<P> Isopropyl rubbing alcohols contain from 50% to 99% by volume of isopropyl alcohol, the remainder consisting of water . Boiling points vary with the proportion of isopropyl alcohol from 80 ° C (176 ° F) to 83 ° C (181 ° F); likewise freezing point vary from − 32 ° C (− 26 ° F) to − 50 ° C (− 58 ° F). Surgical spirit BP boils at 80 ° C (176 ° F). </P> <P> Naturally colorless, products may contain color additives . They may also contain medically - inactive additives for fragrance, such as wintergreen oil (methyl salicylate), or for other purposes . </P> <P> To prevent against alcohol abuse in the United States, all preparations classified as Rubbing Alcohols (defined as those containing ethanol) must have poisonous additives to limit human consumption in accordance with the requirements of the US Treasury Department, Bureau of Alcohol, Tobacco, and Firearms, using Formula 23 - H (8 parts by volume of acetone, 1.5 parts by volume of methyl isobutyl ketone, and 100 parts by volume of ethyl alcohol). It contains 87.5--91% by volume of absolute ethyl alcohol . The rest consists of water and the denaturants, with or without color additives, and perfume oils . Rubbing alcohol contains in each 100 ml more than 355 mg of sucrose octaacetate or more than 1.40 mg of denatonium benzoate . The preparation may be colored with one or more color additives . A suitable stabilizer may also be added . </P> <P> Product labels for rubbing alcohol include a number of warnings about the chemical, including the flammability hazards and its intended use only as a topical antiseptic and not for internal wounds or consumption . It should be used in a well - ventilated area due to inhalation hazards . Poisoning can occur from ingestion, inhalation, absorption, or consumption of rubbing alcohol . </P>

What is the difference between 70 and 99 isopropyl alcohol