VHP bio-decontamination glossary

Core concepts 核心概念

Biodecontamination / Bio-decontamination生物除污染

Reducing viable microorganisms on the exposed surfaces of a room, enclosure or piece of equipment to a defined level — for VHP usually demonstrated as a 6-log reduction of bacterial spores on biological indicators. It treats surfaces, not the inside of products.

Decontamination净化 / 去污

Removing or inactivating contaminants — microbial, chemical or particulate — so an item or area is safe for its next use. A broader term than biodecontamination.

Vaporized Hydrogen Peroxide (VHP)汽化过氧化氢（VHP）

Hydrogen peroxide solution, typically 30–35% w/w, flash-vaporized and delivered into a sealed space as a low-temperature, sporicidal vapour. What VHP decontamination is →

Hydrogen peroxide vapour过氧化氢蒸汽

The gaseous hydrogen peroxide, together with water vapour, that a VHP generator produces. It is the active agent in contact with surfaces during the cycle.

Cold sterilization低温灭菌

Sterilization or decontamination at or near room temperature, without the heat of steam or dry-heat processes. Suitable for heat-sensitive materials, plastics and electronics.

Sterilant灭菌剂

An agent able to kill all forms of microbial life, including bacterial spores. In a VHP process the sterilant is the hydrogen peroxide solution.

Antimicrobial (broad-spectrum)（广谱）抗菌剂

Effective against a wide range of organisms — bacteria, fungi, viruses and bacterial spores — rather than a single group.

Sporicidal杀芽孢的

Able to kill bacterial spores, the most resistant form of microbial life. EU GMP Annex 1 expects a sporicidal agent in the cleanroom disinfection programme.

Residue-free无残留

Hydrogen peroxide breaks down into water and oxygen, so surfaces do not need to be wiped down after the cycle — a key advantage over formaldehyde.

Saturation / dew point饱和 / 露点

The point at which air cannot hold more vapour; beyond it, vapour condenses on surfaces. Cycle design controls humidity and concentration relative to this point. VHP concentration, humidity and condensation →

Enclosure / Chamber密闭空间 / 腔体

The sealed volume being treated — a room, isolator, pass box, filter housing or the chamber of a piece of equipment.

Cycle phases 循环阶段

Dehumidification除湿

Phase 1. The relative humidity in the enclosure is lowered so that more hydrogen peroxide can be held as vapour without condensing.

Conditioning调节

Phase 2. Vapour is injected at a high rate to bring the concentration up to the target quickly and evenly.

Decontamination / Sterilization (phase)灭菌

Phase 3. The concentration is held for the validated dwell time, during which microorganisms on exposed surfaces are inactivated.

Aeration通气

Phase 4. The vapour is removed — catalytically, by exhaust, or both — until the concentration is below the release limit, often 1 ppm. VHP aeration time calculator →

Systems and components 系统与部件

Closed-loop / open-loop封闭环路 / 开放式环路

In a closed loop, air from the enclosure passes through the generator and returns to it. In an open loop, fresh air is drawn in and the treated air is exhausted.

Recirculating system再循环系统

A generator that forms a closed loop with an enclosure or piece of equipment through supply and return connections.

Catalytic converter催化转化器

An element that breaks hydrogen peroxide down into water and oxygen, used to shorten aeration and to make exhaust air safe.

Flash vaporization闪蒸

Injecting the liquid onto a hot surface so it vaporizes instantly and completely, keeping the peroxide-to-water ratio of the solution in the vapour. How a VHP generator works →

VHP generatorVHP 发生器

The equipment that dehumidifies, vaporizes and injects hydrogen peroxide, monitors concentration, humidity and temperature, and controls the cycle.

Skid撬块 / 模块

Equipment pre-assembled on a frame and delivered as a single module, ready to connect to site utilities.

Manifold分配管汇 / 多支管

Distribution piping that splits the vapour flow between several outlets or rooms.

Balancing damper平衡风阀

A damper set to balance airflow between branches of a duct system, so each room receives its share of vapour.

Ductwork管道 / 风管系统

The air distribution ducts. In HVAC-integrated VHP the ducts carry the vapour, so their materials and leak-tightness matter.

HEPA filter / pre-filter高效过滤器（HEPA）/ 预过滤器

High-efficiency particulate air filter (for example H13 or H14 under EN 1822); the pre-filter upstream protects it from coarse dust.

AHU (Air Handling Unit)空气处理机组（AHU）

The unit that conditions, filters and moves air for a cleanroom suite. An HVAC-integrated VHP system distributes vapour through it.

HVAC暖通空调（HVAC）

Heating, ventilation and air conditioning — the building systems that control temperature, humidity, pressure and air changes.

Desiccant dehumidifier转轮除湿机

A dehumidifier using a rotating desiccant wheel to remove moisture, able to reach low humidity faster than cooling alone.

Air exchange换气次数

How many times the air volume of a space is replaced per hour. It governs how fast vapour is diluted during aeration.

Injection rate注入速率

The mass of hydrogen peroxide solution vaporized per minute, usually in g/min.

Operator interface / touch panel操作界面 / 触摸屏

The screen used to start cycles, select recipes, view live values and review records.

Interlocked doors互锁门

Doors that cannot be opened at the same time, so air and contamination cannot pass straight through. Cleanroom airlock types →

Double gasket door双密封门

A door sealed by two gaskets for better leak-tightness, used where vapour or containment must not escape.

Pass-through hatch / pass box传递窗 / 传递舱

A small chamber with interlocked doors in a cleanroom wall for transferring materials; a VHP pass box also decontaminates their outer surfaces. VHP pass box guide →

Diffuser / nozzle扩散器 / 喷嘴

The outlet that releases vapour into the space and helps distribute it.

PLC / SCADAPLC / SCADA

Programmable logic controller and supervisory control and data acquisition — the control and data systems of the equipment and plant.

Efficacy and microbiology 灭菌效力与微生物

6-log reduction降低 6 个对数级（99.9999%）

A reduction of the viable count by a factor of one million, usually shown on biological indicators carrying at least 10⁶ spores. Biological indicators and the 6-log reduction →

SAL 10⁻⁶ (Sterility Assurance Level)无菌保证水平 SAL 10⁻⁶

A probability of no more than one non-sterile item in a million after sterilization. It applies to terminally sterilized products; surface biodecontamination is normally specified as a log reduction.

Log reduction对数级下降

The reduction in viable microorganisms expressed in powers of ten: 1-log is 90%, 3-log is 99.9%, 6-log is 99.9999%.

Biological Indicator (BI)生物指示剂

A carrier inoculated with a known population of resistant spores. Growth or no growth after incubation shows whether the cycle reached that location.

Chemical Indicator (CI)化学指示剂

An indicator that changes colour on exposure to hydrogen peroxide. It shows that vapour reached a location, not that microorganisms were killed.

Geobacillus stearothermophilus嗜热脂肪地芽孢杆菌

A spore-forming bacterium highly resistant to hydrogen peroxide, used as the standard test organism in VHP biological indicators.

Bacterial spores细菌芽孢

The dormant, highly resistant form of some bacteria. Killing spores is the benchmark for a sporicidal process.

Settle plate沉降菌平皿

An open agar plate exposed for a set time to collect microorganisms settling from the air.

Contact plate接触碟

An agar plate pressed onto a flat surface to sample the microorganisms on it.

Glove print手套印

Fingertips of a glove pressed onto agar to monitor glove contamination after aseptic operations. Isolator glove integrity testing →

cfu (colony-forming unit)菌落形成单位（CFU）

A unit for counting viable microorganisms: each colony on an agar plate is assumed to come from one viable unit.

GMP and validation GMP与验证

EU GMP Annex 1欧盟 GMP 附录1

The EU guideline for the manufacture of sterile medicinal products, revised in 2022, which sets expectations for contamination control, cleanrooms and barrier systems. EU GMP Annex 1 overview →

Grade A / B / C / DA / B / C / D 级

EU GMP cleanroom grades. Grade A is the critical zone for aseptic operations; B is its background for open processing; C and D are for less critical stages.

Validation / validatable验证 / 可验证

Documented evidence that a process consistently produces the intended result. A validatable cycle is reproducible and measurable enough to be proven.

IQ / OQ / PQ安装确认 / 运行确认 / 性能确认

Installation, operational and performance qualification: confirming the equipment is installed correctly, operates as specified, and performs reliably in real use. VHP cycle development and IQ/OQ/PQ →

FAT / SAT工厂验收测试 / 现场验收测试

Factory and site acceptance tests: checking the equipment against the specification before shipment and again after installation. Isolator FAT and SAT checklist →

P&ID管道及仪表图（P&ID）

Piping and instrumentation diagram: the drawing of process lines, valves, instruments and control connections.

Thermocouple probe热电偶探头

A temperature sensor used to map temperature in the enclosure during cycle development and qualification.

Cycle development循环开发

The work of setting cycle parameters for a specific enclosure and load, and confirming them with indicators, before qualification.

Load / load configuration负载 / 装载方式

What is inside the enclosure during the cycle, and how it is arranged. A change in load can change the cycle result.

URS / FS / DQ用户需求说明 / 功能说明 / 设计确认

User requirement specification, functional specification and design qualification — the documents that define what is needed and confirm the design meets it.

Utility requirements公用工程要求

The services the equipment needs on site, such as power, compressed air, exhaust and network connections.

Scope of supply / work供货范围 / 工作范围

What the supplier delivers and what work it performs, as distinct from what the customer provides.

Relative humidity (RH)相对湿度

The water vapour in air as a percentage of the maximum it could hold at that temperature. It limits how much peroxide vapour the air can carry.

Material compatibility材料兼容性

Whether materials tolerate repeated exposure to hydrogen peroxide, and whether they absorb it and slow aeration. VHP material compatibility →

Applications 应用场景

Aseptic filling无菌灌装

Filling sterile product into sterile containers in a Grade A environment, often inside an isolator. Hydrogen peroxide uptake in isolator filling →

Sterility testing无菌检查

The pharmacopoeial test for sterility of finished product, usually performed in an isolator to avoid false positives.

Biological Safety Cabinet (BSC)生物安全柜

A ventilated cabinet that protects the operator, the product and the environment when handling biological agents.

BSL-3 / BSL-4生物安全 3 级 / 4 级

Biosafety levels for laboratories handling serious or life-threatening agents, with sealed rooms that are decontaminated as a whole.

Material transfer物料传递

Moving materials into or out of a controlled area without bringing contamination with them — by pass box, airlock or transfer port. VHP equipment selector →