|MadSci Network: Chemistry|
Does Isopropyl Rubbing Alcohol leave a toxic residue after evaporation? I got some on my hands when cleaning with it, and after it evaporated, I grabbed some food and ate without washing my hands first. Is that bad? I just assumed the Isopropyl Alcohol cleaned my hands and was safe after evaporation.
When working with any chemical, you should have access to and consult the appropriate Materials Safety Data Sheet (MSDS). You can find isopropanol MSDSs online. For example, take a look at this one, and this one.
With regard to skin contact with isopropanol, these sheets say the following: "Wash hands thoroughly after handling.", "May cause irritation with redness and pain. May be absorbed through the skin with possible systemic effects.", "Immediately flush skin with plenty of water for at least 15 minutes. Call a physician if irritation develops.", and "Thoroughly wash exposed area for at least 15 minutes. Remove contaminated clothing. Launder contaminated clothing before reuse. Get medial attention if irritation persists."
With respect to the potential for toxic residues, the first MSDS says, "Small quantities of peroxides can form on prolonged storage. Exposure to light and/or air significantly increases the rate of peroxide formation. If evaporated to a residue, the mixture of peroxides and isopropanol may explode when exposed to heat or shock."
Finally, with respect to handling isopropanol, both sheets suggest wearing gloves: "Protective gloves: Rubber, neoprene, PVC, or equivalent.", and "Wear impervious protective clothing, including boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. Neoprene and nitrile rubber are recommended materials."
So, the issue of concern may be less about any residue left behind after the isopropanol has evaporated and more about a concern that isopropanol can be absorbed through the skin. When handling isopropanol, wear gloves, minimize skin contact, and wash your skin where you have had contact with isopropanol.
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