Substance – la sustancia

To remember that substance is pronounced soos-tahn-syah (sustancia) in Latin American Spanish, use the following mnemonic:

After using a strange chemical substance on him, he sues the tanning salon when he sees a (sustancia) serious problem.

After using a strange chemical substance on him, he sues the tanning salon wen the active (sustancia) ingredient turns him blue.

Sustancia is feminine, so it's la sustancia. Imagine a lady stepping in a weird substance.