Acetone is a common organic solvent recognized for its ability to dissolve various substances, most familiarly as the primary active ingredient in many nail polish removers. The colorless liquid is also widely used in industrial settings for cleaning, thinning resins, and preparing surfaces. If you are considering using a plastic container to hold this solvent, the answer depends entirely on the specific type of plastic involved. Using the wrong plastic can result in immediate softening, deformation, or even the complete dissolution of the container.
What Makes Acetone a Powerful Solvent
Acetone’s effectiveness as a solvent stems from its unique molecular structure, classifying it as a ketone. This configuration gives the molecule a polarity, meaning it has both a slightly positive and a slightly negative end, allowing it to interact readily with a wide range of materials. The liquid acts as a solvent by weakening the intermolecular forces that hold the long polymer chains of plastic together. When the plastic is exposed to acetone, the solvent molecules insert themselves between these chains, pulling the structure apart. This physical dissolution causes the plastic to lose its rigidity, swell, or liquefy.
Identifying Plastics That Acetone Damages
Many common plastics are highly susceptible to damage from acetone, often with immediate and dramatic results. One of the most vulnerable materials is Polystyrene (PS), identified by the recycling code #6, which includes Styrofoam and some clear disposable containers. Acetone causes Polystyrene to dissolve rapidly into a sticky residue.
Other plastics that should never be exposed to acetone include Polyvinyl Chloride (PVC, code #3) and Polycarbonate (PC), which is often grouped under the “Other” recycling code #7. Exposure to acetone will typically cause these materials to soften, cloud, or develop fine cracks, known as stress cracking, compromising their structural integrity. Even brief contact with thin plastic items made from these susceptible materials can lead to permanent damage and container failure, potentially causing a hazardous spill. Acrylonitrile Butadiene Styrene (ABS), a common plastic in 3D printing and piping, also softens and deforms upon contact. When in doubt about a plastic’s composition, looking for the small triangular recycling symbol stamped on the bottom of the item is the quickest way to identify the material.
Materials Safe for Acetone Use
Fortunately, some widely available plastics and non-plastic materials exhibit strong resistance to acetone. The most common resistant plastic is Polypropylene (PP), which carries the recycling code #5 and is frequently used for caps, yogurt containers, and durable laboratory equipment. High-Density Polyethylene (HDPE), marked with the recycling code #2 and used for milk jugs and detergent bottles, is also generally safe for acetone use.
These plastics resist dissolution because their chemical structures are not easily penetrated by the acetone molecules. The dense, non-polar nature of the polymer chains in PP and HDPE resists the solvent’s attempt to pull them apart. For absolute safety, non-plastic alternatives are the preferred choice, including glass, ceramic, and stainless steel. These materials are chemically inert and will not be affected by the solvent, making them ideal for long-term use or storage.
Handling Acetone Safely and Disposal Tips
Regardless of the container material chosen, handling acetone requires specific safety precautions due to its properties. Acetone is highly volatile and flammable, meaning it can easily ignite from a spark or heat source, even at room temperature. Always ensure adequate ventilation when working with the solvent to prevent the buildup of vapors and reduce the risk of inhalation. Avoid prolonged contact with the skin, as acetone can cause dryness and irritation by dissolving natural skin oils.
When it is time to dispose of used acetone, never pour the liquid down a household drain. For small, household quantities, you can allow the liquid to evaporate completely outdoors in a safe, open container away from any ignition sources. Larger quantities must be collected and disposed of according to local hazardous waste guidelines.