Cushion fragile shipments, won't dilute ice baths or damage samples. They remain frozen longer than regular ice without the melting mess. May be refrozen and reuse, withstands pressure of 60 lb per square inch for 5 minutes or longer. Refrigerant contains neutral pH distilled deionized water and proprietary materials certified by the US Food and Drug Administration as food grade chemicals. -1 degree C / +30 degree F. Individual Packets.