Not all PCMs are created equal. ThermApparel’s PCM is USDA-certified non-toxic and biodegradable. We chose it because it outperforms paraffin, salt hydrates, gel, and ice in several areas like its long-term stability, is sourced from recyclable materials, won’t get you wet or burn your skin, and contains no dangerous oils or hard-to-clean paraffin waxes. Our lightweight and flexible PCM Cooling Packs are reusable, making them able to be recharged over and over again. Read more info about PCM and see our safety data sheet for more info.