Active -inactive,Experienced-inexperienced are antonyms, but why Flammable and Inflammable are synonyms?

Question

This confusion may lead to fire hazards.Somebody may think inflammable means it won't catch fire and start smoking.

Answer 1

You're right there may be confusion and that is why the standard is to use the word flammable. The standard use for items that cannot catch fire is nonflammable.

Many authorities also use pictograms to convey flammability such as a flame or a flame with a circle and slash