A sulfate salt is a metal or ammonium ion paired with the sulfate ion, SO4 2-. Most of them are crystalline solids that dissolve readily in water, and a lot of them come in hydrate forms, meaning water molecules are locked into the crystal structure itself. That's why you'll see products labeled pentahydrate or heptahydrate rather than a plain anhydrous name. Beyond that shared structure, the metal in charge decides everything else. Magnesium sulfate heptahydrate is the same compound as Epsom salt and about as benign as chemistry gets. Copper sulfate is a recognizable blue crystal that's also a registered fungicide and algicide. Ferrous and ferric sulfate are common water treatment coagulants. Cobalt and nickel sulfate carry their own toxicity profiles that plain magnesium or sodium sulfate simply don't have, so the SDS is where the real differences show up, not the family name.
COMMON APPLICATIONS
Fertilizer, especially ammonium sulfate for nitrogen and sulfur in alkaline soils. Fungicide, algicide and root control with copper sulfate. Water treatment coagulation with ferrous and ferric sulfate. Buffers, reagents and analytical standards across the board. Desiccants and drying agents with anhydrous sodium and magnesium sulfate. Electroplating baths with nickel and cobalt sulfate. And of course, magnesium sulfate heptahydrate as the Epsom salt used in bath soaks and horticultural supplementation.
GRADES EXPLAINED
Lab Grade is the largest group by product count, solid everyday purity with no formal monograph attached. ACS Reagent Grade meets American Chemical Society limits for analytical methods. USP Grade meets pharmacopeia standards, and FCC Food Grade meets food chemical standards, which together cover the small number of sulfates certified for food, drug or supplement use. Reagent Grade covers premixed molar and normal solutions built for specific procedures.
TYPES & GRADES AT A GLANCE
WHY BUY FROM LAB ALLEY
256,000+ customers already order their chemicals and reagents from Lab Alley.
99.5% of orders ship within 1 to 2 business days, and 98.9% inventory accuracy means the grade you see in stock is the grade that ships.
SDS and COA are available online for every sulfate salt, and select magnesium sulfate products carry Kosher certification; check each product page for which applies.
Related: See our Chlorides and Sulfuric Acid collections, or browse all Salts.