Small Pack of Dry Ice: Pack, Ship, and Fly Safely in 2025

Updated: September 2, 2025. If you use a small pack of dry ice to keep products frozen, this guide shows you exactly how to size it, pack it, and meet 2025 airline and carrier rules. You’ll get a rule‑of‑thumb calculator, safety steps that prevent damage, and simple compliance checklists tailored to real lanes. (Consolidated from Tempk internal drafts and 2025 regulatory notes.)

What counts as a small pack of dry ice? Practical ranges and hold‑time basics.
How to pack a small pack of dry ice? A safe, step‑by‑step method with venting.
Can you fly with a small pack of dry ice? The 2.5 kg passenger limit made simple.
How much should you buy? A quick estimator for 24–72 h lanes.
When not to use dry ice? When −20 °C/−25 °C PCM beats dry ice for compliance.

What is a small pack of dry ice and when should you use it?

Direct answer: A small pack of dry ice is typically 1–5 lb (0.45–2.27 kg) of solid CO₂ used to keep items frozen for short trips or 1–2‑day shipments. Plan on 5–10 lb per 24 h in a standard hard cooler; warmer ambient, frequent openings, and poor insulation raise the need. Use a vented container and gloves. For chilled (2–8 °C) goods, choose +5 °C PCMs instead to avoid freezing.

Why it matters to you: You’ll keep ice cream, frozen entrées, or diagnostics solid for 24–36 h when the cooler is pre‑chilled and stays closed. Dry ice is wrong for products that must not freeze (many vaccines, certain biologics). In those cases, phase‑change packs at +5 °C hold the safe range without DG paperwork.

Small pack of dry ice vs. gel/PCM—what should you pick?

Details: Dry ice delivers ultra‑cold −78.5 °C performance and high cooling capacity. PCMs (phase‑change materials) hit a target melt point like −20 °C or +5 °C and avoid dangerous‑goods labels. Gel packs hover near 0 °C for basic chilling. Choose based on the temperature your product actually needs.

Use case	Dry ice (small pack)	PCM (e.g., −25 °C / +5 °C)	What it means for you
Keep ice cream rock‑hard	✅ Best	❌ Too warm	Deep‑freeze for DTC and day‑plus lanes
Diagnostics < −20 °C	✅ Works	✅ Works	Pick DG (dry ice) vs non‑DG (PCM)
2–8 °C meds	❌ Too cold	✅ Best	Avoid freezing risk and DG handling

Practical tips and suggestions

Grocery or meal kit: Use a small pack of dry ice near the frozen zone; add +5 °C PCM near chilled items to prevent over‑freezing.
Short flights: Stay ≤ 2.5 kg (5.5 lb) total, use a vented rigid case, and mark the net kg on the outside.
Power outage: Stage a small pack of dry ice in a vented hard cooler; check every 12–18 h and add regular ice to stretch hold time.

Real‑world case: A bakery shipped frozen croissants using ~4 lb dry ice in a 24‑qt cooler with a barrier sheet and void fill. After 28 h in mild weather, the order arrived solid‑frozen, labels intact, vents open.

How do you pack a small pack of dry ice safely?

Direct answer: Pre‑chill, wrap, place, fill voids, vent, and label. Wrap blocks in paper to slow loss. Put dry ice on top to keep items frozen; on bottom with a barrier to keep them just cold. Keep lids closed and never seal airtight. Mark “Dry ice/Carbon dioxide, solid” and the net kg when shipping.

Explain it like a friend: Think of dry ice as a portable ultra‑freezer that breathes out CO₂. You want that gas to escape and the cold to sink around your payload. A simple paper wrap slows sublimation. A thin cardboard barrier prevents label scuffs and “freezer burn.” Fill voids so warm air can’t pool. Shade the shipper, and vent the gasket or drain.

Small pack of dry ice—step‑by‑step checklist

Detailed steps:

Pre‑chill the cooler 2–12 h (or use sacrificial ice).
Wrap the small pack of dry ice in newspaper or a paper bag.
Place & barrier: top to freeze; bottom to chill; add a thin barrier layer.
Fill voids with paper to cut air space.
Vent the container—never airtight; leave a path for CO₂ to escape.
Mark & weigh: “Dry ice / Carbon dioxide, solid,” UN1845, and net kg.

Packing element	Good practice	Why it matters	For your shipment
Wrapping	Newspaper/towel wrap	Slows sublimation; safer handling	Longer life; fewer scuffs
Placement	Top to freeze; bottom to chill	Uses natural cold airflow	Tailor to product risk
Venting	Gasket or drain left open	CO₂ must escape	Avoids pressure damage

Can you fly with a small pack of dry ice?

Direct answer: Yes—up to 2.5 kg (5.5 lb) per passenger with airline approval, in a vented package marked UN1845 with the net kg. Air cargo uses IATA PI 954 and Class 9 labeling; domestic ground in the U.S. generally follows 49 CFR 173.217 packaging and marking.

What this means for you: You can carry a small pack of dry ice on a flight if you vent the container and write the weight. For air cargo, carriers publish simple checklists—use them as your final pre‑tender audit. For mixed loads, add gel packs to extend cooling without increasing dry ice weight.

Airline & shipper quick‑check

Passenger flights: ≤ 2.5 kg per person; package vented and marked.
Air cargo: Class 9 label, UN1845, proper shipping name, net kg, vented per PI 954.
UPS Ground (U.S.): Not regulated as hazardous for domestic ground, yet packaging/marking rules still apply.

How much small pack of dry ice do you need?

Direct answer: Start with 5–10 lb per 24 h in a typical insulated cooler. Scale with volume, ambient heat, and lid openings. Blocks last longer than pellets; wrapping slows sublimation.

Why this works: Many supplier charts and field tests align near ~2%/hour loss under common conditions. Insulation quality, fill ratio, and sun exposure move the number. Validate on your lane with a data logger, then right‑size by ±20%.

Mini‑calculator: small pack of dry ice (rule of thumb)

# Inputs: hours_needed, container_quality (1=soft, 2=basic hard, 3=premium),

# ambient (1=cool shade, 2=mild/room, 3=hot sun),

# load_state (1=pre-frozen, 2=chilled)

base_rate = 0.30 # lb/hour ~7.2 lb/day midpoint of the 5–10 lb/24h rule
container_factor = {1:1.4, 2:1.0, 3:0.75}[container_quality]
ambient_factor = {1:0.8, 2:1.0, 3:1.3}[ambient]
load_factor = {1:0.9, 2:1.1}[load_state]

pounds = hours_needed * base_rate * container_factor * ambient_factor * load_factor
# Round up; for passenger flights cap total at 5.5 lb.

Example: 24 h, basic hard cooler, mild ambient, pre‑frozen load → ~6.5 lb → buy 7–9 lb for buffer.

Cooler size	24 h plan	36 h plan	What it means
12–20 qt	5–8 lb	8–12 lb	True “small pack” territory; pre‑chill helps
24–30 qt	7–10 lb	10–15 lb	Minimize openings; wrap blocks
45–50 qt	12–18 lb	18–25 lb	Consider two blocks + void fill

When should you not use a small pack of dry ice?

Direct answer: Skip dry ice when products are sensitive to freezing (many 2–8 °C vaccines), when packaging would be airtight, or when rooms/vehicles are poorly ventilated. Use +5 °C PCMs for 2–8 °C and −20 °C/−25 °C PCMs for frozen lanes that must avoid DG handling.

Why it matters: You’ll reduce refusals, simplify returns, and improve recipient safety. −25 °C PCM often matches overnight frozen performance without CO₂ off‑gassing or UN1845 labels—ideal for frequent air moves.

Choose by lane—small pack of dry ice vs. −25 °C PCM

Goal	Best choice	Why	Your move
Overnight, < −15 °C	Dry ice or −20 °C PCM	Both hit frozen; DG vs. non‑DG tradeoff	If flying often, trial PCM
24–48 h, < −20 °C	−25 °C PCM	Reusable; airline‑friendly	Charge packs; validate
≥ 48 h, deep‑frozen	Dry ice	Colder; higher energy density	Apply UN1845 + PI 954

2025 developments and trends: small pack of dry ice

Trend overview: Carriers refreshed dangerous‑goods checklists and reiterated UN1845, net‑kg marking, and venting. The 2.5 kg passenger cap remains. Meanwhile, sub‑zero PCM options expanded as practical “dry‑ice substitutes” for some lanes. Expect more hybrid packouts: small pack of dry ice + PCM sleeves to balance performance, cost, and compliance.

Latest progress at a glance

Carrier job aids: 2025 checklists clarify label placement and acceptance steps.
Stable passenger rules: The 2.5 kg limit with venting continues across airlines.
PCM growth: −25 °C gels reduce refusals and simplify returns for common overnight routes.

Market insight: Demand for small‑format frozen shipping remains high across DTC food, diagnostics, and specialty pharma. Companies increasingly select non‑DG PCMs when “frozen enough” is acceptable, reserving dry ice for deep‑frozen or 48 h+ lanes.

Frequently Asked Questions

Q1: How long does a small pack of dry ice last?
Plan 5–10 lb per 24 h in a hard cooler. Pre‑chilling and fewer openings extend life.

Q2: Can I fly with a small pack of dry ice?
Yes. ≤ 2.5 kg (5.5 lb) per passenger with airline approval, vented package, and net kg marked.

Q3: Do I need a DG declaration for air cargo?
Often no for dry ice used only as a coolant; labels/marks still required (UN1845, Class 9, net kg). Check the operator job aid.

Q4: Blocks or pellets for a small pack of dry ice?
Blocks last longer; pellets chill faster but sublimate sooner. Wrap either to slow loss.

Q5: What’s safer for 2–8 °C?
Not dry ice. Use +5 °C PCMs and proper conditioning to avoid freezing.

Summary and recommendations

Key points: A small pack of dry ice is ideal for 24–36 h frozen control when you pre‑chill, wrap, vent, and label. Follow UN1845/Class 9 and net‑kg rules for air; cap baggage at 2.5 kg. Use −25 °C PCMs when you want frozen control without DG complexity.

Next steps (CTA):

Use the mini‑calculator to size your small pack of dry ice.
Print our packing SOP and airline checklist for your team.
Pilot with a data logger, then tune ±20%.
Talk to a Tempk specialist for lane‑by‑lane coolant plans.

About Tempk

We engineer validated packouts for frozen, chilled, and CRT shipments. Our team blends thermal modeling with qualified shippers and the right coolant—small pack of dry ice or −25 °C PCM—to hit target temperatures with fewer touchpoints and lower landed cost. We focus on evidence‑based SOPs and fast pilot‑to‑scale for DTC food, diagnostics, and specialty pharma.