Which plastic is described as lightweight and resistant to organic solvents?

• A. HDPE
• B. PVC
• C. PP
• D. FRP

Answer: (A)

This item tests how a plastic’s weight and its ability to stand up to organic solvents influence material choice. High-density polyethylene is lightweight due to its low density, and it offers broad resistance to many organic solvents and hydrocarbons because of its simple, nonpolar polymer structure. That combination—being light and chemically resistant—makes it a common go-to for containers and parts that will contact solvents.

PVC can resist many chemicals but is susceptible to certain organic solvents like ketones and aromatic hydrocarbons, which limits its universal solvent resistance. Polypropylene also has good solvent resistance, but its performance isn’t as broad or predictable across a wide range of solvents as HDPE. Fiber-reinforced plastics’ resistance depends on the resin system used and can also be heavier or less uniformly resistant to solvents, so it isn’t inherently the best match for “lightweight and resistant to organic solvents” in a general sense.

So, the best fit for a plastic that is both lightweight and resistant to organic solvents is HDPE.