Product Overview
Ferric Chloride 40% is an aqueous solution of iron(III) chloride (CAS 7705-08-0), offered in Water Treatment grade as a dark reddish-brown to near-black liquid. It is the workhorse coagulant of municipal and industrial water treatment and the standard etchant for copper-clad printed circuit boards. Buyers range from wastewater operators dosing a clarifier to electronics shops running a PCB etching line to labs that need a dependable iron(III) source on the bench.
We distribute it in pack sizes from 1 quart bottles up to 330 gallon IBC totes, all available to order from our Taylor, Texas warehouse. As a corrosive Class 8 hazmat, every order is packed and papered by a team that ships regulated chemicals daily.
Why This Concentration
A 40% solution puts ferric chloride near the practical top of its working range: enough active iron(III) per gallon to keep coagulant dose volumes and freight cost down, while still pouring and pumping as a stable liquid. Water treatment operators typically meter it neat or cut it to a target strength at the point of injection; if your dosing skid or etch bath calls for a lower working concentration, diluting down from 40% with water is straightforward and lets one drum cover multiple setpoints.
The trade-off is handling. At this strength the solution carries the signal word Danger, causes severe skin burns and eye damage (per the product's GHS classification) and may be corrosive to metals (per the product's GHS classification). Choose 40% when your process consumes real volume — coagulation, etching, pigment work — and your site is already set up for corrosive liquid transfer. For occasional bench use, the quart size limits the quantity you have to store and neutralize.
Chemical Profile
Ferric Chloride 40% is a dark reddish-brown to near-black liquid with a slight hydrochloric acid odor, clear and free of visible sediment. The dissolved salt is iron(III) chloride, formula FeCl3, molecular weight 162.20, CAS 7705-08-0. The product is made to a 38–42% FeCl3 assay, with 40% as the nominal target — “40%” and “38–42%” describe the same material. Specific gravity runs 1.380–1.490 — noticeably heavier than water, which matters when sizing containment and calculating freight weight per gallon. It is miscible with water in all proportions, so in-line dilution to a working strength presents no solubility limit.
Water Treatment Applications
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Water and wastewater treatment.Ferric chloride is a primary coagulant: dosed into raw water or wastewater, the iron(III) ion hydrolyzes and destabilizes suspended solids so they floc and settle. Plants use it for turbidity removal, phosphorus precipitation and sludge conditioning.
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PCB etching.In electronics manufacturing, ferric chloride solution dissolves exposed copper from printed circuit boards, leaving the masked traces behind. It remains the most common etchant for prototype and small-run PCB work.
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Pigment production.Iron(III) chloride serves as a precursor in the manufacture of iron-based pigments.
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Catalysis.Ferric chloride acts as a Lewis-acid catalyst in a range of organic synthesis reactions.
Handling & Storage
Treat this product as a corrosive liquid at every step. The signal word is Danger. It causes severe skin burns and eye damage, causes serious eye damage, causes skin irritation, is harmful if swallowed, may be corrosive to metals and is harmful to aquatic life with long lasting effects (per the product's GHS classification). Wear chemical-resistant gloves and goggles at minimum and work with ventilation adequate to avoid breathing vapors — the solution gives off a slight hydrochloric acid odor.
Store it cool, dry and out of direct sunlight in HDPE or glass; because the solution may be corrosive to metals (per the product's GHS classification), keep it away from unlined steel containers, fittings and drip trays. Keep it segregated from strong bases and reducing agents. Given the aquatic hazard, contain spills and keep the material out of drains and waterways.
Hazmat & Shipping
Ferric Chloride 40% ships as regulated hazmat under UN2582, proper shipping name "Ferric chloride, solution" Hazard Class 8 (corrosive), Packing Group III (per 49 CFR 172.101). We pack quarts and gallons in UN-rated packaging with the required markings and labels and prepare drums and totes with the shipping papers Class 8 ground freight requires. This shipping and handling guidance is reviewed by Andre Taki, DOT Hazmat Specialist.
Documentation
A Safety Data Sheet is included with every order, available in English, Spanish, French and Japanese — useful for multilingual crews and cross-border compliance files. A Water Treatment Data Sheet is available for process and engineering review and a lot-specific Certificate of Analysis is available for orders where your quality system requires traceability to the shipped lot.
Why Buy from Alliance Chemical
One supplier covers your whole range on this product: the same Water Treatment grade Ferric Chloride 40% is offered from 1 quart bottles for the bench up to 55 gallon drums and 330 gallon IBC totes for continuous dosing, each with SDS, TDS and lot-specific COA support behind it. Alliance Chemical has operated since 1998 and has served more than 55,000 customers, shipping corrosives like this one under a working DOT hazmat program rather than treating regulated freight as an exception. If you're scaling from pilot dosing to full plant feed, we can quote the next container size up without a supplier change.
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