HydroFreeze & HydroFreeze+ Ice Packs

From: £0.42 each

What is HydroFreeze™

HydroFreeze™ and HydroFreeze™+ are our ice packs containing a unique food safe formula, designed to enable safer shipping of frozen goods. They work in the same way as dry ice, but are much safer as, unlike dry ice, HydroFreeze™ products are not classed as hazardous goods when shipping, and they do not require any specialist handling.

Both versions of HydroFreeze™ can maintain temperatures at -20°C for an extended period of time. The formula consists of only food approved, natural ingredients, found in your everyday life!

  • As with all ice packs, the colder the freezer the faster they will freeze. Ideally, HydroFreeze™ products should be frozen below -30°C.
  • They are a great dry ice alternative as they are FSA certified food safe, non-toxic and not classed as hazardous goods. You will not have to use the same HAZMAT labelling as with dry ice, or use a specialist courier to ship your goods.
  • HydroFreeze™ ice packs do not sublimate (“melt”) so you only need to buy what you need, and not account for excess. Pack and freeze to suit your demands.

Try a sample of our HydroFreeze™ & HydroFreeze™+ Ice Packs for free to help you decide if these are the right packs before you commit to a full order. This is a one-time service per customer with up to 3 samples per basket.

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What is the difference between HydroFreeze™ and HydroFreeze™+?

  • HydroFreeze™ is a formula designed to phase change at -20°C. When frozen correctly and packed in a good quality insulated box, these ice packs can be used to hold frozen food at a temperature of below -12°C for approx. 24 hours.
  • HydroFreeze™+ is our newly developed gel formulation of the previous product and is designed to enable shipping of frozen goods for longer transit times – they will hold food at -20°C for approx. 24 hours or -15°C for approx. 36 hours.

Like the regular HydroFreeze™ ice packs, the new HydroFreeze™+ ice packs phase change at -20°C and can hold food at around that temperature, but where the  HydroFreeze™+ formula really excels is in its longevity. These ice packs will absorb a great deal more energy before they completely freeze, so will need to be in a powerful freezer or will take a longer period of time to freeze. However, once they are frozen and packed inside a suitable insulated container they will hold-20°C for approx. 24 hours or -15°C for approx. 36 hours.

HydroFreeze™ and HydroFreeze™+ can maintain temperatures at -15°C, however HydroFreeze™+ can hold that temperature for an extended period of time. Both of these products have been developed with safety, quality, performance and cost in mind, and consist of only food approved ingredients.

HydroFreeze™ and HydroFreeze™+ are produced in our state-of-the-art manufacturing facility in High Wycombe, Buckinghamshire, with the capacity to cater for all users looking for a safer and more economical solution to sending frozen goods.

Currently using Dry Ice?

Dry ice (solid CO2) is currently the most common consumable used for the shipping of frozen products; it maintains sub-zero temperatures through the process of sublimation – i.e. converting directly from a solid to a gas. Dry ice is classified as a miscellaneous hazard (Class 9) during transportation by DOT and IATA.

Hazards associated with dry ice include risk of explosion and suffocation in an enclosed space, and risk of severe frostbite injury when handled. Dry ice is so cold it will freeze the blood inside your skin if handled with bare hands. For these reasons, many carriers have now restricted or prohibited the distribution of parcels containing dry ice, and the couriers that do still accept it will apply a surcharge to the shipping cost.

HydroFreeze™ and HydroFreeze™+ eliminate these hazards and offer a safer and competitive alternative – think of it as a regular ice pack… just a cooler version of it! Please note, these ice packs are not a dry ice substitute, they are a safe dry ice alternative.

Why not use regular water/gel ice packs?

Regular water/gel ice packs phase change at 0°C (the freezing point of water) so once packed inside your insulated box, they will sit at around 0°C while changing from a solid back to a liquid. These regular water/gel ice packs should only be used for shipping chilled food as they phase change at 0°C – not cold enough for frozen food, but they are perfect for refrigerated goods.

HydroFreeze™ products have a phase change point of -20°C, which means they hold that temperature while changing from a solid back to a liquid – and hold the food products inside the insulated box at around the same temperature.

Recommended Pre-conditioning of HydroFreeze™ & HydroFreeze™+HydroFreeze™ products should be pre-conditioned in a sufficiently powerful freezer capable of maintaining temperatures below -35°C; however, it is advisable to use the coldest freezer setting you have available.

Recommended Freezing/Storage:


  • -25C for at least 48 hours
  • -30C for at least 24 hours
  • -35C for at least 18 hours
  • -40C for at least 12 hours
  • -45C for at least 8 hours


  • -30C for at least 36 hours
  • -35C for at least 24 hours
  • -40C for at least 18 hours
  • -45C for minimum of 12 hours

IMPORTANT: Ensure HydroFreeze™ products are fully solid before use; if packs are slushy, do not use – allow additional time in the freezer to harness their full power!

* Freeze times are largely dependent on the freezer temperature and the quantity that is being frozen at that particular time (i.e. a pallet load will take considerably longer to fully prepare compared to a single pack). Ensure sufficient cold air circulation around the products for efficient freezing and be aware they will take longer to freeze than normal water/gel ice packs.

Safety and Disposal Instructions

  • HydroFreeze™ products are a non-toxic food approved formula, which is safe under normal use.
  • Do not ingest. Avoid contact with eyes and skin.
  • HydroFreeze™ products can be safely disposed of down the sink and flushed away with running water.
  • Emptied plastic pouches can be recycled with other plastics (#4) – check local recycling capabilities.
  • Material safety datasheet

For more information

Call 01494 530182 or email us at sales@hydropac.co.uk

“UK Patent Application No. 2201805.8 and International Patent Application No. PCT/GB2023/05297”

So What are the Benefits of Using HydroFreeze™ and HydroFreeze™+

  • FSA Approved – FSA approved, non-toxic formula which is safe under normal use
  • Eco-friendly – HydroFreeze™ ice packs tick the eco box – the formula can be safely poured away down the sink and flushed away with water. The emptied plastic pouches can then be recycled alongside other plastics (#4) – check your local council’s facilities first.
  • Reusable! HydroFreeze™ products can be re-frozen and reused with minimal impact of its effectiveness.
  • Reduced expenditure – pay for only what you need. Dry ice naturally sublimates during storage therefore additional amounts will need be purchased to account for sublimation losses – HydroFreeze™ products do not have this issue; any surplus HydroFreeze™ products can be safely stored in your warehouse until next needed.
  • Increased operational flexibility – dry ice must be used ASAP otherwise loss will occur through sublimation. HydroFreeze™ products can work around your packing schedule – freeze and pack to suit your demands.
  • Reduced admin – dangerous goods forms are a thing of the past when you switch to HydroFreeze™ products.
  • Increased courier choices – parcels containing HydroFreeze™ products can be safely delivered by multiple carriers.
  • Increased safety – HydroFreeze™ products eliminate many of the hazards associated with the handling and storage of dry ice, meaning a safer environment for your employees, package handlers and customers.

Differentiators between HydroFreeze™ products & dry ice

Dry Ice HydroFreeze™+ Water/Ice
Melting/Sublimation Point -78.5°C -20°C 0°C
Amount of energy

(Below -15C)*

571.3 347 136.5
Classed as Hazardous Goods Yes No No
Suitable for Frozen Goods Yes Yes No
Cost Per Kg From £1.00+ From £0.86 From £0.42

* Assuming theoretical start temperature of -80°C and 1kg of each


Dry Ice HydroFreeze™+ Water/Ice
Melting/Sublimation Point -78.5°C -20°C 0°C
Amount of energy

(Below -15C)*

571.3 347 136.5
Classed as Hazardous Goods Yes No No
Suitable for Frozen Goods Yes Yes No
Cost Per Kg From £1.00+ From £0.86 From £0.42

* Assuming theoretical start temperature of -80°C and 1kg of each

Useful Test Graph

FSA Temperature Control Guide Download Now