Here's what rhymes with preservative.

Consider these alternatives

thimerosal / social formaldehyde / side fungicide / side flavoring / favoring benzoic / heroic antimony / testimony fluoride / fluorite electrolytes / rights salts / towards acetone / known monosodium / sodium phthalates / states nitrite / right sorbic / aortic benzoate / state flavouring / favoring chelation / relation insecticide / side antibacterial / bacterial glutamate / late beryllium / delirium stain / main peroxide / dioxide