SQF Air PurityIn 2012, Safe Quality Food (SQF) requirements began including compressed air purity testing for the food production and packaging processes. The SQF Code states that compressed air “shall be regularly monitored for purity.” When asked for more detail about air purity testing, SQF went on to say the following, “Food processing facilities need to operate from a fundamental assumption that compressed air can be a source of chemical and microbiological contamination. Food facilities must verify and validate the compressed air used in their facility is appropriate for use and not a source of contamination.” Click here to read more on air purity testing from SQF. Although compressed air purity testing is not new to the food industry, this is the first certification group that made it a requirement in the United States. Compressed air contamination can occur in numerous ways, and if undetected can contaminate your final product. SQF auditors are asking for test results that address particles, water, oil, and microbial levels for the new SQF air purity requirement. Common breathing air specifications do not fully address the needs for compressed air purity used in manufacturing. Breathing air specifications do not address particles by size, microbial contaminants, and typically allow a much higher level of hydrocarbons (oil aerosol and vapor) than is considered safe for food production. Breathing air specifications focus on gases such as oxygen, carbon monoxide, and carbon dioxide that are not problematic for food processing. ISO 8573 is a compressed air specification often used in the food industry that addresses the testing for particles, water, oil and microbial contaminants in compressed air. SQF has not established acceptable limits for air purity. The following purity limits are from the BCAS (British Compressed Air Society) Food and Beverage Grade Compressed Air Best Practice Guideline 102, revised in 2013.
SQF Air Purity Compressed Air & Gas Testing SpecificationsTrace Analytics, LLC is an A2LA Accredited Laboratory in compliance with ISO 17025 as required by SQF Code. We can test to a wide variety of specifications. Some example specs commonly used in SQF Air Purity are shown below:
BCAS Food and Beverage Grade Compressed Air
|By Particle Size
(maximum number of particles per m3)
|Vapor Pressure Dewpoint||Aerosol & Vapor|
|0.1 µm < d ≤ 0.5 µm||0.5 µm < d ≤ 1.0 µm||1.0 µm < d ≤ 5.0 µm||°C||°F||mg/m3|
|400,000||6,000||100||≤ -40||≤ -40||≤ 0.01|
|400,000||6,000||100||≤ +3||≤ +37||≤ 0.1|
|Microbial Contaminants||Hazard analysis shall establish the risk of contamination by microbiological contaminants from compressed air. The level of control identified as being required over microbiological contaminants in the compressed air shall be detected using the test method specified in ISO 8573-7.|
|Footnotes||(P) Particle classes 1-5 may not be employed if particles >5 micron are present according to ISO 8573-1.|
Direct and Indirect ContactFood Manufacturers should identify compressed air used directly and/or indirectly on or in the product. Some Direct Contact examples include compressed air that is used to mix, cut, move, sort or clean your product. Some Indirect Contact examples include cleaning surfaces the product touches, opening packaging the product goes into, belts that move the product, and pneumatic exhaust that may come into contact with the product.
Contamination SourcesThe last thing any manufacturer wants to do is issue a recall. Compressed air, if properly filtered, maintained, and monitored is a safe utility that is used in numerous manufacturing processes. However, when compressed air purity or compressed air quality is overlooked, it can be a contaminant to your product. Common sources of contamination not only include the compressor, but the intake air, piping, and storage. Ultimately, contamination can come from any number of places.
A Checklist for SQF ComplianceFood manufacturers who have never tested the compressed air purity in their manufacturing facility should:
- Identify all critical control points utilizing compressed air with direct and/or indirect product contact.
- Perform sufficient compressed air purity tests to determine air quality throughout the production facility.
- Evaluate compressed air purity test results.
- Identify the type of filtration installed on the compressed air system and determine if it is sufficient.
- If compressed air does not meet food quality safety standards, consult with your compressor or filtration professionals to determine a plan of action, which may include additional in-line filtration, point-of-use filters, cleaning or replacing of contaminated piping or storage receivers, improved maintenance, personnel training, etc.
- Perform additional air testing to confirm that the problem has been solved.
- Continue to monitor compressed air purity on a quarterly, semi-annual, or annual basis.