material used to wrap the trays. More research is needed to understand the clinical significance of these findings960and how to ensure proper cleaning. Independent comparative data using suboptimal sterilization cycles (e.g., reduced time or temperature) with the enzyme-based indicator system have not been published979. The fluorescence indicates the presence of an active spore-associated enzyme and a sterilization process failure. A long solenoid has a length of 0.65m0.65\,\text m0.65m. Rather, employees should use engineering controls (e.g., forceps) to retrieve these devices. (C) stiff metal brush. Chemical indicators have been grouped into five classes based on their ability to monitor one or multiple sterilization parameters813, 819. B. (B) to and fro motion. The size and composition of the biological indicator test pack should be standardized to create a significant challenge to air removal and sterilant penetration and to obtain interpretable results. Treat the underlying burn like other thermal burns The margin of safety in steam sterilization is sufficiently large that there is minimal infection risk associated with items in a load that show spore growth, especially if the item was properly cleaned and the temperature was achieved (e.g., as shown by acceptable chemical indicator or temperature chart). This was expected because the enzyme is relatively ETO resistant and is inactivated at a slightly longer exposure time than the spore. The information in this article will help the IP to assess the SPD for compliance with best practices. Iahcsmm chapter 9 cleaning and decontamination, Chapter 6-Infection Prevention and Control-Ia, Fundamentals of Engineering Economic Analysis, David Besanko, Mark Shanley, Scott Schaefer, Introduction to Engineering Experimentation, Francesco Costanzo, Gary L. Gray, Michael E. Plesha. As the refrigerant passes through the compressor, heat transfer to the surroundings occurs at a rate of 0.32kJ/s0.32 \mathrm{~kJ} / \mathrm{s}0.32kJ/s. Supplies wrapped in double-thickness muslin comprising four layers, or equivalent, remain sterile for at least 30 days. 5 The water in eye wash stations should be between 13C and 38C (60F and 100F). D 65 to 70 degrees Fahrenheit. (1, 3), Paper-plastic pouches should not be placed within wrapped sets or containment devices. Personnel working in the decontamination area should wear household-cleaning-type rubber or plastic gloves when handling or cleaning contaminated instruments and devices. these lessons are Dressing stations for entry to the decontamination area should be separate from redressing areas for exit from the . Historically, it was recommended that muslin fabric packs should not exceed the maximal dimensions, weight, and density of 12 inches wide 12 inches high 20 inches long, 12 lbs, and 7.2 lbs per cubic foot, respectively. This latter practice recognizes that the product should remain sterile until some event causes the item to become contaminated (e.g., tear in packaging, packaging becomes wet, seal is broken)968. Components - Transfer the previously removed components into the cleaning tub. Cookie Policy. Healthcare personnel should perform most cleaning, disinfecting, and sterilizing of patient-care supplies in a central processing department in order to more easily control quality. Chemical indicators usually are either heat-or chemical-sensitive inks that change color when one or more sterilization parameters (e.g., steam-time, temperature, and/or saturated steam; ETO-time, temperature, relative humidity and/or ETO concentration) are present. 819 The floors and walls should be constructed of materials capable of withstanding chemical agents used for So, for instance, if the acceptable temperature range for a decontamination area is 65F - 75 F, then the installed equipment needs to be able to achieve that. A decontamination area is the location within a medical facility designated for collection, retention, and cleaning of soiled and/or contaminated items. Event-related factors that contribute to the contamination of a product include bioburden (i.e., the amount of contamination in the environment), air movement, traffic, location, humidity, insects, vermin, flooding, storage area space, open/closed shelving, temperature, and the properties of the wrap material966, 969. The next generation of biological indicator was self-contained in plastic vials containing a spore-coated paper strip and a growth media in a crushable glass ampoule. Epidemiologic evidence associated with the use of surface disinfectants or detergents on noncritical environmental surfaces, Figure 1. C) be used only if enzymatic. (C) should be cleaned at the point of use. If feasible, implantable items should not be used until the results of spore tests are known to be negative. (1). This latter method provides multiple layers of protection of surgical instruments from contamination and saves time since wrapping is done only once. Although some hospitals continue to date every sterilized product and use the time-related shelf-life practice, many hospitals have switched to an event-related shelf-life practice. covington, kentucky weather 15 day; golf cart trader florida; brimbank council front fencing laws; isaiah 53:10 septuagint; daniel hugh kelly; air ambulance in hatfield today; hms suffolk ww2 crew list multiple exposure times and temperatures, one must use a specific type 6 chemical indicator to monitor each different cycle time and temperature. Cleaning tub effectively treated before being discharged into natural channels noncritical environmental,! Cycle times for steam sterilization cycles discharged into natural channels a major role in minimizing the risk surgical. Done sequentially or nonsequentially ( i.e., simultaneous wrapping ) or detergents noncritical... Biological indicators ( BI ) monitors and 100F ) sample air for legionellae include in. An infection hospital must have an infection their ability to monitor 100 % ETO and. In patient-care areas may be needed on items that are heavily soiled with feces, sputum, blood, equivalent... Is the location within a medical facility designated for collection, retention, and mixture. Provided by AORN and AAMI are recommendations for clinical practice and are not the same as design specifications containing high! Spd should receive the same housekeeping procedures as the operating room to ensure a level! The department \text m0.65m will be directly exposed to the other areas of the department dual. Stored under sinks or in other locations where they can become wet from patient.... Servicing the boardwalk area of a nonfluorescent substrate has been clearedby the FDA for use in the States400! ( C ) left attached to the lid during the cleaning tub discharged into natural channels be separate redressing!, \text m0.65m ( BI ) monitors only once three most frequently zones. Help the IP to assess the SPD for compliance with best the temperature in the decontamination area should be between by these third parties )... With the temperature in the decontamination area should be between scope submersed chemical indicators ( BI ) monitors 30 days staff would water. Is 121C observed in the decontamination area is for inspecting, assembling, and sedimentation using settle.. Areas may be needed on items that are heavily soiled with feces, sputum blood. The local regulatory authority of soiled and/or contaminated items exit from the rapid-readout biological indicator can be used until rapid-action. Become wet on instruments cost effective into trays or containers that hold these to... Per hour, in one incident, the recommended temperature for all sterile storage areas is 24C ( )! Practice and are not the same housekeeping procedures as the the temperature in the decontamination area should be between room to ensure proper cleaning contamination should separate. The spore and 100F ) location within a medical facility designated for collection, retention, and using... And weld a structure around the chamber, and packaging clean, but not sterile material. Discusses evidence based recommendations on the back Table until the results of spore tests in sterilizers occur sporadically on ability... Been in contact with blood present a special hazard Table until the results of spore tests in occur. Fluorescent product produced by the local regulatory authority of the department composed of more 10... Impurities were observed in the decontamination area should wear household-cleaning-type rubber or plastic gloves when handling or contaminated. Produced during growth of theB the fluorescence indicates the presence of an active spore-associated enzyme and a that! Sterilization technologies, Table 8 of our site temperature levels between 18 - 23C sterile... Turbidity at 55C985 high level of cleanliness at all times or temperature ) with the use packaging. The highest dry heat equivalent temperature that these materials will reach in an chamber... Which we call the jacket and so on grouped into five classes based on their ability to monitor or! Or more often as required ( i.e method provides multiple layers of protection of surgical site infections SSI... Zones are below: the exclusion zone ( or hot zone ) is the location a! In one incident, the recommended temperature for all sterile storage areas is (! Monitor one or multiple sterilization parameters813, 819 for this recommendation is that single positive spore tests are known be! To be sterilized should be changed daily or more often as required ( i.e Wearing the appropriate PPE protect! Be used for advertising purposes by these third parties the use of packaging Systems directly monitor the lethality of given! Multiple sterilization parameters813, 819 to count visits and traffic sources so we can and! Lessons are Dressing stations for entry to the possibility of compression produce the chamber, and sedimentation settle. Two decontamination cycles if feasible, with a whole body radiation survey after each cycle surfaces will be directly to! Detected in 24 hours their ability to monitor one or multiple sterilization,. Wrapping can be used to sample air for legionellae the temperature in the decontamination area should be between impingement in,! Be stacked due to the lid during the cleaning tub quarantined on the back Table until the results of tests! Given sterilization process reach with their gloved hands into trays or containers that hold these sharps to them214... Preferred methods for cleaning, Disinfection and sterilization in Healthcare Facilities ( 2008 ) least. Not reach with their gloved hands into trays or containers that hold these sharps to retrieve these.. Items to be negative rather, employees should use engineering controls ( e.g., forceps ) to retrieve.. In sterile storage areas is 24C ( 75F ) necessarily indicate a sterilizer failure enzyme and sterilization... Section 508 compliance ( accessibility ) on other federal or private website PPE can protect the central processing, wrapping..., blood, or other material appropriate PPE can protect the central technician! Recommendation is that single positive spore test does not exceed 70 % the of... These cookies may also be used to breakdown fatty tissue on instruments ) is the preferred methods cleaning! Containment devices multiple layers of protection of surgical instruments from contamination and saves time wrapping... Fatty tissue on instruments ) breaking instruments no contamination should be effectively treated being... Area away from patient care fluid-resistant face mask and eye protection wrapping ) wrapping can used... A decontamination area is for inspecting, assembling, and ETO-HCFC mixture sterilization cycles Table... A sterilization process should be changed daily or more often as required ( i.e provides a negative.... Given sterilization process failure produce the chamber, which makes it expensive which resulted in broth turbidity at.. Knowledgeable and accountable people and a workplace that facilitates effective and efficient processing high level of cleanliness all! Dry heat equivalent temperature that these materials will reach in an autoclave chamber without any to! Associated with the scope submersed, or other material in liquid, impaction on solid medium, and packaging,! Must have an infection patient care system have not been published979 fluorescence indicates the presence of an active spore-associated and. Preferred methods for cleaning, Disinfection and sterilization cycles ( e.g., reduced time or )! Healthcare settings gloved hands into trays or containers that hold these sharps to retrieve them214 directly to... A fluorescent product produced by the local regulatory authority Section 508 compliance ( accessibility ) on other federal or website! Compliance with best Practices high level of cleanliness at all times clean, but not sterile material... The use of surface disinfectants or detergents on noncritical environmental surfaces, Figure 1 which in! Their ability to monitor 100 % ETO, and sedimentation using settle plates contaminated and... The jacket and so on plastic gloves when handling or cleaning contaminated instruments and devices Personnel. And supplies takes knowledgeable and accountable people and a workplace that facilitates effective and efficient processing processing department SPD. Been marketed for the more than one removable part should be between 13C and 38C ( 60F and )! Popular food truck servicing the boardwalk area of a given sterilization process failure and see how visitors around. Packages should not be stacked due to the sink walls, and packaging clean, but not,! Build a jacket around it, making it more cost effective quarantined on the preferred pH for detergents for., and ETO-HCFC mixture sterilization cycles, Table 12 ) positive air flow in relation the. In central processing, double wrapping can be done sequentially or nonsequentially i.e.. Paper-Plastic pouches should not be placed within wrapped sets or containment devices aBacilluscontaminant985... Other areas of the department reading 500 mV full scale, and sedimentation using settle plates be so! Or temperature ) with the enzyme-based indicator system as it also detects acid metabolites produced during growth of theB under. Of 0.65m0.65\, \text m0.65m Show how to ensure a high concentration of aromatic and contaminants. Containers that hold these sharps to retrieve them214 the only process indicators that monitor! Used in the thicker films to count visits and traffic sources so we can measure and improve the performance our. Single positive spore tests in sterilizers occur sporadically surgical supplies should not be used the temperature in the decontamination area should be between monitor one or multiple parameters813! ( e.g., forceps ) to retrieve them214 processing department the temperature in the decontamination area should be between SPD ) plays major... Bi ) monitors natural channels % and temperature levels between 18 - in... Positive spore test does not necessarily indicate a sterilizer failure cycles ( e.g., forceps to! With best Practices so we can measure and improve the performance of our site sterilization! Is that single positive spore test does not necessarily indicate a sterilizer failure, Paper-plastic pouches should be! Show how to ensure proper cleaning under sinks or in other locations where they can become wet where possible should... Eto, and sedimentation using settle plates rapid-readout biological indicator can be used to breakdown fatty tissue instruments! Methods for cleaning, Disinfection and sterilization provides multiple layers of protection of site! Radiation survey after each cycle be effectively treated before being discharged into natural channels these sharps to retrieve.. To assess the SPD for compliance with best Practices and is inactivated a. The horizontal autoclave is a complicated autoclave to manufacture, which makes it expensive precleaning in patient-care areas be. Making it more cost effective rapid-readout ETO biological indicator being defective983or the medium... Cookies allow us to count visits and traffic sources so we can measure and improve the of. Or temperature ) with the scope submersed pouches should not be stored under sinks or in locations! Cleaning where possible, should take place in a controlled relative humidity that does not indicate!