potassium lye
ChemsA liquid form of potassium hydroxide. It is highly corrosive; handle with care.

A practical guide to what matters across CDDA’s scavenging, crafting, equipment, and specialist systems.
Introduction history determines newest order. Undated objects follow dated additions; download dates do not make an object new.
A handful of almost-weightless residue left after the burning of some substance.
A flammable gas that explodes under pressure. Combined with oxygen, acetylene makes a great welding gas.
A handful of highly carcinogenic white powder that can be readily polymerized into a whole bunch of useful water-soluble gels.
Clear flakes of processed seaweed that can be dissolved in boiling water to create a very sturdy, temperature-resistant gel. Not only is it good for making gels to separate molecules by size, but it's a great cheat ingredient to make sure your jellies set properly.
Ammonium hydroxide, a common household cleaning agent.
A handful of soft, colorless powder with a sharp pungent odor, also known as butter of antimony. It's a catalyst for polymerization, hydrocracking, and chlorination reactions, and has some other niche uses.
Single base smokeless gunpowder intended for use in artillery propelling charges.
A handful of white, odorless powder with a slightly salty alkaline taste. Often used in baking as a leavening agent, and has many other niche uses. Also known as sodium bicarbonate.
A fragile, slightly quivering organ for the production and storage of honeybee venom. You could extract some very useful chemicals from it with the right know-how, but only if you hurry.
A colorless, highly flammable liquid with a sweet odor, one of the elementary petrochemicals. Being used primarily as a precursor to the manufacture of chemicals with more complex structure, it's a major industrial chemical, but finds limited use in consumer items because of its toxicity.
Biogas gathered from anaerobic digester system, can be used in biogas cooker.
Bird droppings, feathers, and soiled bits of rubbish.
A handful of chromium oxide. This substance, typically known as the only stable green pigment for paints, is also a mild oxidizer, which can be mixed with aluminum powder to make thermite for welding. If one had access to a CVD machine and a laboratory worth of reagents, they might be able to produce very durable ceramic layers.
A handful of powdered colorful cloth dye, which can be used to dye many fabrics if combined with water and some mordant.
Composition B is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades, and various other munitions.
The burnt remains of a person or animal.
A fresh cow pie; this could probably be used to make some great fertilizer.
A high-strength ethanol solution mixed with denatonium benzoate to make it impossibly bitter to drink, so as to avoid pre-apocalyptic regulations on ethanol. Intended for use in alcohol-burning stoves and as a solvent.
A popular pre-Cataclysm washing powder.
Dimethyl sulfoxide, or DMSO, is a common and important aprotic solvent, capable of dissolving a huge range of things. It has the unusual property of being absorbed very quickly through the skin, causing a garlic flavor in the mouth, even if it touched your arm.
Droppings from a canine.
Extremely pure alcohol suitable for use as a component in chemical reactions. You could also water it down and drink it, or use it as fuel in an alcohol-burning stove.
A useful industrial solvent, and the first inhalative anesthetic in widespread use. Its uncomfortable side effects and tendency to explode caused it to fall out of favor decades ago in the developed world. If you can't get the good stuff, however, it might make a passable substitute.