A Guide to Safe Breast Milk Handling: Storage, Preparation, and More

Breast milk provides unparalleled nutrition and immunological support crucial for infant development. Its unique composition delivers essential nutrients and protective factors tailored to a baby's needs. Adhering to safe handling practices is fundamental to preserving these vital qualities and preventing bacterial contamination, ensuring the infant receives the maximum health benefits.

An increasing number of mothers across Canada express and store breast milk for various reasons, including returning to work, managing supply, or allowing partners and caregivers to participate in feeding. Understanding the correct procedures for collection, storage, thawing, and warming is essential. This guide details recommended practices for breast milk storage, preparation techniques, general safety tips, and the role of specialized refrigeration in certain settings.

Breast Milk Composition and Benefits

Human breast milk is a dynamic biological fluid containing a complex array of components essential for infant health and growth. Key constituents include antibodies, primarily Immunoglobulin A (IgA), which coat the infant's intestinal lining, providing passive immunity against pathogens. Enzymes like lipase aid in fat digestion, while lysozyme possesses antibacterial properties. Nutritionally, breast milk offers an optimal balance of proteins (whey and casein), fats (including essential fatty acids like DHA), and carbohydrates (mainly lactose), adapting over time to meet the baby's changing requirements. It also contains live cells, including white blood cells, stem cells, and beneficial bacteria that contribute to gut microbiome development.

Breast milk offers numerous benefits, including immunological protection against infections, reducing the risk of allergies, asthma, obesity, type 1 and 2 diabetes, and certain childhood cancers. It is easily digestible, promoting healthy gut development and brain development. However, proper handling is crucial to maintain its integrity, as temperature fluctuations, improper storage, and incorrect warming methods can degrade nutrients and harmful bacteria. Health Canada supports breastfeeding as the normal and unequal method of infant feeding.

Safe Breast Milk Storage Guidelines

Proper storage, hygiene protocols, temperature-specific time limits, and correct labelling are crucial for preserving the safety and quality of expressed breast milk, preventing accidental use and ensuring traceability.

• Container Selection: Use food-grade glass or BPA-free plastic containers for milk storage, or pre-sterilised bags. Avoid disposable liners or general-purpose plastic bags. Wash containers thoroughly with hot, soapy water, rinse well, or dishwasher, and seal tightly to prevent contamination and nutrient loss.

• Hand Hygiene: Hand washing is crucial before expressing milk or handling equipment. Thoroughly wash hands with soap and warm water for 20 seconds, focusing on fingertips and thumbs. Dry hands with a clean towel. If soap and water are unavailable, use an alcohol-based hand sanitizer.

• Pump Cleaning: To maintain the safety of your breast pump, clean all parts that come into contact with milk after each use, disassemble the kit, rinse thoroughly, wash in hot, soapy water, or a dishwasher, and allow them to air dry completely. Sanitize pump parts daily, especially for infants under three months old or those with weakened immune systems.

• Labelling Containers: Label storage containers with the milk's expression date, baby's name, and waterproof ink or labels. This ensures freshness and minimizes waste, as the oldest milk is used first, maximizing freshness and minimizing waste in childcare settings.

• Room Temperature Storage: Breast milk can be stored at room temperature for up to four hours, with optimal storage at 16°C to 25°C. Warm rooms may require shorter storage. Keep the container covered and away from direct sunlight or heat sources. Use or refrigerate within this timeframe.

• Refrigerator Storage: Store breast milk in the main refrigerator's main body, preferably at or below 4°C, to maintain consistent temperature. Avoid door compartments. Health Canada recommends refrigerated breast milk for up to 4 days for healthy infants, using oldest milk first.

• Freezer Storage: To store breast milk for longer periods, freeze it immediately after expression. In a standard refrigerator freezer compartment, it can last up to 6 months, while in a separate deep freezer or chest freezer maintained at -18°C or lower, it can last up to 12 months. Store at the back of the freezer.

General Breast Milk Handling Tips for Safety

The safety and quality of expressed breast milk are ensured through careful transport, preparedness for power interruptions, illness considerations, awareness of substance transfer, and understanding donated milk protocols, ensuring consistent vigilance.

• Transporting Expressed Milk: To transport expressed breast milk, use an insulated cooler bag with frozen gel or ice packs, seal the containers tightly, and keep the cooler closed. Maintain a consistently cold temperature, similar to refrigeration, throughout transit. Transfer the milk to a refrigerator or freezer as soon as possible upon reaching the destination.

• Power Outages: During a power outage, keep refrigerator and freezer doors closed to maintain cold temperatures. A full freezer can keep food frozen for 48 hours, while refrigerated milk should remain safe for 4 hours. If power is prolonged, transfer milk to a cooler with ice packs. Check frozen milk for ice crystals and refrozen, if necessary, but note slight quality changes. Thawed milk should be used within 24 hours or discarded.

• Illness Considerations: Breastfeeding or expressing milk is recommended for mothers with common illnesses like colds or flus, as the mother's antibodies protect the baby. Maintaining good hygiene, especially hand washing, is crucial for feeding. Breast milk provides essential hydration, nutrition, and immunological support. Consult a healthcare provider for specific concerns or serious illnesses.

• Medication and Substances: Breastfeeding is generally compatible with most medications, but it's crucial to consult a healthcare provider before taking any prescription or herbal supplements. Alcohol consumption should be discussed with a healthcare professional, as substances like nicotine and illicit drugs can be harmful to the infant. Canadian health resources offer guidance on substance use during lactation.

• Donated Milk: Human milk banks offer pasteurized donor human milk to hospitalized, premature, or critically ill infants. Donors undergo rigorous screening, pooled, pasteurized, and tested before distribution. Hospitals follow strict protocols to maintain sterility and safety, and informal milk sharing is discouraged due to potential safety risks.

The Role of Laboratory Refrigerators for Optimal Storage

Standard home refrigerators are adequate for parental breast milk storage, but in clinical settings like NICUs or human milk banks, laboratory or medical-grade refrigerators offer more precise and reliable solutions to maintain the integrity and safety of sensitive biological materials.

• Precise Temperature Control: Laboratory refrigerators are engineered for superior temperature uniformity and stability compared to domestic units. They maintain temperatures within a very narrow range (typically 2°C to 8°C) consistently throughout the storage chamber. This precision is critical for preserving the delicate bioactive components of breast milk, especially when stored for extended periods or for vulnerable infants in NICUs, minimizing degradation caused by temperature fluctuations.

• Advanced Temperature Monitoring and Alarms: These units typically feature digital temperature displays for easy verification and often incorporate sophisticated monitoring systems with data logging capabilities. High and low-temperature alarms (audible and visual) are standard, immediately alerting staff to any deviations from the set safe range, allowing for corrective action before the stored milk's quality or safety is compromised. This is vital in regulated environments like hospitals.

• Forced-Air Circulation Systems: Unlike many domestic refrigerators that rely on cold-wall cooling, laboratory units often utilize forced-air circulation systems. Fans distribute cold air evenly throughout the interior, preventing stratification and eliminating hot or cold spots. This ensures that all stored milk containers experience the same optimal temperature, contributing to consistent quality preservation across all stored samples.

• Enhanced Security Features: In multi-user environments such as hospital wards or milk banks, controlling access to stored breast milk is crucial for safety and preventing errors. Laboratory refrigerators often come equipped with key locks or more advanced access control systems (e.g., keypad or card access). This prevents unauthorized personnel from accessing or tampering with the stored milk, ensuring it reaches the correct infant.

• Design for Hygiene and Ease of Cleaning: Medical and laboratory refrigerators are constructed with materials like stainless steel interiors and exteriors, and often feature smooth, easily accessible surfaces and adjustable shelving. This design facilitates thorough cleaning and disinfection, essential practices in healthcare settings to minimize the risk of cross-contamination between samples or the introduction of nosocomial pathogens.

• Meeting Regulatory and Clinical Standards: Refrigerators designed for medical or laboratory use are built to meet specific performance and safety standards relevant to healthcare and research (e.g., certain CSA or NSF standards). Their construction, temperature performance, and monitoring capabilities align with the rigorous requirements for storing biological products, including human milk intended for therapeutic use in vulnerable populations.

• Backup Power Compatibility: Many laboratory-grade refrigerators feature systems compatible with hospital backup power generators. Some may also include battery backup systems specifically for the temperature monitoring and alarm functions, ensuring continuous oversight and alerts even during short power interruptions before backup generators engage, safeguarding valuable stored milk supplies.

Adhering to evidence-based guidelines for handling expressed breast milk is crucial for infants' nutritional and immunological benefits. Proper techniques like expression hygiene, container selection, storage duration, temperature, thawing, and warming minimize contamination and preserve milk quality. Following protocols like Health Canada and the Canadian Pediatric Society supports infant health and development.

Understanding milk storage practices helps parents and caregivers provide optimal nourishment. For hospitals or milk banks, specialized equipment like laboratory-grade refrigerators offer safety and quality assurance. For medical-grade refrigeration solutions for sensitive biologicals like breast milk, contact 360 Degree Medical at 1-800-209-2082.