Which plastic is used for alkaline storage?

• A. Polyethylene
• B. Polypropylene
• C. Polycarbonate
• D. Polystyrene

Answer: (A)

This question tests how plastics hold up when exposed to alkaline solutions. When storing bases like NaOH or KOH, you want a container that won’t be attacked, dissolved, or degraded by the base.

Polyethylene fits that requirement very well. It resists bases strongly, so it stays stable, swells little, and maintains its integrity even with concentrated alkaline solutions. It’s also inexpensive and widely available as bottles and drums for storing bases, which is why it’s the default choice for alkaline storage.

Other plastics don’t fare as well under strong bases. Polycarbonate can suffer alkaline attack, leading to hazing or embrittlement. Polystyrene is more prone to damage or swelling with bases at higher temperatures. Polypropylene is resistant to bases too, but in many lab and storage contexts polyethylene is preferred for its exceptional base compatibility and practicality.

So the material best suited for alkaline storage is polyethylene.