--- title: Guide for Establishing Relative Humidity Levels in Operating Rooms description: A Guide for Establishing Relative Humidity Levels in Operating Rooms image: http://www.setra.com/hubfs/Sajni/CritcalCare/ASHE_OR_Humidity_Guide-01.jpg --- ** ** ** - Website Pages - Products [![Setra Systems Logo](https://www.setra.com/hubfs/setra-logo.svg "Setra Systems Logo")](https://www.setra.com/) ![drop-down-pressure](https://www.setra.com/hs-fs/hubfs/angle-arrow-pointing-to-right.png?width=15&name=angle-arrow-pointing-to-right.png) **[Pressure Sensors](https://www.setra.com/product/pressure)** [Differential Pressure Sensors](https://www.setra.com/product/pressure/differential) [Absolute Pressure Sensors](https://www.setra.com/product/pressure/absolute) [Barometric Pressure Sensors](https://www.setra.com/product/pressure/barometric) [Compound Pressure Sensors](https://www.setra.com/product/pressure/compound) [Gauge Pressure Sensors](https://www.setra.com/product/pressure/gauge) [Submersible Pressure Sensors](https://www.setra.com/product/pressure/submersible) [Vacuum Pressure Sensors](https://www.setra.com/product/pressure/vacuum) [UHP Pressure Sensors](https://www.setra.com/product/pressure/uhp) **[Room Pressure Monitors](https://www.setra.com/product/room-pressure-monitors)** **[Pressure Calibrator](https://www.setra.com/product/calibration/microcal-pressure-calibrator)** **[Setra CEMS™ Software](https://www.setra.com/cems)** **[Power Meters & Accessories](https://www.setra.com/product/power-meters)** **[Particle Counters](https://www.setra.com/product/particle-counters)** **[Wireless Solution Systems](https://www.setra.com/wireless)** **[Humidity/Temp Sensors](https://www.setra.com/product/humidity)** **[Dolan-Jenner Fiber Optics](https://dolan-jenner.com)** ![drop-down-pressure](https://www.setra.com/hs-fs/hubfs/angle-arrow-pointing-to-right.png?width=15&name=angle-arrow-pointing-to-right.png) **[Building Automation](https://www.setra.com/building-automation)** [Calibration](https://www.setra.com/building-automation/calibration-equipment) [HVAC/R OEM](https://www.setra.com/building-automation/hvac-r-oem-applications) [HVAC/R](https://www.setra.com/building-automation/hvac-applications) **[Cleanrooms](https://www.setra.com/critical-environments)** **[Healthcare](https://www.setra.com/critical-environments/healthcare)** ![drop-down-pressure](https://www.setra.com/hs-fs/hubfs/angle-arrow-pointing-to-right.png?width=15&name=angle-arrow-pointing-to-right.png) **[General Industrial](https://www.setra.com/industrial)** [Alternative Fuels](https://www.setra.com/general-industrial/vacuum-pressure-in-alternative-fuels) [Barometric](https://www.setra.com/general-industrial/barometric-pressure-measurement-tools) [Data Centers](https://www.setra.com/applications/data-centers/pressure-sensors) [General Industrial OEM](https://www.setra.com/quality-approved-general-industrial-oem-solutions-setra-systems) [HVAC/R OEM](https://www.setra.com/building-automation/hvac-r-oem-applications) [Medical](https://www.setra.com/applications/medical-devices/pressure-sensors) [Off-Highway Vehicles](https://www.setra.com/general-industrial/pressure-transducers-for-off-highway-vehicles) [Oil & Gas](https://www.setra.com/general-industrial/oil-and-gas-pressure-measurement) [Process / MFG Tank Level](https://www.setra.com/general-industrial/liquid-level-sensors) [Test & Measurement](https://www.setra.com/general-industrial/pressure-test-and-measurement) [Water & Wastewater](https://www.setra.com/general-industrial/liquid-level-sensors-for-water-processing) **[Semiconductor Manufacturing](https://www.setra.com/semiconductor-manufacturing-pressure-measurement)** **[Data Centers](https://www.setra.com/applications/data-centers)** **[Energy Management](https://www.setra.com/energy-management)** **[Fiber Optics](https://www.setra.com/fiber-optic-illuminators)** **[Scales](https://www.setra.com/counting-scales-and-laboratory-balances)** [![setra-nav-logo.png](https://www.setra.com/hs-fs/hubfs/setra-nav-logo.png?width=133&name=setra-nav-logo.png "setra-nav-logo.png")](https://www.setra.com/) ![Menu](https://www.setra.com/hs-fs/hubfs/moble-icon.jpg?width=30&name=moble-icon.jpg) × [Home](https://www.setra.com) Markets > [Healthcare](https://www.setra.com/critical-environments/healthcare) [Building Automation](https://www.setra.com/building-automation) [Cleanrooms](https://www.setra.com/critical-environments) [General Industrial](https://www.setra.com/industrial) [Semiconductor Manufacturing](https://www.setra.com/semiconductor-manufacturing-pressure-measurement) [Data Centers](https://www.setra.com/applications/data-centers?hsLang=en) [Energy Management](https://www.setra.com/energy-management) [Fiber Optics](https://www.setra.com/fiber-optic-illuminators) [Scales](https://www.setra.com/counting-scales-and-laboratory-balances) Products > [Pressure Sensors](https://www.setra.com/product/pressure) [Room Pressure Monitors](https://www.setra.com/product/room-pressure-monitors) [Particle Counters](https://www.setra.com/product/particle-counters) [Setra CEMS™ Software](https://www.setra.com/cems) [Power Meter & Accessories](https://www.setra.com/product/power-meters) [Pressure Calibrator](https://www.setra.com/product/calibration/microcal-pressure-calibrator) [Wireless Solutions Systems](https://www.setra.com/wireless) [Humidity/Temp Sensors](https://www.setra.com/product/humidity) [Dolan-Jener](https://dolan-jenner.com/) [OEM Solutions](https://www.setra.com/custom-solutions) Resources > [Blog](https://www.setra.com/blog) [Videos](https://www.setra.com/video-resources) [FAQs](https://article.setra.com/) [Compliance](https://article.setra.com/compliance-documents) [Supplier](https://www.setra.com/support/supplier) [Current Customers](https://www.setra.com/support/customer) [Order Online](https://ecatalog.setra.com) Returns > [Services & Calibration](https://www.setra.com/support/service) [New and Unused for Credit](https://www.setra.com/product-return) [Contact Us](https://www.setra.com/help-center) # Guide for Establishing Relative Humidity Levels in Operating Rooms #### by [Brandon Rogers](https://www.setra.com/blog/author/brandon-rogers) - [Tweet](https://twitter.com/share) Successful surgery depends not only on the performance of medical professionals, but also on the integrity of the environment. [Relative humidity](https://www.setra.com/blog/how-is-humidity-measured) is a critical component in maintaining the safety and performance of an operating room (OR). In an operating room, relative humidity control is important to prevent bacteria growth, maintain the integrity of wrapped sterile equipment or supplies and to ensure the safety of the patient and operating theatre. The top priority of every facilities staff is to maintain safe conditions for high quality patient care in the OR and maintaining proper RH is the key to accomplishing this.   There are a number of considerations related to establishing relative humidity levels in an OR. Starting off, facilities should determine acceptable ranges for humidity in accordance with local regulations and accrediting agencies, as it relates to local climate. For example, [ASHE](http://www.ashe.org/) (American Society for Healthcare Engineering), based on Addendum D to Standard 170-2008, recommends an operating room range of 20% to 60% RH. Overall, the facility staff should establish a minimal relative humidity range for products, equipment and minimizing infections, to help reduce potential for undesirable situations. Below is a guide, [generated by ASHE,](http://www.ahrmm.org/advocacy/issues-topics/pdfs/joint-advisory-or-humidity-012115.pdf) for establishing relative humidity levels in operating rooms. ![ASHE_OR_Humidity_Guide-01.jpg](http://www.setra.com/hs-fs/hubfs/Sajni/CritcalCare/ASHE_OR_Humidity_Guide-01.jpg?width=680&height=597&name=ASHE_OR_Humidity_Guide-01.jpg)    **[CLICK HERE ](https://www.setra.com/products#pressure.room-pressure-monitoring)to learn about Setra’s full line of room pressure monitors. ** Topics: [Critical Environments](https://www.setra.com/blog/topic/critical-environments), [Humidity](https://www.setra.com/blog/topic/humidity), [HVAC/R](https://www.setra.com/blog/topic/hvac-r) ### Recent Posts ### Posts by Topic - [Critical Environments (184)](https://www.setra.com/blog/topic/critical-environments) - [HVAC/R (180)](https://www.setra.com/blog/topic/hvac-r) - [General Industrial (153)](https://www.setra.com/blog/topic/general-industrial) - [Building Automation (135)](https://www.setra.com/blog/topic/building-automation) - [General Industrial OEM (92)](https://www.setra.com/blog/topic/general-industrial-oem) - [Energy Management (85)](https://www.setra.com/blog/topic/energy-management) - [Test and Measurement (66)](https://www.setra.com/blog/topic/test-and-measurement) - [HVAC/R OEM (60)](https://www.setra.com/blog/topic/hvac-r-oem) - [Barometric (44)](https://www.setra.com/blog/topic/barometric) - [Alternative Fuels (42)](https://www.setra.com/blog/topic/alternative-fuels) - [Medical (41)](https://www.setra.com/blog/topic/medical) - [Process/Mfg Tank Level (40)](https://www.setra.com/blog/topic/process-mfg-tank-level) - [Water and Wastewater (39)](https://www.setra.com/blog/topic/water-and-wastewater) - [OHV (38)](https://www.setra.com/blog/topic/ohv) - [Oil and Gas (35)](https://www.setra.com/blog/topic/oil-and-gas) - [Industrial Vacuum (29)](https://www.setra.com/blog/topic/industrial-vacuum) - [Calibration (25)](https://www.setra.com/blog/topic/calibration) - [Semiconductor (25)](https://www.setra.com/blog/topic/semiconductor) - [Particle Counting (20)](https://www.setra.com/blog/topic/particle-counting) - [Cleanroom Monitoring (18)](https://www.setra.com/blog/topic/cleanroom-monitoring) - [Room Pressure Monitoring (17)](https://www.setra.com/blog/topic/room-pressure-monitoring) - [Trade Show (12)](https://www.setra.com/blog/topic/trade-show) - [cleanroom environment (12)](https://www.setra.com/blog/topic/cleanroom-environment) - [Environmental Monitoring (11)](https://www.setra.com/blog/topic/environmental-monitoring) - [Power Meters (11)](https://www.setra.com/blog/topic/power-meters) - [Scales (11)](https://www.setra.com/blog/topic/scales) - [Healthcare (10)](https://www.setra.com/blog/topic/healthcare) - [Power Monitoring (10)](https://www.setra.com/blog/topic/power-monitoring) - [Software (9)](https://www.setra.com/blog/topic/software) - [cleanroom monitoring systems (9)](https://www.setra.com/blog/topic/cleanroom-monitoring-systems) - [Case Study (8)](https://www.setra.com/blog/topic/case-study) - [critical environment technologies (8)](https://www.setra.com/blog/topic/critical-environment-technologies) - [data centers (8)](https://www.setra.com/blog/topic/data-centers) - [Humidity (7)](https://www.setra.com/blog/topic/humidity) - [particle counter (6)](https://www.setra.com/blog/topic/particle-counter) - [pressure transducers (6)](https://www.setra.com/blog/topic/pressure-transducers) - [LITE room pressure monitor (5)](https://www.setra.com/blog/topic/lite-room-pressure-monitor) - [hardware and software cleanroom monitoring systems (5)](https://www.setra.com/blog/topic/hardware-and-software-cleanroom-monitoring-systems) - [setra lite (5)](https://www.setra.com/blog/topic/setra-lite) - [Compliance (4)](https://www.setra.com/blog/topic/compliance) - [Video (3)](https://www.setra.com/blog/topic/video) - [hospital spaces (3)](https://www.setra.com/blog/topic/hospital-spaces) - [FAQ & Troubleshooting (2)](https://www.setra.com/blog/topic/faq-troubleshooting) - [Monitoring Compounding Pharmacies (2)](https://www.setra.com/blog/topic/monitoring-compounding-pharmacies) - [Semiconductor Manufacturing (2)](https://www.setra.com/blog/topic/semiconductor-manufacturing) - [agencies that monitor pharmacies (2)](https://www.setra.com/blog/topic/agencies-that-monitor-pharmacies) - [energy (2)](https://www.setra.com/blog/topic/energy) - [hvac (2)](https://www.setra.com/blog/topic/hvac) - [laboratories (2)](https://www.setra.com/blog/topic/laboratories) - [monitor compound pharmacy (2)](https://www.setra.com/blog/topic/monitor-compound-pharmacy) - [protected environment (2)](https://www.setra.com/blog/topic/protected-environment) - [regulatory compliance (2)](https://www.setra.com/blog/topic/regulatory-compliance) - [setra lite features (2)](https://www.setra.com/blog/topic/setra-lite-features) - [usp 797 (2)](https://www.setra.com/blog/topic/usp-797) - [Application Note (1)](https://www.setra.com/blog/topic/application-note) - [Current Sensors and Transducers (1)](https://www.setra.com/blog/topic/current-sensors-and-transducers) - [Current Transformers (1)](https://www.setra.com/blog/topic/current-transformers) - [Lithium-Ion Battery (1)](https://www.setra.com/blog/topic/lithium-ion-battery) - [Pressure (1)](https://www.setra.com/blog/topic/pressure) - [aerospace cleanrooms (1)](https://www.setra.com/blog/topic/aerospace-cleanrooms) - [cems (1)](https://www.setra.com/blog/topic/cems) - [digital transformation (1)](https://www.setra.com/blog/topic/digital-transformation) - [ipv6 multicast (1)](https://www.setra.com/blog/topic/ipv6-multicast) - [ipv6 multicast address (1)](https://www.setra.com/blog/topic/ipv6-multicast-address) - [ipv6 multicast address range (1)](https://www.setra.com/blog/topic/ipv6-multicast-address-range) - [isolation room pressure monitoring (1)](https://www.setra.com/blog/topic/isolation-room-pressure-monitoring) - [multicast address ipv6 (1)](https://www.setra.com/blog/topic/multicast-address-ipv6) - [multicast ipv6 (1)](https://www.setra.com/blog/topic/multicast-ipv6) - [operating room (1)](https://www.setra.com/blog/topic/operating-room) - [pharma 4.0 (1)](https://www.setra.com/blog/topic/pharma-4-0) - [pressure sensor (1)](https://www.setra.com/blog/topic/pressure-sensor) - [pressure transducer companies (1)](https://www.setra.com/blog/topic/pressure-transducer-companies) - [semi conductor (1)](https://www.setra.com/blog/topic/semi-conductor) - [sensors and transducers (1)](https://www.setra.com/blog/topic/sensors-and-transducers) - [setra pressure transducers (1)](https://www.setra.com/blog/topic/setra-pressure-transducers) - [submetering (1)](https://www.setra.com/blog/topic/submetering) - [sustainability (1)](https://www.setra.com/blog/topic/sustainability) - [temperature monitor (1)](https://www.setra.com/blog/topic/temperature-monitor) - [temperature monitoring for pharmacies (1)](https://www.setra.com/blog/topic/temperature-monitoring-for-pharmacies) - [transducers (1)](https://www.setra.com/blog/topic/transducers) - [usp 800 (1)](https://www.setra.com/blog/topic/usp-800) - [water (1)](https://www.setra.com/blog/topic/water) - [what does hvac stand for (1)](https://www.setra.com/blog/topic/what-does-hvac-stand-for) - [what is a transducer (1)](https://www.setra.com/blog/topic/what-is-a-transducer) - [what is hvac (1)](https://www.setra.com/blog/topic/what-is-hvac) [see all](https://www.setra.com/blog/guide-for-establishing-relative-humidity-levels-in-operating-rooms#) [![HVAC Catalog Cover Image 1](https://www.setra.com/hs-fs/hubfs/HVAC%20Catalog%20Cover%20Image%201.png?width=160&name=HVAC%20Catalog%20Cover%20Image%201.png "HVAC Catalog Cover Image 1")](http://setrasystems.uberflip.com/setra-systems/hvac-catalog-feb-2017)   **HVAC Catalog**   This comprehensive HVAC Product Catalog is now available online. [Download the PDF now.](http://setrasystems.uberflip.com/setra-systems/hvac-catalog-feb-2017)   - [**](https://www.facebook.com/SetraSystems) - [**](https://twitter.com/setrasystems) - [**](https://www.youtube.com/user/SetraSystems) - [**](https://www.linkedin.com/company/setra-systems) - [**](https://www.instagram.com/setrasystemsinc/) [Service & Calibration](https://www.setra.com/support/service) | [Products](https://www.setra.com/products) | [Service/RMA](https://www.setra.com/support/service) | [Supplier](https://www.setra.com/support/supplier) | [Customer](https://www.setra.com/support/customer) | [Contact Us](https://www.setra.com/contact-us) | [FAQs](https://faq.setra.com) | [About](https://www.setra.com/about) | [Careers](https://careers.fortive.com/gems-setra/) | [Request Quote](https://www.setra.com/request-a-quote) | [Blog](https://www.setra.com/blog) Cookie Settings 159 Swanson Road Boxborough, MA 01719 | [orders@setra.com](mailto:orders@setra.com) [+1 (978) 263-1400 ](tel:+19782631400) Copyright © 2026 Setra Systems. All Rights Reserved. | [Terms & Conditions](https://www.setra.com/terms-and-conditions) | [Privacy Notice](https://www.setra.com/privacy-policy) | [ISO 9001:2015 Certified | ](https://www.setra.com/hubfs/ISO%20Setra%20LLC%202025.pdf)[Prop 65](https://www.setra.com/prop65) | [Patents](https://www.setra.com/patents) | [Cookies](https://www.setra.com/cookies) [![Setra Systems Logo](https://www.setra.com/hs-fs/hubfs/setra-systems-logo_white-1.png?width=100&name=setra-systems-logo_white-1.png)](https://www.setra.com/)[![Ralliant logo](https://www.setra.com/hs-fs/hubfs/Ralliant_Logo_SingleColor_White_RGB.png?width=125&name=Ralliant_Logo_SingleColor_White_RGB.png "Setra Systems is a Ralliant Company")](https://www.ralliant.com/)