Arrange the following items as per their Toxicity Rating for humans from high to low value:

From high to low toxicity the order runs nicotine, mercury salts, caffeine, household cleansers and finally table sugar.

Statement 4, nicotine, ranks most toxic as a very small dose can be lethal.

Statement 5, mercury salts, come next as highly poisonous heavy-metal compounds.

Statement 1, caffeine, is moderately toxic and harmful only in large amounts.

Statement 3, household cleansers, are slightly toxic and cause harm chiefly on misuse.

Statement 2, table sugar, is practically non-toxic and sits at the bottom of the scale.

Toxicity rating compares the dose needed to cause harm, so a smaller lethal dose means higher toxicity.