Every refrigerant pack does the same fundamental job: it acts as a thermal mass, absorbing heat from its surroundings as it moves through a phase change — solid to liquid for ice and gel packs, or a tighter-controlled transition for engineered PCMs. The amount of cooling a pack can deliver, and for how long, comes down to its latent heat of fusion and how tightly its melting point is controlled. Plain water-based ice packs melt across a wide, sloppy temperature band and leave you with a bag of water. Early “blue ice” packs swapped water for glycol gel to fix the leakage problem, but glycol-based formulations are exactly the consumer-grade products now flagged with caution by the US FDA and Australia’s Therapeutic Goods Administration (TGA) — and despite the regulatory concerns, they’re rarely cheap once they reach the shelf.
Cryophase engineers around this with phase change material (PCM) formulations designed to hold a tighter melting band and a higher latent heat capacity than consumer-grade gels, translating to up to five times the usable cold-hold time per unit of mass. We manufacture across both reusable and disposable formats, so the choice comes down to your logistics model — recirculating an esky fleet, or running one-way disposable shipments — rather than a compromise on thermal performance.
The range spans several engineered formats, each solving a specific cold chain problem:
- Bubble-back gel packs (anti-freeze packs) use a sealed air-gap layer to slow heat transfer on one face, protecting payloads that can’t tolerate direct contact with sub-zero gel.
- Tuna gullet packs are a narrow-profile gel format built to be inserted directly into the body cavity of large fish, cooling from the core outward rather than relying on surface contact alone.
- Instant-activation packs rely on an endothermic reaction (rather than pre-freezing) to deliver cold within seconds — built for first aid and situations where there’s no time to plan ahead.
- Instant heat packs trigger an exothermic oxidation reaction on exposure to air, holding warmth for up to 20 hours.
- PCM gel bricks are formulated around a specific target melting point, giving pharmaceutical and food shipments a flat temperature plateau rather than a slow drift toward ambient.
Across the range, Cryophase functions as a single manufacturing source for commercial-grade refrigerants built for perishables, pharmaceutical specimens, and vaccine logistics — engineered to a spec, not just cold to the touch.