What materials have a melting point between about 17 and 25 C and are relatively safe?

heptadecane mp ~21C, caprylic acid 16-17C, DMSO (dimethylsulfoxide) 18.5C. coconut oil mp~24-25C. As far as toxicity goes, heptadecane is probably like gasoline/diesel. caprylic acid is a fatty acid slightly corrosive avoid eye or skin contact, DMSO not bad by itself, but readily absorbed through skin and can take toxic chemicals through your skin, so have a care if you are using it around other chemicals. Coconut oil, well, people eat it on popcorn and cook with it, so it is probably the least toxic of everything I can think of. As with all things I advise you to look up these on a MSDS (material safety data sheet) for more info. Hope this helps. heptadecane mp ~21C, caprylic acid 16-17C, DMSO (dimethylsulfoxide) 18.5C. coconut oil mp~24-25C. As far as toxicity goes, heptadecane is probably like gasoline/diesel. caprylic acid is a fatty acid slightly corrosive avoid eye or skin contact, DMSO not bad by itself, but readily absorbed through skin and can take toxic chemicals through your skin, so have a care if you are using it around other chemicals. Coconut oil, well, people eat it on popcorn and cook with it, so it is probably the least toxic of everything I can think of. As with all things I advise you to look up these on a MSDS (material safety data sheet) for more info. Hope this helps.