From contamination risk to the right cleanroom decision.

Clear contamination risk insights for contamination-critical products.

View example analysis Run your own simulation

We use validated contamination models, not intuition, to assess risk and recommend cleanroom requirements.

Used in contamination sensitive product environments

Built for cleanroom professionals

Designed for professionals working with contamination-sensitive products in controlled environments:

Product and process developers
Quality engineers
Cleanroom managers
Production supervisors
Process engineers

To set and evaluate cleanliness requirements

From product specs to air cleanliness (cleanroom) requirements

Translate your product's contamination sensitivity into actionable cleanroom specifications. Based on ISO 14644 cleanroom standards.

The calculator determines for given vulnerabilities:

Maximum allowable particle deposition rates
Required local air cleanliness expressed as cleanroom class
Monitoring alarm limits

Three calculators in one

Choose the calculator that fits your situation:

Product Sensitivity: Discover air cleanliness and particle deposition rate requirement for various product contamination inputs
Cleanroom Capability: Evaluate the estimated performance of your current cleanroom setup
Monitoring Setup: Configure alarm thresholds for particle deposition sensors or measurement methods

Learn About Particle Deposition

Background theory, formulas, and detailed explanations

Product contamination calculator

Enter your product specifications to assess contamination risk

Product Name (optional)

Small critical particles

Small Critical Particle Size (μm)

Smallest critical particle size (≥5 μm typical)

Max Acceptable Number

0.1 or more particles acceptable per product (decimals allowed)

Improve risk accuracy (optional)

Add production data to increase confidence in your contamination assessment.

Large Critical Particle Size (μm)

Providing this information refines the precision of your risk estimate. You can complete the simulation without it.

Product specifications

Vulnerable Product Area

Vulnerable surface area that must stay clean

Area Unit

Time of Exposure

Time surface is exposed during operations (not at-rest)

Time Unit

How it works

1. Define particle vulnerabilities

Critical particle size derived from the smallest circle around particle silhouette under microscope. Consider impact on product functionality.

2. Calculate deposition rate limits

R_D = N_D/(A·T) number of particles ≥ D μm per m² per hour.

N_D is maximum acceptable number of particles on product
A is vulnerable product area
T is time of exposure of vulnerable product surface

Max acceptable number: If only a part of the products may have one particle, then give the number in steps of 0.1. For example: 1 particle per 5 products = 0.2

3. Assess contamination risk

Get Particle Deposition Rate Level L and particle number limit per sample (event limit)

Learn more

Cleanroom calculator

Calculate expected cleanroom performance and ISO classification

Cleanroom specifications

Cleanroom Area

Cleanroom Height

Air Supply

Ventilation Efficiency

Personnel parameters

Garment Level

Maximum Personnel

Activity Level

Process location (optional)

Include Process Location Analysis

Changing room (optional)

Include Changing Room

How it works

1. Air Cleanliness Level

C₅ = S₅ ε · Q + C_{5 at rest} particles ≥ 5 μm per m³
In this calculation C_{5 at rest} is neglected

2. Personnel Source Strength

S₅ = activity level × average emission at low activity

Average emission depends on garment selection (Table)

3. Ventilation Efficiency

ε determines mixing efficiency: 0.5 (poor), 0.7 (typical), ≥1.0 (good ventilation)

4. Cleanroom ISO class

Classification based on particle concentration levels

At Process Location:

5. Particle deposition Rate Level

Empirical relation: air removable particles ≤ 40 μm

Learn more

Particle deposition monitoring

Configure monitoring parameters and calculate event limits

Product parameters

Small Critical Particle Size (μm)

Smallest critical particle size (≥10 μm typical)

Max acceptable number

0.1 or more particles acceptable per product

Vulnerable product area

Area Unit

Time of Exposure

Time Unit

Monitoring method

Select monitoring method

Choose a predefined monitoring method or configure custom parameters

Sample configuration

Sample Time

Sample Time Unit

Sample Area

Sample Area Unit

How it works

1. What is an event limit?

The event limit is the maximum number of particles allowed in a single sample to stay within acceptable deposition rates.

2. Monitoring methods

APMON II: Continuous monitoring with 50 cm² surface, 4-minute intervals

Witness Plate: Passive monitoring with 64 cm² surface, typically 4-hour exposure

Learn more

Overview

Products or processes that can be harmed by particle contamination need contamination control measures. A vulnerable product possesses one or more vulnerable surfaces that are important for its functionality.

Major Contamination Mechanisms

Deposition of particles from the air onto vulnerable surfaces
Transfer of particles from another surface during contact
Contamination of potential contact surfaces by particle deposition

Surface Cleanliness Requirements

When there is a surface cleanliness requirement, the maximum acceptable number of particles is determined by the difference between final surface cleanliness and initial surface cleanliness.

About INSIGHTS: This is a trial-and-error module that offers insight into the required particle deposition rate limit for a product or process, the require air cleanliness and the capability of a potential cleanroom.

Particle Deposition Process

Particle deposition is the deposition of particles from the air onto surfaces. Before deposition, these particles were in the air.

Physical Forces at Play:

Gravitation: Causes downward movement depending on particle mass
Shape resistance: Cross-section area perpendicular to movement direction opposes gravitational forces
Sedimentation velocity: Net result calculated by Stokes law (with corrections for submicron and visible particles ≥75 µm)
Turbulence: Can add momentum to particles
Air movement: Influences particle trajectory

Particle Settling

Particles settle due to gravity, opposed by shape resistance

Residence Time Factor: When the residence time of surrounding air pockets in a room is smaller than the time to deposit, particles will most likely not deposit unless the air pocket strikes a surface or passes an electrostatically charged surface before leaving the room.

Surface Contamination Factors

The likelihood of contamination depends on:

Particle deposition rate
Area of the vulnerable surface
Time of exposure of the vulnerable surface

Contamination Control Principles

To control deposition of unwanted particles, both exposure time and particle deposition rate should be limited.

Particle Deposition Rate Factors

Cleanliness of air supplied to the room
Air volume supply rate
Ventilation efficiency
Effective air change rate
Personnel emissions (garments, behavior, activities)
Equipment emissions
Work procedures
Cleaning program and surface cleanliness

Critical Considerations

Particle size that is not accepted should ideally be zero, but this leads to unrealistic rates
Look for the largest particle size that can sometimes be accepted
Select a second particle size accepted in low numbers
Expected average time of exposure in hours

Effective Air Change Rate Formula:

Effective ACR = Ventilation Efficiency × Air Supply (m³/h) / Room Volume

Cleanroom Design Principles

The air volume supply rate to a cleanroom determines the air cleanliness level for a given source strength. Clean air dilutes particle concentration, with dilution depending on ventilation efficiency.

Key Design Factors:

Air Flow: Carries airborne particles out of the cleanroom
Air Change Rate: Air volume supply rate divided by room volume
Ventilation Efficiency: Determines average residence time of supplied air
Residence Time: Determines whether particles can deposit

Clean Air Supply

HEPA filtered air dilutes particle concentration

Personnel Source Strength

Garment Type	≥0.5 µm	≥5 µm	≥50 µm
Street clothes	5,000,000	500,000	50,000
Cleanroom smock + covers	2,000,000	100,000	5,000
Coverall	250,000	5,000	50
Full cleanroom suit	150,000	2,500	10
Undergarments + full suit	50,000	1,000	2

*Particles per minute with low activity. Multiply by 2, 3, or 4 for medium, high, or extreme activity levels.

Ventilation Efficiency Values:

Bad ventilated cleanroom: ε = 0.5
Most non-unidirectional cleanrooms: ε = 0.7
Good cleanroom: ε ≥ 1.0

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From contamination risk to the right cleanroom decision.

Built for cleanroom professionals

From product specs to air cleanliness (cleanroom) requirements

Three calculators in one

Product contamination calculator

Small critical particles

Improve risk accuracy (optional)

Product specifications

Calculation results

How it works

1. Define particle vulnerabilities

2. Calculate deposition rate limits

3. Assess contamination risk

Cleanroom calculator

Cleanroom specifications

Personnel parameters

Process location (optional)

Changing room (optional)

Cleanroom results

How it works

1. Air Cleanliness Level

2. Personnel Source Strength

3. Ventilation Efficiency

4. Cleanroom ISO class

At Process Location:

5. Particle deposition Rate Level

Particle deposition monitoring

Product parameters

Monitoring method

Sample configuration

Monitoring results

How it works

1. What is an event limit?

2. Monitoring methods

Major Contamination Mechanisms

Surface Cleanliness Requirements

Particle Settling

Particle Deposition Rate Factors

Critical Considerations

Clean Air Supply

From contamination risk to the right cleanroom decision.

Built for cleanroom professionals

From product specs to air cleanliness (cleanroom) requirements

Three calculators in one

Product contamination calculator

Small critical particles

Improve risk accuracy (optional)

Product specifications

Calculation results

How it works

1. Define particle vulnerabilities

2. Calculate deposition rate limits

3. Assess contamination risk

Cleanroom calculator

Cleanroom specifications

Personnel parameters

Process location (optional)

Changing room (optional)

Cleanroom results

How it works

1. Air Cleanliness Level

2. Personnel Source Strength

3. Ventilation Efficiency

4. Cleanroom ISO class

At Process Location:

5. Particle deposition Rate Level

Particle deposition monitoring

Product parameters

Monitoring method

Sample configuration

Monitoring results

How it works

1. What is an event limit?

2. Monitoring methods

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