{"id":494,"date":"2026-10-21T01:41:21","date_gmt":"2026-10-21T01:41:21","guid":{"rendered":"https:\/\/fenggu-bio.com\/?p=494"},"modified":"2026-10-21T01:41:21","modified_gmt":"2026-10-21T01:41:21","slug":"how-to-write-vhp-urs","status":"publish","type":"post","link":"https:\/\/fenggu-bio.com\/pt\/how-to-write-vhp-urs\/","title":{"rendered":"Como redigir uma URS para um sistema de descontamina\u00e7\u00e3o VHP"},"content":{"rendered":"<style>\n.entry-title,.ast-single-post .entry-header{display:none!important}\n.fg-art{font-family:-apple-system,BlinkMacSystemFont,\"Segoe UI\",Roboto,\"Helvetica Neue\",Arial,sans-serif;color:#1e2838;line-height:1.85;max-width:820px;margin:0 auto;padding:0 22px;font-size:16.5px}\n.fg-art .fg-eyebrow{display:inline-block;background:#e3ecfa;color:#003AA1;font-weight:700;font-size:12px;letter-spacing:.7px;padding:5px 13px;border-radius:20px;margin:34px 0 14px}\n.fg-art h1{font-size:29px;line-height:1.32;color:#002B78;margin:0 0 12px;font-weight:800}\n.fg-art .meta{font-size:13.5px;color:#7a8699;margin:0 0 26px;border-bottom:1px solid #e6ebf3;padding-bottom:18px}\n.fg-art h2{font-size:22px;color:#002B78;margin:38px 0 12px;line-height:1.35}\n.fg-art h3{font-size:17.5px;color:#003AA1;margin:22px 0 8px}\n.fg-art p{margin:0 0 16px}\n.fg-art .lead{font-size:18px;color:#3a4658}\n.fg-art figure{margin:26px 0}\n.fg-art img{width:100%;border-radius:12px;box-shadow:0 6px 22px rgba(0,58,161,.12);display:block}\n.fg-art svg{width:100%;height:auto;display:block;border-radius:12px}\n.fg-art figcaption{font-size:13px;color:#7a8699;margin-top:9px;text-align:center}\n.fg-art table{border-collapse:collapse;width:100%;margin:22px 0;font-size:14.5px}\n.fg-art th,.fg-art td{border:1px solid #d7dfea;padding:11px 14px;text-align:left;vertical-align:top}\n.fg-art thead th{background:#002B78;color:#fff;font-weight:700}\n.fg-art tbody th{background:#eff4fb;color:#002B78;font-weight:700;width:22%}\n.fg-art tbody tr:nth-child(even) td{background:#f7f9fc}\n.fg-art ul{margin:0 0 16px;padding-left:22px}.fg-art li{margin:7px 0}\n.fg-art .fg-cta{background:linear-gradient(120deg,#002B78,#003AA1);color:#fff;border-radius:14px;padding:30px 28px;margin:38px 0 10px;text-align:center}\n.fg-art .fg-cta h3{color:#fff;font-size:22px;margin:0 0 8px}\n.fg-art .fg-cta p{color:#dce7f7;margin:0 0 18px;font-size:15.5px}\n.fg-art .fg-btn{display:inline-block;background:#EC001B;color:#fff;padding:13px 28px;border-radius:6px;font-weight:600;font-size:15.5px;text-decoration:none;margin:0 6px 8px}\n.fg-art .fg-btn.o{background:transparent;border:2px solid rgba(255,255,255,.7)}\n.fg-art a{color:#003AA1;text-decoration:underline}\n.fg-art .fg-cta a{text-decoration:none;color:#fff}\n@media(max-width:640px){.fg-art h1{font-size:24px}.fg-art th,.fg-art td{padding:9px 10px;font-size:13.5px}}\n<\/style>\n<article class=\"fg-art\">\n<span class=\"fg-eyebrow\">VHP Sterilization &middot; Buyer&rsquo;s Guide<\/span><\/p>\n<h1>How to Write a URS for a VHP Decontamination System<\/h1>\n<div class=\"meta\">Fenggu Pharmaceutical Equipment &middot; VHP Sterilization &amp; Contamination Control<\/div>\n<p class=\"lead\">A user requirement specification (URS) is the document that tells suppliers what your VHP decontamination system must do, and later tells your validation team what to test. A good URS gets you comparable quotations and a smooth qualification. A weak one gets you a catalogue machine, missing interfaces and arguments at commissioning. This guide sets out the sections a VHP URS needs, gives example requirements you can adapt, and lists the mistakes to avoid.<\/p>\n<p>Before you start, it helps to know how to read VHP equipment data: see <a href=\"\/vhp-generator-specifications\/\">VHP generator specifications explained<\/a>. Once the URS is written, use <a href=\"\/vhp-sterilization-system-supplier\/\">12 questions to evaluate a VHP supplier<\/a> to compare the answers.<\/p>\n<h2>Why a VHP system needs its own URS<\/h2>\n<p>In a GMP project, the URS is the start of the qualification chain. The supplier answers it with a design or functional specification, and every critical requirement must later be traced to a test in IQ, OQ or PQ. If a requirement is not in the URS, nobody is obliged to design it or test it.<\/p>\n<p>VHP systems are particularly sensitive to this, because their performance depends on things outside the generator: the room or equipment they treat, the HVAC system, the BMS, door interlocks and the people who run them. A URS that only describes the generator leaves all of those interfaces undefined.<\/p>\n<h2>Before you write: collect the inputs<\/h2>\n<p>The URS is only as good as the information behind it. Collect these first:<\/p>\n<ul>\n<li><strong>What must be treated:<\/strong> rooms, a cleanroom suite and its ductwork, equipment interiors (lyophilizers, isolators, biosafety cabinets), pass boxes, airlocks or HEPA filter housings.<\/li>\n<li><strong>Volumes and layout:<\/strong> room volumes, number of rooms and doors, duct volumes, and drawings.<\/li>\n<li><strong>HVAC data:<\/strong> air-handling units serving the area, recirculation or once-through, damper positions, available fresh air and exhaust for aeration.<\/li>\n<li><strong>Materials:<\/strong> wall and ceiling panels, sealants, gaskets, equipment and electronics that will be exposed to hydrogen peroxide.<\/li>\n<li><strong>Operating scenarios:<\/strong> routine decontamination, before or after maintenance, after a contamination event, campaign changeover.<\/li>\n<li><strong>Constraints:<\/strong> available downtime, utilities, plant room space, site power supply.<\/li>\n<\/ul>\n<p>This is also the point to decide the type of system. If you are unsure, compare <a href=\"\/vhp-generator-portable-vs-integrated\/\">portable and integrated VHP generators<\/a> for rooms, or <a href=\"\/pulsed-vacuum-vs-recirculating-vhp-generator\/\">pulsed-vacuum and recirculating generators<\/a> for equipment.<\/p>\n<h2>The sections of a VHP URS<\/h2>\n<p>Most VHP URS documents follow the structure below. Adapt it to your site&rsquo;s URS template.<\/p>\n<div style=\"overflow-x:auto\">\n<table>\n<thead>\n<tr>\n<th>Section<\/th>\n<th>What it should define<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th>1. Scope and intended use<\/th>\n<td>What the system treats, which operating scenarios it covers, and what is out of scope.<\/td>\n<\/tr>\n<tr>\n<th>2. Enclosures<\/th>\n<td>Each room, suite, duct section or piece of equipment, with volume, materials and drawings in an appendix.<\/td>\n<\/tr>\n<tr>\n<th>3. Performance<\/th>\n<td>Efficacy target and how it is demonstrated, maximum total cycle time, release criterion after aeration, repeatability.<\/td>\n<\/tr>\n<tr>\n<th>4. Process conditions<\/th>\n<td>Temperature and humidity at the start of the cycle, who is responsible for reaching them, utilities available.<\/td>\n<\/tr>\n<tr>\n<th>5. Equipment design<\/th>\n<td>Materials in contact with hydrogen peroxide, sterilant, sensors, aeration method, mobility or fixed installation, footprint.<\/td>\n<\/tr>\n<tr>\n<th>6. Controls and data integrity<\/th>\n<td>Control system, user levels, audit trail, recipes, alarms, data storage and export, electronic records.<\/td>\n<\/tr>\n<tr>\n<th>7. Safety<\/th>\n<td>Interlocks, hydrogen peroxide detection, alarms, emergency stop, behaviour on power loss or fault.<\/td>\n<\/tr>\n<tr>\n<th>8. Interfaces<\/th>\n<td>HVAC, BMS, doors, power, compressed air, drainage, and who provides each one.<\/td>\n<\/tr>\n<tr>\n<th>9. Documentation and qualification<\/th>\n<td>Documents to be delivered, FAT and SAT, support for IQ, OQ and PQ.<\/td>\n<\/tr>\n<tr>\n<th>10. Service and training<\/th>\n<td>Training, spare parts, calibration, response time, warranty.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2>Example requirements you can adapt<\/h2>\n<p>Requirements should be numbered, testable and written one per line. The examples below are illustrations; replace the values with your own, based on your risk assessment and site limits.<\/p>\n<div style=\"overflow-x:auto\">\n<table>\n<thead>\n<tr>\n<th>No.<\/th>\n<th>Requirement<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th>URS-3.1<\/th>\n<td>The system shall be capable of a cycle that achieves a 6-log reduction of <em>Geobacillus stearothermophilus<\/em> biological indicators at all worst-case locations defined in PQ.<\/td>\n<\/tr>\n<tr>\n<th>URS-3.2<\/th>\n<td>The total cycle time, from start of dehumidification to release, shall not exceed [X] hours for the largest enclosure in Appendix A.<\/td>\n<\/tr>\n<tr>\n<th>URS-3.3<\/th>\n<td>The enclosure shall be released only when the hydrogen peroxide concentration measured by a low-range sensor is below [site limit] ppm.<\/td>\n<\/tr>\n<tr>\n<th>URS-4.1<\/th>\n<td>The supplier shall state the required start-of-cycle temperature and relative humidity, and the HVAC conditions needed to reach them.<\/td>\n<\/tr>\n<tr>\n<th>URS-5.1<\/th>\n<td>All wetted parts in contact with hydrogen peroxide liquid or vapor shall be compatible with it; the supplier shall list the materials.<\/td>\n<\/tr>\n<tr>\n<th>URS-5.2<\/th>\n<td>The system shall measure and record hydrogen peroxide concentration, temperature and relative humidity during the cycle.<\/td>\n<\/tr>\n<tr>\n<th>URS-6.1<\/th>\n<td>The control system shall provide at least three user levels and an audit trail of logins, recipe changes, alarms and cycle starts and stops.<\/td>\n<\/tr>\n<tr>\n<th>URS-6.2<\/th>\n<td>Cycle records shall be exportable in a format agreed with QA and shall support compliance with 21 CFR Part 11 and EU GMP Annex 11.<\/td>\n<\/tr>\n<tr>\n<th>URS-7.1<\/th>\n<td>Doors and access points to the enclosure shall be interlocked so that they cannot be opened during injection, hold or aeration.<\/td>\n<\/tr>\n<tr>\n<th>URS-8.1<\/th>\n<td>The supplier shall provide an interface list of all signals exchanged with the HVAC control system and BMS.<\/td>\n<\/tr>\n<tr>\n<th>URS-9.1<\/th>\n<td>A factory acceptance test shall be performed with the user&rsquo;s participation, to a protocol approved in advance.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2>Writing requirements that can be tested<\/h2>\n<p>A requirement is useful only if someone can later prove it was met. A few habits make a big difference:<\/p>\n<ul>\n<li><strong>Use &ldquo;shall&rdquo; for mandatory requirements<\/strong> and &ldquo;should&rdquo; for preferences, and say which is which in the introduction.<\/li>\n<li><strong>One requirement per line<\/strong>, with its own number, so it can be traced to a test.<\/li>\n<li><strong>Measurable wording.<\/strong> &ldquo;Fast aeration&rdquo; cannot be tested; &ldquo;release below [limit] ppm within [X] hours&rdquo; can.<\/li>\n<li><strong>State the need, not the design.<\/strong> Write what the system must achieve, and let suppliers propose how. Fix a design only where your site really requires it, for example a particular PLC brand.<\/li>\n<li><strong>Mark criticality.<\/strong> Identify which requirements are GMP-critical, so the validation team knows what must be tested in IQ, OQ and PQ.<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th>Weak requirement<\/th>\n<th>Testable requirement<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>The system shall sterilize the room.<\/td>\n<td>The system shall be capable of a cycle that achieves a 6-log reduction of <em>G. stearothermophilus<\/em> BIs at the worst-case locations defined in PQ.<\/td>\n<\/tr>\n<tr>\n<td>The system shall be easy to use.<\/td>\n<td>An operator shall be able to start a validated recipe from the HMI in no more than [N] steps, without changing parameters.<\/td>\n<\/tr>\n<tr>\n<td>The system shall be safe.<\/td>\n<td>Enclosure doors shall remain locked until the low-range sensor reads below [limit] ppm.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<figure>\n<img width=\"900\" height=\"675\" decoding=\"async\" src=\"\/wp-content\/uploads\/site\/cutout-vhp.jpg\" alt=\"HVAC-integrated VHP generator with rotary dehumidifier\" style=\"max-width:520px;margin:0 auto\"><figcaption>An HVAC-integrated VHP generator. Its URS must cover the HVAC and BMS interfaces as well as the generator itself.<\/figcaption><\/figure>\n<h2>Interfaces: the section most URS documents miss<\/h2>\n<p>For a room or HVAC-integrated system, most commissioning problems come from interfaces that were never assigned. Add a responsibility matrix to the URS, with one row per interface:<\/p>\n<ul>\n<li>HVAC dampers and fan modes for dehumidification, injection, hold and aeration.<\/li>\n<li>BMS signals: start permissive, cycle status, alarms, return to production mode.<\/li>\n<li>Door and pass box interlocks, and the safe state on a fault.<\/li>\n<li>Power, compressed air, drainage and exhaust connections.<\/li>\n<li>Location and routing of VHP piping, and insulation to avoid condensation.<\/li>\n<li>Hydrogen peroxide gas detection in occupied areas next to the enclosure.<\/li>\n<\/ul>\n<p>For each row, state who designs it, who supplies it, who installs it and who tests it. For the design side of these interfaces, see <a href=\"\/how-vhp-generator-works\/\">how a VHP generator integrates with cleanroom HVAC<\/a>.<\/p>\n<h2>Documentation and qualification requirements<\/h2>\n<p>Ask for the documents in the URS, not after the order. A typical list:<\/p>\n<ul>\n<li>Design or functional specification answering each URS line, with a traceability matrix.<\/li>\n<li>Layout drawings, P&amp;ID and electrical drawings.<\/li>\n<li>Material certificates for wetted parts and calibration certificates for sensors.<\/li>\n<li>FAT and SAT protocols and reports.<\/li>\n<li>IQ and OQ protocols, and support for cycle development and PQ.<\/li>\n<li>Operating and maintenance manuals, spare parts list and software version record.<\/li>\n<\/ul>\n<p>Cycle efficacy is proven in PQ, not by the supplier&rsquo;s datasheet. See <a href=\"\/vhp-cycle-development-qualification\/\">VHP cycle development and qualification<\/a> and <a href=\"\/vhp-validation-biological-indicators\/\">how a VHP cycle is validated<\/a>.<\/p>\n<h2>Common mistakes<\/h2>\n<ul>\n<li><strong>Copying a datasheet into the URS.<\/strong> It fixes one supplier&rsquo;s design and hides what you actually need.<\/li>\n<li><strong>Promising efficacy without saying how it is proven.<\/strong> &ldquo;6-log&rdquo; means nothing without biological indicators, locations and acceptance criteria.<\/li>\n<li><strong>Leaving aeration out of the cycle time.<\/strong> Aeration can take as long as the rest of the cycle and decides when production restarts.<\/li>\n<li><strong>Ignoring materials.<\/strong> Sealants, gaskets and electronics in the enclosure need to be listed and checked for compatibility.<\/li>\n<li><strong>No interface matrix.<\/strong> The most common cause of delays at commissioning.<\/li>\n<li><strong>Writing the URS after the supplier is chosen.<\/strong> Then it describes the purchase instead of the need.<\/li>\n<\/ul>\n<h2>How Fenggu works with a URS<\/h2>\n<p>Fenggu manufactures <a href=\"\/products\/hvac-integrated-vhp-system\/\">HVAC-integrated VHP systems<\/a>, <a href=\"\/products\/mobile-vhp-room-sterilizer\/\">mobile room sterilizers<\/a>, generators for equipment interiors, VHP pass boxes, airlocks and a VHP BIBO sterilizer. Send your URS, drawings and room list, and our engineers will review it and propose a configuration, with questions on any requirement that needs clarification.<\/p>\n<p>All VHP equipment: <a href=\"\/products\/vhp-sterilization-equipment\/\">VHP sterilizers and generators<\/a>.<\/p>\n<p class=\"fg-xlink\"><strong>Free download:<\/strong> <a href=\"https:\/\/fgvhp.com\/resources\/isolator-urs-template\/\" target=\"_blank\" rel=\"noopener\">Isolator URS Template (Word)<\/a> &mdash; 57 example requirements, including VHP decontamination and leak tightness.<\/p>\n<h2>FAQ<\/h2>\n<p><strong>What is a URS for a VHP system?<\/strong><br \/>It is the user requirement specification: the document in which the user defines what the VHP decontamination system must do, in which enclosures, under which conditions, with which documents. Suppliers answer it, and qualification tests are traced back to it.<\/p>\n<p><strong>Who should write the VHP URS?<\/strong><br \/>The user, usually engineering together with QA, validation, production and EHS. Suppliers can comment on it, but the requirements should come from the user&rsquo;s needs and risk assessment.<\/p>\n<p><strong>Should the URS specify concentration and cycle parameters?<\/strong><br \/>Usually not as fixed values. Specify the performance you need and how it will be demonstrated; the cycle parameters are set during cycle development and confirmed in PQ.<\/p>\n<p><strong>How long should a VHP URS be?<\/strong><br \/>Long enough to cover the sections above with testable requirements. For a single mobile unit a few pages may be enough; an HVAC-integrated system for a multi-room suite needs more, mainly because of interfaces.<\/p>\n<p><strong>Can one URS cover several VHP applications?<\/strong><br \/>Yes, if each enclosure and scenario is listed separately in the enclosures section, with its own performance and interface requirements.<\/p>\n<h2>References<\/h2>\n<ul>\n<li>ISPE Baseline Guide Volume 5: Commissioning and Qualification (2nd edition, 2019)<\/li>\n<li>ISPE GAMP 5: A Risk-Based Approach to Compliant GxP Computerized Systems (2nd edition, 2022)<\/li>\n<li>EU GMP Annex 15: Qualification and Validation (2015)<\/li>\n<li>EU GMP Annex 1: Manufacture of Sterile Medicinal Products (2022)<\/li>\n<li>EU GMP Annex 11: Computerised Systems<\/li>\n<li>FDA 21 CFR Part 11, Electronic Records; Electronic Signatures<\/li>\n<\/ul>\n<div class=\"fg-cta\">\n<h3>Writing a VHP URS?<\/h3>\n<p>Send your draft URS, layout and room list. Our engineers will review it and propose a configuration.<\/p>\n<p><a class=\"fg-btn\" href=\"\/products\/vhp-sterilization-equipment\/\">View VHP Equipment<\/a><br \/>\n<a class=\"fg-btn o\" href=\"\/contact\/\">Request a Quote<\/a>\n<\/div>\n<\/article>\n","protected":false},"excerpt":{"rendered":"<p>VHP Sterilization &middot; Buyer&rsquo;s Guide How to Write a URS for a VHP Decontamination System Fenggu Pharmaceutical Equipment &middot; VHP [&hellip;]<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[1],"tags":[],"class_list":["post-494","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/posts\/494","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/comments?post=494"}],"version-history":[{"count":1,"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/posts\/494\/revisions"}],"predecessor-version":[{"id":497,"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/posts\/494\/revisions\/497"}],"wp:attachment":[{"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/media?parent=494"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/categories?post=494"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fenggu-bio.com\/pt\/wp-json\/wp\/v2\/tags?post=494"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}