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Compressed Air Testing Pharmaceutical Manufacturing

Compressed air serves a crucial role in manufacturing. Considered the fourth utility, alongside water, electricity, and gas, compressed air powers vital equipment, control valves, and packaging lines.

According to the Department of Energy, over 70% of all manufacturing businesses in the US use compressed air in their production.

In the pharmaceutical and medical instrument sector, pneumatic-powered systems assist with product handling and may come into direct contact with the products.

Because of this close interaction, strict standards have been established to ensure compressed air remains free from harmful contaminants. All manufacturers are expected to meet these regulatory requirements.

Here’s everything you need to know about compressed air testing for pharmaceutical manufacturing processes.

What Is Compressed Air Testing in Pharmaceutical Manufacturing?

Compressed air testing is a standardized process in which technicians from accredited laboratories analyze the purity of air being used in manufacturing. These evaluations are generally required for facilities that produce products that may impact product quality and human health.

In the pharmaceutical sector, compressed air is generally tested for oil, particulates, microorganisms, toxic gases, and moisture to ensure they remain at safe, acceptable levels.

This is because pneumatic systems in these facilities are often involved in formulation and packaging. Impurities in these stages can adversely affect sensitive equipment and the end product. Even the smallest trace of contaminants can raise serious compliance breaches and legal consequences. Not to mention costly system failures.

Regular air testing helps identify contamination risks and prevent them from turning into a major headache.

Why Is Compressed Air Purity Critical in Pharma Facilities?

Pharma facilities may rely on compressed air for various production processes, including tablet coating and drying, filling and packaging, and end product conveying.

Because most of the items they produce are consumed, injected, or applied directly to the human body, maintaining clean, high-quality compressed air is essential to protect drug integrity and consumer health.

Microbial, Moisture, and Oil Contamination Risks

Oil contamination is a common issue in many production facilities. These issues often occur when compressor lubricants leak due to improper maintenance and invade other systems.

If left alone, oil aerosols harm nearby equipment, impact product quality, and compromise consumer safety.

Moisture is similarly prevalent and problematic. 

Without sufficient air dryers, vapor can accumulate in piping systems, creating conditions for microorganisms to thrive. Bacteria, viruses, and fungi may reach sensitive production areas, posing health hazards.

Particulate Matter and Drug Quality Risks

In addition to oil and moisture, particulate impurities can just as easily enter pneumatic systems without proper safeguards.

Cytotoxic dust, dirt, and rust from corrosion can endanger workers and degrade the quality of compressed air.

Moreover, air containing these impurities can result in cross-contamination, with airborne dust migrating between systems and ruining batches of pharma products.

The International Organization for Standardization (ISO) imposes rigid standards for the acceptable number and size of permissible airborne particulates in pharmaceutical environments.

Frequent testing validates compliance with relevant regulations and that filtration systems are working as intended.

Compressed Air Standards for Pharmaceutical Manufacturing

Facilities that produce drugs and medical instruments follow strict guidelines mandated by several local and international regulatory bodies.

ISO 8573 Purity Standards

The ISO 8537 series is an internationally accepted standard in compressed air analysis in various industries, including pharma firms. 

ISO 8537 1 provides guidelines and classifies purity levels for major contaminants, namely:

  • Water or moisture
  • Oil and hydrocarbon
  • Gaseous impurities
  • Microbial content
  • Solid particulates 

 

Different classes of ISO purity standards may apply to different stages of production. But they generally require low oil concentrations, strict particulate control, and low dew points.

Due to the nature of their products, pharmaceutical manufacturers must target higher levels of purity in their pneumatic systems. Even higher (Class 0) if compressed air is utilized closely with drug production.

The ISO 8537 also recommends practical methodologies for testing air quality for specific contaminants.

USP and cGMP Compliance Requirements

In the US, pharmaceutical manufacturers must comply with the requirements set by the United States Pharmacopeia (USP) for quality assurance.

Additionally, companies must follow the current Good Manufacturing Practice (cGMP).

USP guidelines focus on preventing contamination and environmental control. cGMP also places a high emphasis on quality compressed air and considers it a critical utility that should be closely monitored.

Companies in the drug production sector are expected to conduct risk assessments, validate compressed air systems, perform routine checks, and keep written records, among others.

FDA Expectations for Compressed Air Systems

Besides the USP, the US Food and Drug Administration (FDA) directs pharmaceutical firms to maintain compliant pneumatic systems.

During FDA inspections, inspectors may look for evidence that facilities are aware of where compressed air contacts with products and can identify risks.

Filtration and drying systems may be checked. Moreover, they may demand documentation for routine maintenance, validation, and air quality testing activities.

What Pharmaceutical Compressed Air Testing Includes

Depending on the type of contaminant, accredited laboratories have several testing instruments and methodologies.

Moisture and Dew Point Testing

Moisture and dew point testing are key steps in verifying air purity. 

Measuring the moisture levels gives you an idea of the amount of vapor inside compressed air systems. Dew point testing, on the other hand, determines the temperature at which vapor condenses into water.

To do these tests, technicians primarily use hygrometers, spectroscopy, and detection cubes. 

If the moisture content and dew point values exceed acceptable levels, the experts may recommend installing desiccant and membrane dryers.

Oil Mist and Hydrocarbon Detection

The second part of the ISO 8537 details how to measure oil aerosols and hydrocarbons in compressed air systems.

Air samples are passed through specialized membranes to capture oil residues. Infrared spectrometry is then used to determine the severity of oil contamination.

Particulate and Particle Count Analysis

Specialists test whether the particulate count and size in pneumatic systems remain compliant with ISO and USP standards. They do this using a laser particle counter or microscopic filter collection.

Microscopic filtering is more labor-intensive and requires special membranes to detect particulates. Laser counters are automated and ideal for rapid analysis.

Microbial and Toxic Gas Testing

This test evaluates whether bacteria, viruses, fungi, yeast, molds, and other microorganisms are present in compressed air.

To find out, technicians take a sample of compressed air near a point of use, often using agar plates. The sample is then incubated in a laboratory for microbiological testing.

Some facilities may also be required to conduct toxic gas testing to detect traces of hazardous gases, such as carbon monoxide and sulfur dioxide.

Pressure and Flow Rate Verification

Too much or insufficient compressed air flow can lead to systems lagging and, worse, failing.

Air pressure (PSI) and flow rate (CFM) are vital testing metrics for detecting leaks and ensuring pneumatic devices are in optimal condition. Routine checks of these parameters may help prolong equipment life.

How Compressed Air Validation Is Performed

Validation is a key part of compliance in the pharmaceutical sector, proving that compressed air systems are clean and functioning within the set standards.

Installation and Operational Qualification

Under ISO 8573, validating air purity for pharma companies usually begins with installation qualification (IQ) and operational qualification (OQ).

IQ verifies that the compressed air system physically matches design specifications, while OQ confirms that everything, from the pipes to the dryers, filters, and compressors, is operating as it should.

Performance Qualification and Revalidation

The quality of compressed air is evaluated during performance qualification (PQ). During testing, the pneumatic system must demonstrate consistent performance in real manufacturing scenarios.

Pharmaceutical companies should also revalidate results through routine checks and prove continued compliance.

Compressed Air Compliance and Testing Frequency

Monitoring and testing compressed air quality must be performed routinely. How often you’ll need to test for compliance can vary by industry.

How Often Pharmaceutical Facilities Should Test

Due to the stringent safety regulations for pharmaceutical facilities, testing should be performed more frequently than in other manufacturers.

While neither the ISO, USP, nor the FDA mandates a specific number, it may be a good idea to conduct compressed air testing semi-annually or quarterly.

What Happens When Systems Fail Compliance

Failing a compressed air quality test can lead to batch product rejections and regulatory sanctions. In the worst case, some facilities may damage their reputation and be forced to halt production.

Choosing a Compressed Air Testing Provider

When choosing a compressed air testing provider, it’s important to consider whether they have the right accreditation and credentials. 

Confirm that their testing methods strictly follow USP, FDA, cGMP, and ISO requirements. You also want to make sure they have the testing expertise for your specific industry.

Why Choose Class 1 Air

Class 1 Air delivers reliable compressed air testing in the Midwest. The company is one of the largest providers of quality certification, validation, compliance, and repair services for compressed air systems in the region.

Accredited and Certified Field Service Experts

Our team of licensed field technicians is trained and certified by NSF/ANSI 49 and CETA CNBT-RCCP-SCF, guaranteeing the highest quality of services. Our team also closely collaborates with CETA, NEBB, IEST, NIH, and the CDC.

For reliable testing services, reach out to Class 1 Air today!

Table of Contents

Frequently Asked Questions

Compressed air quality testing is the process of sampling and analyzing compressed air at the point of use to measure levels of contamination including solid particles, moisture, oil and hydrocarbons, and viable microorganisms. Because compressed air is drawn from the surrounding environment and passes through compressors, piping, filters, and dryers before reaching its end use, it can carry a range of contaminants that pose risks to product quality, equipment performance, and regulatory compliance. Testing provides documented, quantified results that confirm whether your system meets the purity standards required by your industry.

ISO 8573 testing measures the three primary categories of contamination in compressed air: solid particulates, water and moisture, and oil including hydrocarbons. Each contaminant category is assessed against a numbered purity class, ranging from Class 0 (the strictest) to Class 9 (the most permissive), so facilities can verify their air quality against the specific classification their application requires. Some versions of the standard also address microbiological contamination, which is particularly relevant for pharmaceutical, food, and healthcare environments.


If your facility uses compressed air that comes into direct or indirect contact with drug products, medical devices, or food and beverage products, then yes, demonstrating compressed air quality is an expectation of FDA cGMP regulations. While the FDA does not prescribe a specific testing frequency, compressed air is considered a critical utility under quality system regulations, and the expectation is that it is validated, monitored, and documented as part of your overall quality program. ISO 8573 is the most widely accepted standard used to satisfy that requirement.

Clean Dry Air, or CDA, is a grade of compressed air that has been processed to remove virtually all moisture, particles, and hydrocarbons, typically to very stringent purity levels. It is most commonly used in semiconductor fabrication, electronics manufacturing, and aerospace applications where even trace contamination can damage sensitive components or compromise precision processes. CDA testing verifies that your air supply meets the ultra-clean specifications these industries require, often going beyond standard ISO 8573 classes to application-specific limits.

The on-site sampling portion of a compressed air test typically takes a few hours depending on the number of sample points, the tests being performed, and the size and complexity of your compressed air system. Particle count and dew point results can often be read immediately on-site, while microbial and hydrocarbon samples are sent to a laboratory for analysis. A full written report covering all test parameters is typically delivered within a few days of the site visit.

If your compressed air does not meet the required purity class, Class 1 Air will identify which contaminant or contaminants are out of specification and advise on the likely source of the problem, whether that is a failing filter, a compromised dryer, a contaminated distribution line, or another system issue. From there, corrective action can be taken and the affected sample points retested to confirm the system has been brought back into compliance. Catching a failure through routine testing is far preferable to discovering it through a product recall, a regulatory finding, or a contamination incident on the production floor.

Testing frequency depends on your industry, the regulatory framework your facility operates under, and how critical compressed air is to your process. For most regulated industries, annual testing is the baseline expectation. Pharmaceutical and medical device manufacturers typically test as part of a formal validation cycle, with requalification required any time a significant change is made to the compressed air system, such as a new compressor, filter replacement, or changes to distribution piping. Food and beverage facilities operating under SQF or HACCP programs are generally expected to test at least annually, with some certification bodies requiring more frequent monitoring at direct product contact points. Beyond scheduled testing, compressed air should also be tested following any contamination event, after corrective maintenance, or when product quality issues arise that could be attributed to air quality. Class 1 Air can work with your quality team to establish a testing schedule that meets your regulatory obligations and gives you year-round confidence in your compressed air system.

Our Locations

We are a regional service provider

We have offices in Milwaukee, Madison, and Chicago to serve your needs across the midwest. Class 1 Air is your single source company for air filtration products and critical environment compliance testing. We proudly serve the upper Midwest. Our company is committed to leadership throughout Wisconsin and the Midwest in biological safety.

We primarily service the below states:

Wisconsin
Milwaukee
Madison
Green Bay

Illinois
Chicago
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Indiana
Lafayette
South Bend 
Haute
Indianapolis
Fort Wayne
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Michigan
Detroit
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Warren

We also service these additional states through our sister companies at the Scientific Safety Alliance:

Minnesota

Iowa

Missouri

Kansas

Nebraska

Virginia

West Virginia

North Carolina

Washington dc

maryland

south carolina

kentucky

tennessee

north dakota

south dakota

wyoming

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