Donor milk is processed in a wide variety of ways and handled by many different people ranging from volunteers with no experience in food handling to others with extensive professional experience. Because of this, it should come as no surprise that some terms used in professional processing environments may not have much meaning to those without such experience and they may misuse those terms unintentionally. Here are a few words that are frequently misused in discussions about professional human milk processing along with their actual meanings:
Cleanroom: A cleanroom is not just a “clean” room. It is a specially designed room utilizing air handling systems to maintain positive pressure at all times so that there is an outward flow of air and hepa filters to ensure a low level of particles such as dust, airborne microbes, aerosol particles and chemical vapors. Cleanrooms are very costly to build and must be maintained and monitored on a regular basis. Cleanrooms can be described by Class, such as Class 100, Class 1,000, etc. You can clarify whether a milk bank has an actual cleanroom by asking them about the Class or level or their cleanroom?
What is a Class 10,000 cleanroom or a Class 100,000 cleanroom? A Class 10,000 cleanroom is designed to never allow more than 10,000 particles (0.5 microns or larger) per cubic foot of air and a Class 100,000 cleanroom is designed to never allow more than 100,000 particles per cubic foot of air.
Cleanroom gowning: When entering a cleanroom, workers must first enter a gowning room where they will cover their street clothing with appropriate, lint free, cleanroom garments. Cleanroom garments may include head covering (which should cover 100% of their hair), top and bottoms or a one piece pull-up garment to cover everything from their neck to their wrists and ankles, shoe covers or special cleanroom shoes that never leave the gowning room, gloves, mask to cover nose and mouth, and facial hair covering (to cover beard or sideburns). There are different levels of gowning that correspond to different Classes of cleanrooms. Cafeteria aprons with exposed arms, street shoes without covers and any hair exposed outside of the head covering is insufficient for such a critically sensitive infant food as donor breast milk.
Commercial sterility: This term has a legal meaning and one that has been defined by the Food and Drug Administration. “The FDA Code of Federal Regulations, Title 21-Food and Drugs, Chapter I-Food and Drug Administration Department of Health and Human Services, Subchapter B-Food for Human Consumption, Part 113, Thermally Processed Low-Acid Foods Packaged in Hermetically Sealed Containers, Section e states: “Commercial sterility” of thermally processed food means the condition achieved–(i) By the application of heat which renders the food free of–(a ) Microorganisms capable of reproducing in the food under normal nonrefrigerated conditions of storage and distribution; and (b ) Viable microorganisms (including spores) of public health significance; or (ii) By the control of water activity and the application of heat, which renders the food free of microorganisms capable of reproducing in the food under normal nonrefrigerated conditions of storage and distribution.” Simply culturing pasteurized donor milk after processing to see if any colony forming units remain does not result in a commercially sterile product. Producers of such products must develop the process with an FDA licensed process authority and submit the process and data to the FDA for acceptance.
Homogenization: Some milk banks talk about homogenizing donor milk when they really mean simply mixing and blending the milk so that it becomes more homogeneous. But for professional milk processors, homogenization is a process achieved by either high pressure or ultrasonic treatment to reduce the size of the fat globules in milk or cream in order to distribute them equally throughout the milk. This is important in the NICU because of the problem with feeding tubes becoming clogged by milk that has not been homogenized.
As donor milk use increases, especially in the treatment of fragile preterm infants, it is more important than ever for hospital decision-makers to fully understand the details about how their source of donor milk is processed. If your hospital utilizes donor milk, you deserve to have accurate answers to all of your safety and quality questions. For more information about quality and safety issues that potentially impact the health of preterm infants, click here.