How does a 72 hour dry ice pack sheet keep goods frozen?
When shipping frozen goods, a 72 hour dry ice pack sheet uses solid carbon dioxide (dry ice) to maintain temperatures around –78.5 °C and keep parcels frozen for 24–72 hours. Dry ice sublimates directly from solid to gas, releasing no liquid and absorbing heat from the surroundings. By matching the mass of dry ice to your product weight and using high quality insulation, you can achieve up to three days of sub zero storage. This guide demystifies the science of sublimation, explains how to select and pack 72 hour sheets, outlines safety and regulatory requirements, and explores the latest 2025 innovations to help you protect perishables and biologics.
What is a 72 hour dry ice pack sheet and how does it work? — understand sublimation, insulation and moisture free cooling.
How much dry ice do you need for 72 hour shipments? — learn the 1:1 and 1.5× weight rules and how to adjust for season, route and insulation quality.
How should you package and handle dry ice sheets? — follow step by step instructions for layering, venting and labeling.
Dry ice sheets vs. gel packs: which is better? — compare temperature ranges, durations and use cases.
What innovations and trends are emerging in 2025? — explore hybrid packs, reusable sheets, smart sensors and eco friendly materials.
What is a 72 hour dry ice pack sheet and how does it work?
Direct answer and key points
A 72 hour dry ice pack sheet is a flexible, sealed pouch filled with solid carbon dioxide (dry ice) designed to keep products frozen for up to three days. Unlike traditional ice, dry ice sublimates directly from solid to gas at –78.5 °C. This sublimation absorbs heat and prevents any water residue, keeping your packaging and products dry. By combining dry ice with thick insulation—such as expanded polystyrene (EPS), polyurethane (PUR) or vacuum insulated panels (VIPs)—a properly sized sheet can maintain frozen temperatures for 48–72 hours. The key to achieving a three day hold is matching the dry ice mass to your shipment weight and ensuring that CO₂ gas can vent safely.
How dry ice sheets differ from gel packs and water ice
Dry ice sheets and packs are flexible pouches filled with dry ice pellets or blocks. They differ from gel packs, which freeze around 0 °C and thaw slowly, and from water ice, which melts into liquid. Dry ice sublimates directly to gas, leaving no moisture. Gel packs maintain refrigerated temperatures (2–8 °C) and are reusable but may leak, while water ice melts at 0 °C and lasts only 12–24 hours. Disposable dry ice packs, when properly insulated, can last up to 72 hours.
Sublimation science: how dry ice keeps goods frozen
Dry ice is the solid form of carbon dioxide. At atmospheric pressure it does not melt into liquid; instead, it sublimates directly into gas, absorbing heat from its surroundings and maintaining sub zero temperatures. Because it turns into gas, there is no watery residue, which avoids soggy packaging and water damage. However, CO₂ gas can accumulate and displace oxygen in confined spaces, so proper ventilation is essential.
Types of dry ice cooling solutions
| Cooling solution | Temperature range | Typical duration | Meaning for you |
| Mini dry ice sheet | –78.5 °C to –18 °C | 24–48 h | Ideal for pharmaceuticals or biologics requiring ultra low temperatures; no moisture risk. |
| Disposable dry ice pack | –78.5 °C | Up to 72 h | Perfect for long distance shipping of frozen meat, seafood or vaccines; single use convenience. |
| Gel pack | 2 °C–8 °C | Up to 48 h | Keeps produce, dairy or medicines cool without freezing; reusable but may leak. |
| Traditional water pack | ≈ 0 °C | 24–36 h | Inexpensive solution for short journeys; limited thermal mass and moisture leakage risk. |
Practical tips and user advice
Choose the right form: Blocks have less surface area than pellets and sublimate more slowly; hybrid packs encase pellets in gel or phase change materials (PCM) to extend cooling to 48–72 hours.
Pre freeze your product and container: Freeze goods to at least –18 °C and pre chill the container to slow down sublimation.
Select appropriate insulation: Vacuum insulated panels (VIPs) are up to five times more efficient than standard foam; upgrade to VIPs to reduce dry ice mass by 20–40 % for long transit.
Vent properly: Never seal dry ice in an airtight container; provide channels for CO₂ to escape.
Label and comply: Mark packages with “Dry Ice” or “Carbon dioxide, solid,” include the UN 1845 number and net weight.
Real world case: A specialty dessert company switched from loose pellets to a combination of one top block, a thin pellet blanket and a reflective liner. The change extended frozen hold time by 10–14 hours and reduced carrier rejections. This illustrates how layering and insulation upgrades can improve performance.
How much dry ice do you need to keep shipments frozen for 72 hours?
Direct answer and guidelines
The amount of dry ice required depends on the weight of your shipment, duration and ambient conditions. A simple rule of thumb is to match the weight of dry ice to the weight of your product for 48 hour shipments. To achieve 72 hours, you need roughly 1.5 times the product weight in dry ice. For example, shipping a 10 lb box of frozen seafood would require about 15 lb of dry ice. Another rule is 5–10 lb of dry ice per 24 hours for every 10–15 lb of product. Always add a 15–25 % buffer for high ambient temperatures or weekend delays.
Calculating dry ice quantity and adjusting for variables
Several factors influence how much dry ice you need:
Seasonal temperatures: Summer shipments need 25–35 % more dry ice than winter shipments because higher ambient temperatures accelerate sublimation.
Route complexity: Multi handoff routes require an additional 10–15 % dry ice to buffer delays and handling.
Insulation quality: Upgrading from standard foam to VIP panels can reduce dry ice requirements by 10–25 %, saving weight and cost.
Product state: Pre frozen goods require less dry ice than those packed at room temperature.
Hybrid packouts: Combining dry ice with gel or PCM can reduce CO₂ usage while maintaining multiple temperature zones.
Adjusting dry ice quantity for season and route
| Product weight | Starting dry ice (1:1) | When to add more | Practical benefit |
| 4 lb | 4–5 lb | Hot climates or peak summer | Ensures 48 h freeze protection. |
| 8 lb | 8–10 lb | Complex routes with multiple handoffs | Consider VIP insulation if weight is restricted. |
| 12 lb | 12–15 lb | Very hot lanes or expected delays | Combine hybrid packouts with monitoring. |
| 20 lb | 20–30 lb | Long distance or weekend shipments | Spread dry ice around the payload to eliminate warm pockets. |
| 50 lb | 50 lb top + 25 lb bottom | Large loads require bottom placement | Ensures even cooling and prevents hot spots. |
Practical tips and user advice
Calculate conservatively: Use the higher end of recommended ranges and add a 24 hour buffer to account for delays.
Match insulation to duration: Use 1–1.5 inch EPS/PUR for short trips, 1.5–2 inch foam for moderate duration and VIP panels for shipments over 72 hours.
Pre cool containers: Chill the empty cooler for at least one hour before packing.
Separate dry ice from food: Use cardboard or trays to prevent freezer burn.
Weigh and label accurately: Record the net mass of dry ice on the package to meet carrier limits and avoid delays.
Real world example: In ambient temperatures of 70 °F (21 °C), a Styrofoam cooler with 15 lb of dry ice kept meat frozen for roughly 72 hours. Doubling the dry ice extended the hold time to several days. This demonstrates the importance of adjusting dry ice mass based on desired duration.
Packaging and safety practices for 72 hour dry ice pack sheet shipments
Direct answer and key principles
Correct packaging maximizes hold time, protects your product and ensures safety. Start by pre freezing your goods to at least –18 °C and choose a rigid, insulated container—often a corrugated box with EPS, PUR or VIP liner. Plan the dry ice quantity using the guidelines above and layer it around the product: place blocks or pellets at the base, add the frozen product in a sealed bag, then surround the sides and top with additional dry ice. Always vent the container, leaving small gaps for CO₂ to escape, and avoid sealed plastic bags. Finally, label the package with the proper name, UN number and net weight, and train handlers to wear gloves and goggles.
Layering and venting: step by step packing process
Follow these steps to assemble a durable package:
Pre freeze and prepare: Freeze the product to –18 °C and confirm it can tolerate ultra cold temperatures.
Select container and liner: Choose a sturdy corrugated box; insert an EPS or PUR liner or upgrade to VIP for long transit.
Calculate dry ice quantity: Use 5–10 lb per 24 hours per 10–15 lb of product, adjusting for weight and insulation; add a 24 hour buffer.
Layer the dry ice: Place blocks or pellets at the bottom, add the product in a sealed bag, then surround the sides and top with additional dry ice.
Vent and close: Seal the liner but leave vent holes; lightly tape the outer box, leaving small gaps for CO₂ to escape.
Label and document: Affix hazard labels, write “Dry Ice/Carbon dioxide, solid” and UN 1845, and state the net weight in kilograms.
Train and monitor: Educate handlers to wear gloves and goggles; include a temperature logger to monitor conditions.
Longevity factors and practical meaning
| Longevity factor | Impact on sublimation | Practical meaning |
| Ice form (blocks vs. pellets) | Blocks have less surface area and last longer; pellets sublimate faster | Choose blocks or a combination of blocks and pellets for shipments longer than 48 h. |
| Insulation quality | VIPs are up to five times more efficient than polystyrene foam | Upgrade to VIP or thick PUR for 72 h lanes to reduce required dry ice. |
| Payload pre freezing | Starting with a cold product reduces the cooling load | Freeze goods to at least –18 °C before packing to extend hold time. |
| Void fill and reflective liners | Tight voids and reflective barriers reduce heat transfer | Fill empty spaces with paper or bubble wrap and use reflective liners to add 10–14 h of protection. |
| Venting | Allows CO₂ gas to escape and prevents pressure build up | Use vented lids or punch holes in the outer box to ensure safety and maintain cold airflow. |
Practical tips and user advice
Match insulation to duration: Use VIP panels for shipments longer than 72 hours; they can reduce dry ice mass by 20–40 %.
Use layered “sandwich” packing: Placing dry ice at the base, sides and top eliminates warm pockets and cut delivery failures by 38 % in a pastry company case study.
Train customers: Include instructions on safe handling and disposal to prevent frostbite and CO₂ exposure.
Avoid overpacking: Extra dry ice increases cost and may trigger hazmat limits; aim for the right balance of mass and insulation.
Explore reusable systems: Programs like InfiniDI combine advanced insulation and return logistics to cut dry ice usage by 50 % and reduce waste up to 90 %.
Real world case: Foam containers with VIP inserts can retain temperatures for 96–240 hours while reducing dry ice mass by 20–40 %. Layering dry ice as base blocks, side slabs and top pellets decreased delivery failures by 38 %.
Dry ice sheets vs. gel packs: which is better for your shipment?
Direct comparison and key insights
Dry ice sheets reach temperatures as low as –78.5 °C, making them ideal for products that must remain frozen, such as frozen meat, seafood, vaccines and biologics. They sublimate without leaving moisture, so packaging stays dry and there is no risk of water damage. Gel packs, by contrast, maintain temperatures between 2 °C and 8 °C and are suitable for products that should not freeze, such as fresh produce, dairy, chocolates or pharmaceuticals that require refrigeration. Gel packs are non hazardous, safe to handle and reusable, but they may leak and provide a shorter cooling duration (up to 48 hours).
Temperature ranges and use cases
| Cooling method | Temperature range | Typical duration | Best for |
| Dry ice sheet (72 h) | –78.5 °C to –18 °C | 36–72 h with proper insulation | Frozen meat, seafood, vaccines, biologics, ice cream and meal kits requiring sub zero temperatures. |
| Gel pack | 2 °C–8 °C | Up to 48 h | Fresh produce, dairy products, chocolates, chilled pharmaceuticals; items that must not freeze. |
| Water ice | ≈ 0 °C | 12–24 h | Short journeys and low value perishables; risk of leakage and soggy packaging. |
Advantages and limitations
Advantages of dry ice sheets:
Ultra low temperature: Maintains –78.5 °C, preserving frozen goods for days.
Moisture free cooling: Sublimates to gas, leaving no residue.
Longer duration: With proper insulation, disposable dry ice sheets can last up to 72 hours.
Compact and flexible: Pack sheets can be cut to size and positioned around the product.
Limitations of dry ice sheets:
Hazard classification: Dry ice is a Class 9 hazardous material; shipments over 2.5 kg require hazmat labels and compliance with IATA Packing Instruction 954.
Handling risks: Contact can cause severe frostbite; handlers must wear insulated gloves and goggles.
Cost and availability: Demand for dry ice is growing about 5 % per year, while supply grows only 0.5 %, leading to price surges.
Advantages of gel packs:
Non hazardous: No special labels or hazmat handling required.
Reusable: Many gel packs can be refrozen and reused multiple times.
Suitable for non frozen products: Keeps goods between 2 °C and 8 °C without freezing.
Limitations of gel packs:
Shorter duration: Up to 48 hours in typical conditions.
Moisture risk: Gel packs may leak or sweat, potentially damaging packaging.
Less cold: Cannot achieve ultra low temperatures; unsuitable for frozen items.
Practical tips and user advice
Match refrigerant to your product: Use dry ice for frozen goods and gel packs for refrigerated items.
Combine dry ice and gel: For shipments exceeding two days, carriers like UPS recommend pairing dry ice with gel packs to slow sublimation and maintain temperature.
Provide handling instructions: When shipping with dry ice, include clear instructions to prevent recipient injury.
Consider costs and regulations: Dry ice shipments may incur hazmat fees; gel packs are simpler but may require more volume.
Real world case: A Los Angeles dessert company replaced loose pellets with slow thaw packs and PCM gels. Transit time increased from 36 hours to 60 hours, CO₂ consumption dropped 20 %, and customer complaints about freezer burn nearly disappeared. This demonstrates how hybrid approaches can extend duration and improve product quality.
2025 innovations and market trends for 72 hour dry ice pack sheets
Trend overview
The cold chain landscape is evolving rapidly. In 2025, several innovations are reshaping durable dry ice pack sheets:
Hybrid and multi zone packaging: Combining dry ice and phase change materials creates multiple temperature zones in one container. This allows simultaneous shipment of frozen and refrigerated products and reduces dry ice consumption.
Advanced gel sheets: New gel sheets hold temperatures of –12 °C to –18 °C for up to 48 hours and can be reused over 30 cycles, offering a cost effective alternative to pure dry ice.
Smart sensors: NFC and Bluetooth temperature loggers provide real time monitoring and alerts, helping shippers detect temperature excursions and respond proactively.
Eco friendly materials: Manufacturers are developing biodegradable insulation and capturing CO₂ from renewable sources, reducing environmental impact.
Regulatory updates: FSMA deadlines and stricter IATA rules push shippers to adopt vented packaging and improved traceability.
Latest developments at a glance
CO₂ supply challenges: Dry ice demand is growing about 5 % per year, while supply increases only 0.5 %, leading to price surges. Hybrid packs help mitigate shortages by reducing CO₂ consumption.
Non hazard classification: Some hybrid packs encase CO₂ in sealed cells and combine PCM gels, making them non hazardous and exempt from Class 9 labels.
Reusable pack sheets: Flexible dry ice pack sheets deliver –40 °C to –60 °C for 36–72 hours and are reusable.
Market growth: The global cold chain logistics market is projected to grow from $242.39 billion in 2021 to $647.47 billion by 2028, a compound rate of 15.1 %.
Smart sensors and sustainability
Smart temperature monitoring: Modern dry ice pack sheets often include pockets for NFC or Bluetooth sensors. These sensors record real time temperature data and transmit alerts if the temperature moves outside the target range. Monitoring allows you to validate performance, identify weak points and adjust packaging for future shipments.
Sustainable practices: Capturing CO₂ from renewable sources reduces the carbon footprint of dry ice production. Reusable pack sheets and hybrid systems cut CO₂ usage by 20–40 % and reduce waste by up to 90 %.
Regulatory compliance: Stricter FSMA and IATA regulations require better traceability and vented packaging. Shippers must label packages with the proper name, UN 1845 and net weight. Some hybrid packs are exempt from hazardous classification when CO₂ is sealed in cells.
Market insights
Consumers expect fresh groceries, ready to cook meal kits and sensitive medicines delivered safely to their doorstep. Businesses must reduce spoilage, comply with food safety regulations and minimise carbon emissions. Durable dry ice packs address these pressures by offering extended cooling, reduced CO₂ usage and improved sustainability. They support e commerce growth by enabling reliable two to three day deliveries and help companies avoid the high cost and complexity of refrigerated trucks. Adoption of VIP insulation and smart monitoring further enhances performance and traceability. As 2025 unfolds, shippers who invest in these innovations will gain a competitive edge.
Frequently asked questions
Q1: How long will a 72 hour dry ice pack sheet last?
A properly packed dry ice parcel can maintain frozen temperatures for 24–72 hours. Using 5–10 lb of dry ice per 10–15 lb of product and high quality insulation extends hold time. Hybrid slow thaw packs can stretch cooling to 36–72 hours with less CO₂.
Q2: Is dry ice safe to handle?
Dry ice is extremely cold (–78.5 °C) and can cause severe frostbite on contact. Always wear insulated gloves and goggles and use tongs when handling dry ice. Never store dry ice in an airtight container; always provide ventilation.
Q3: Do I need a shipper’s declaration for dry ice?
Typically not if dry ice is the only hazardous item. You must label the package with “Dry Ice,” UN 1845 and net weight, and attach a Class 9 hazard label for air shipments. Declarations may be required when shipping additional dangerous goods or when exceeding carrier limits (2.5 kg on passenger aircraft). Check specific carrier rules.
Q4: Can I reuse dry ice pack sheets?
The CO₂ itself cannot be re frozen, but many hybrid dry ice pack structures and gel sheets can be reused over 30 cycles, reducing cost and waste. Refillable systems cut dry ice usage by 50 % and reduce waste by up to 90 %.
Q5: How do I dispose of leftover dry ice?
Let dry ice sublimate outdoors or in a well ventilated area. Do not put it in sinks or drains. Gel packs can often be reused or emptied into general waste if non toxic.
Summary and recommendations
Key takeaways: A 72 hour dry ice pack sheet combines solid CO₂, high quality insulation and proper venting to keep products frozen for three days. Match the dry ice weight to your product weight (1:1) for 48 hour shipments and use 1.5× weight for 72 hours. Upgrade insulation to VIP panels to reduce dry ice mass by 20–40 %, and layer dry ice at the base, sides and top to eliminate warm pockets. Always pre freeze products, vent containers and label packages with UN 1845 and net weight. Consider hybrid packs, reusable sheets and smart sensors to reduce CO₂ usage and monitor temperatures.
Actionable guidance:
Assess your needs: Determine the required temperature range and transit duration. Decide whether you need pure dry ice, a hybrid pack or PCM.
Calculate and prepare: Estimate dry ice mass using the guidelines above, pre freeze your product and choose the right insulation (EPS, PUR or VIP).
Pack and vent: Layer dry ice correctly, fill voids and ensure vents for CO₂ escape. Avoid overpacking and always separate dry ice from the product.
Label and comply: Mark packages with “Dry Ice,” UN 1845 and net weight; attach hazard labels as required and follow IATA PI 954 for air shipments.
Monitor and innovate: Use temperature loggers to track conditions. Explore reusable dry ice programs, smart sensors and eco friendly insulation to reduce costs and improve sustainability.
About Tempk
Company background: Tempk is a pioneering provider of cold chain packaging solutions. Our portfolio includes gel packs, vacuum insulated panels, slow thaw dry ice packs and reusable phase change systems. We combine decades of industry experience with cutting edge research to deliver reliable, eco friendly solutions. VIP liners and hybrid dry ice packs engineered by our team help customers achieve 96–240 hours of cold retention with reduced CO₂ usage. We adhere to international regulations and support clients with compliance training and smart sensor integration.
Call to action: Ready to upgrade your cold chain? Contact Tempk for a personalised consultation. Our experts will help you select the best 72 hour dry ice pack sheet or hybrid solution for your application. Together we can protect your products, reduce waste and stay ahead of 2025 innovations.
