Shipping seafood safely requires precision. Your fish must arrive frozen or perfectly chilled, so using the right cooling agent is critical. Dry ice packs remain the gold standard for keeping seafood below freezing because they sublimate directly into carbon dioxide gas at –78.5 °C (–109,3 °F), meaning there’s no messy meltwater. This article explains why dry ice packs are ideal for frozen seafood, how to calculate the correct quantity, and how to pack shipments for maximum freshness and safety. You’ll also discover emerging trends like reusable and smart dry ice packs and learn when gel packs or hybrid cooling may be better.
Why choose dry ice packs for shipping seafood? — examines temperature control, longevity and dryness
How do dry ice packs compare with gel packs or water ice? — contrasts temperature ranges, duration and moisture
How much dry ice do you need and how do you pack it? — uses formulas and step by step instructions
What regulations and safety precautions apply? — covers hazard classifications, handling and labeling
¿Cuáles son los 2025 trends in dry ice packs for seafood? — explores reusable packs, smart sensors and sustainability
Why are dry ice packs ideal for seafood shipping?
Extreme cold without water residue. Dry ice packs consist of solid carbon dioxide that sublimates directly into gas; this property allows them to maintain extremely low temperatures (down to –78.5 °C) without creating liquid, preventing soggy packaging and bacterial growth. Gel packs freeze at around 0 °C–8 °C (32 °F–46 °F) and eventually produce meltwater, while water ice melts into liquid. Because dry ice produces no liquid residue, it keeps seafood packaging dry and avoids cross contamination.
Duración de enfriamiento más larga. Dry ice lasts longer than water ice or gel packs because sublimation absorbs heat during the phase change. A typical dry ice pack can provide continuous cooling for 24–48 hours, and with the right pack size or by combining it with gel packs this can extend up to 72 hours. Gel packs generally provide 6–12 hours of cooling before they begin to warm. For cross country or international shipments, the extended duration of dry ice makes it indispensable.
No contamination and lighter weight. Dado que el hielo seco se sublima en gas, packages remain dry and free of bacterial growth. Dry ice packs are also compact and lightweight compared with bulky gel packs, which can reduce shipping costs and maximize usable space.
Reusability and sustainability. Many dry ice packs today use reusable outer sleeves or vented materials that can be recharged with new CO₂ pellets after each trip. This reduces waste and lowers costs over time. Manufacturers are now producing eco friendly dry ice using recycled CO₂ captured from industrial emissions and renewable energy. Some packs also feature biodegradable materials or plant based gels, making them more sustainable.
Comparing dry ice packs with gel packs and water ice
Below is a comparison of common refrigerants for seafood shipping. The table summarises their typical temperature range, duración, moisture behavior and best use cases:
| Método de enfriamiento | Rango de temperatura | Duración | Comportamiento de la humedad | Mejor para |
| Paquete de hielo seco | –78,5°C (–109°F) | 24–48 hours, up to 72 hours with optimal insulation | Ninguno (Susilimaciones) | Frozen seafood or long distance shipments; compact and residue free |
| Paquete de gel | 0 °C–8 °C (32 °F–46 °F) | 6–12 hours | Produces meltwater | Chilled seafood or short trips; reusable and flexible |
| Water ice | ~ 0 ° C (32 ° F) | 6–8 hours | Melts to liquid | Low cost option for local deliveries or non perishable items |
Para la punta: For live fish or shellfish, avoid dry ice because the extreme cold and CO₂ gas can harm living specimens. Use gel packs or crushed ice to maintain a chilled environment without freezing.
Calculating how much dry ice to use and packing steps
Dry ice quantity formulas
To keep seafood frozen during transit, you need enough dry ice to compensate for sublimation and heat infiltration. A common rule of thumb is 5–10 pounds of dry ice per 15 quarts of cooler space per 24 hour transit period. UPS notes that five to ten pounds of dry ice will sublimate every 24 hours and recommends adding enough for an additional 24 hours as a safety buffer.
For more precise planning, Tempk provides a formula:
hielo seco (libras) = Payload weight (libras) × 0.25 × (Transit hours ÷ 24) × insulation factor.
This equation accounts for the weight of the fish, transit duration and container efficiency. Por ejemplo, shipping 20 lbs of frozen fish for 48 hours using an efficient foam cooler (insulation factor = 1) requires 20 × 0.25 × (48 ÷ 24) = 10 lbs of dry ice; adding a 25 % buffer brings the total to 12.5 lbs.
Step by step packing instructions
Choose high quality insulation. Use containers made from expanded polystyrene (EPS) or polyurethane foam for thermal resistance. Avoid airtight boxes; there must be room for gas to escape. Pre freeze and pre chill both the fish and the cooler before packing to reduce the initial temperature load.
Layer your shipment. Create a bottom layer of foam or corrugated cardboard to buffer the dry ice. Arrange the fish pieces individually in the middle layer, leaving space for air circulation. Place dry ice packs on top to create a “cold dome” over the fish. This arrangement allows the cold CO₂ gas to sink around the product, maintaining consistent sub zero temperatures.
Fill voids and provide ventilation. Use crumpled paper or additional insulation to eliminate air gaps and reduce heat exchange. Leave vents or small cracks in the container lid so CO₂ gas can escape, preventing pressure build up. Never seal a dry ice box airtight.
Separate dry ice from fish. Insert a spacer or layer of cardboard between the dry ice and the fish to avoid direct contact and freezer burn. If shipping live seafood or delicate fillets, add gel packs to maintain a slightly higher temperature and prevent freezing.
Utilice registradores de datos. Attach a temperature logger inside the package to monitor conditions during transit and provide proof of compliance with regulations. For shipments lasting more than two days, combining dry ice with gel packs or phase change materials (PCM) can extend cooling while reducing the total amount of dry ice needed.
Seal and label properly. Close the outer cardboard box securely but do not make it airtight. Label the shipment clearly with “Dry Ice” and the peso neto de hielo seco en kilogramos as required by U.S. and international regulations. Include any necessary handling instructions and safety documentation, such as a Material Safety Data Sheet (MSDS).
Example packing scenario
Imagine shipping 10 lbs of frozen salmon for a 24 hour overnight delivery. According to the rule of thumb, you would use roughly 5 lbs of dry ice (half the weight of the fish) and pack the salmon in a styrofoam cooler. Pre freeze the fish, add a layer of foam, place the fish and insulate with crumpled paper, then lay the dry ice packs on top. Seal the cooler inside a corrugated box with ventilation holes and label it accordingly. This setup will keep the fish frozen with no meltwater and arrive ready to cook or sell.
Regulatory requirements and safety
El hielo seco se clasifica como un Material Peligroso (Y 1845). Los EE. UU.. Code of Federal Regulations and IATA rules limit air shipments to about 2.5 kg (5.5 lb) de hielo seco por paquete. Carriers like UPS require training and appropriate labeling, including the UN number and net weight. International shipments must follow IATA Packing Instructions 954 and may require a signed International Special Commodities (ISC) contract.
Handling precautions
Wear protective equipment. Always wear thermally insulated gloves, goggles and long sleeves to prevent frostbite. Use tongs to handle dry ice when possible, and never let it come into contact with bare skin.
Ventilate and store properly. Store dry ice in a well ventilated area and avoid airtight containers; sublimation can cause pressure build up and explosion. Never store dry ice in glass containers or the trunk of a car without ventilation.
Desechar de forma segura. Allow leftover dry ice to sublimate outdoors or in a ventilated space. Do not pour dry ice into sinks or trash bins.
Follow quantity limits. For overnight or short trips under 24 hours, use dry ice equal to half the weight of your fish; for medium trips (24–48 hours), usar equal weight; and for extended trips (48–72 horas), usar one and a half times the weight of the fish and consider adding gel packs.
Real world lessons
An illustrative case from Tempk describes a small fishery that sealed a dry ice package too tightly. CO₂ gas built up and burst the box during transit, damaging the shipment and creating a safety hazard. By leaving ventilation holes and following proper labeling guidelines, you can avoid such accidents and keep carriers and customers safe.
Choosing the right dry ice pack for different seafood shipments
Selecting the optimal dry ice pack depends on shipment duration, fish type and sustainability goals. Here’s how to tailor your choice:
Assess duration and required cooling
| Duración del viaje | Recommended dry ice amount | Razón |
| Viajes cortos (under 24 hours) | Half the weight of the fish | Keeps product frozen while limiting CO₂ release |
| Medium trips (24–48 hours) | Equal weight of dry ice and fish | Maintains freezing temperatures through a two day journey |
| Extended trips (48–72 horas) | 1.5 × fish weight plus gel packs | Provides extra buffer and slows sublimation for long distances |
Match pack size to shipment volume
Larger shipments may require multiple reusable dry ice packs to distribute cooling evenly. For small or moderate shipments, one pack might suffice; always ensure each pack is fully charged with dry ice pellets before use. When shipping premium fillets or delicate fish, use extra insulation and more dry ice to prevent any temperature rise because customers expect pristine quality. Bulk frozen fish shipments may benefit from larger packs or several smaller packs to maximize container space and reduce cost per pound.
Consider customer values and sustainability
Sustainably minded clients appreciate dry ice packs made from recyclable materials or eco friendly dry ice produced via carbon capture technologies. Reusable packs reduce environmental impact by allowing repeated use. Some manufacturers now offer smart dry ice packs with built in IoT sensors that monitor temperature and alert you if conditions deviate. Others use biodegradable CO₂ sources to minimize emissions. When choosing a pack, evaluate durability, ease of recharging and end of life recyclability.
Fresh vs frozen: packaging considerations
Chilled or live seafood
Pescado fresco, pre chilled fillets and live shellfish require temperatures just above freezing (0 °C–4 °C). For these products, gel packs or crushed ice are safer because they maintain a cool environment without freezing the fish. BlueCart’s shipping guide recommends wax boxes when shipping fresh or wet seafood with ice because they resist humidity, mientras styrofoam boxes are preferable for frozen seafood and dry icebluecart.com. Always wrap fish in plastic or foil and cover with ice to keep it moist; for shellfish, place them in shallow pans without standing water and cover with moist paper towelsbluecart.com.
Mariscos congelados
Frozen fish must remain below –18 °C (0 ° F). Dry ice packs excel here because they maintain consistent sub zero temperatures and prevent thawing. Pack frozen fish in sturdy styrofoam containers or high density EPS coolers and avoid direct contact between the dry ice and the fish. Fill voids with insulation and seal the outer box securely but with ventilation holes. Por regla general, ship frozen seafood early in the week to avoid weekend delays.
2025 trends in dry ice packs and cold chain logistics for seafood
Descripción general de la tendencia
The cold chain industry is innovating rapidly to meet growing demand for fresh, sustainably sourced seafood. Sustainability initiatives are driving manufacturers to produce dry ice using renewable energy and carbon capture technologies, reducing the carbon footprint of shipping. Reusable packs and smarter logistics not only reduce waste but also lower shipping costs by reducing spoilage and returns.
Últimos avances de un vistazo
Smart dry ice packs: Equipped with IoT sensors, these packs provide real time temperature data and send alerts if the shipment leaves the safe range. This helps shippers comply with safety regulations and adjust cooling during unexpected delays.
Eco friendly CO₂ production: Innovations such as carbon capture and renewable energy sources create dry ice with a lower carbon footprint. Biodegradable dry ice wraps and reusable containers further reduce environmental impact.
Enfriamiento híbrido: Combining dry ice with phase change materials (PCM) or gel packs extends cooling duration while reducing the total amount of dry ice required. Hybrid systems help prevent freezer burn and can keep seafood within a narrow temperature band.
AI driven cold chain optimisation: Artificial intelligence optimizes routing, predicts delays and adjusts cooling needs in real time, ensuring fish arrives fresh while minimizing energy consumption.
Ideas del mercado
Consumers expect fresher seafood and greater transparency. Growing demand for sustainably sourced fish is pushing the cold chain market to adopt reusable packaging, advanced monitoring and greener CO₂ production. As regulations emphasise carbon reduction, expect the market for reusable cold chain packaging to expand significantly in the coming decade.
Preguntas frecuentes
Q1: How long do dry ice packs keep seafood frozen?
Dry ice packs can keep fish frozen for 24–48 hours and up to 72 hours when using larger quantities or combining them with gel packs. Proper insulation and venting are essential to achieve maximum duration.
Q2: Are dry ice packs safe to handle?
Yes—if handled correctly. Always wear protective gloves and goggles and avoid direct contact with dry ice to prevent frostbite. Use proper ventilation to release CO₂ gas and never seal the box airtight.
Q3: ¿Puedo reutilizar paquetes de hielo seco??
Sí. After the dry ice sublimates, allow the pack to dry completely, then recharge it with new CO₂ pellets. Ensure there is no moisture or damage before re use.
Q4: Is dry ice suitable for live fish or shellfish?
No. The extreme cold and CO₂ gas can harm live seafood. Use gel packs or water ice instead.
Q5: What regulations apply to dry ice shipments?
El hielo seco se clasifica como un material peligroso. The FAA and IATA limit packages to 2.5 kg (5.5 lb) de hielo seco, and shipments require specific labeling and documentation.
Resumen y recomendaciones
Shipping seafood successfully hinges on maintaining the correct temperature throughout transit. Dry ice packs provide ultra low temperatures, long lasting cooling and zero meltwater, making them the best option for frozen seafood shipments. To use dry ice safely, calculate the required amount based on weight and travel time, layer your package properly and leave ventilation holes to release CO₂ gas. Always wear protective gear and comply with labeling and quantity regulations. For fresh or live seafood, choose gel packs or ice instead. Looking forward, innovations like reusable and smart dry ice packs, carbon neutral CO₂ production and AI optimised logistics will make seafood shipping safer, greener and more efficient.
Next steps for your seafood business
Evalúe sus necesidades de envío: Determine whether you are shipping fresh, live or frozen seafood and choose the appropriate cooling method (gel packs for chilled shipments and dry ice packs for frozen shipments).
Invierte en envases de calidad: Purchase insulated containers made from EPS or polyurethane and reusable dry ice packs that can be recharged for future shipments. Include temperature loggers to monitor transit conditions.
Implement sustainable practices: Explore eco friendly dry ice sources and reusable packs, and communicate these efforts to your customers.
Stay informed on regulations: Keep up with FAA and IATA requirements and train staff on safe handling and labeling procedures.
Plan shipments strategically: Enviar a principios de la semana, choose reliable carriers experienced with perishable goods, and consider hybrid cooling or smart packs for long transits and high value seafood.
Acerca de Tempk
Tempk is a leading provider of cold chain solutions for food, pharmaceutical and biotech industries. Our research driven approach has led to innovations such as reusable dry ice sheets and smart temperature monitoring systems. We are committed to sustainability, using recycled CO₂ in our dry ice products and offering biodegradable insulation materials. With decades of experience and rigorous quality control, we help businesses maintain product integrity and comply with global regulations. For personalized guidance on your seafood shipping challenges, reach out to our team.
Llamado a la acción
Ready to optimise your seafood shipments? Contact our cold chain experts for a personalised consultation and discover how our reusable dry ice packs and smart monitoring solutions can keep your seafood fresh while reducing costs and environmental impact.
