Product Overview
Sodium Bisulfite 40% is a ready-to-use aqueous reducing agent supplied in technical grade. The 40% concentration delivers sodium bisulfite (NaHSO₃) as a clear, colorless to light-yellow liquid — no on-site dissolving of dry powder, no dust control headaches and direct metering into your process line.
This solution is ordered by water treatment operators running dechlorination, textile processors managing bleach cycles and chemical manufacturers who need a consistent reducing agent feed. Alliance Chemical offers it across a wide size range — from 1-quart bottles for bench trials up to 330-gallon totes for continuous industrial dosing.
Why This Concentration
A 40% sodium bisulfite solution sits at the practical ceiling for aqueous concentration — strong enough that you ship meaningful reducing capacity per gallon, yet stable enough in storage that it won't crystallize out at normal warehouse temperatures. For the buyer, that means lower freight cost per pound of active ingredient compared to dilute solutions and no dissolution step compared to dry sodium bisulfite.
Technical grade is the standard industrial workhorse: it is specified for process chemistry, water treatment and manufacturing applications where a laboratory-certified assay is not part of the workflow. If your process does require a higher-purity designation with documented assay — analytical work, QC reference solutions, or procedures that call out an Technical — considerSodium Bisulfite 40% ACS Reagent Grade instead.
Chemical Profile
Sodium Bisulfite 40% is an aqueous solution of sodium hydrogen sulfite with the molecular formula HNaO₃S and a molecular weight of 104.06 g/mol (CAS 7631-90-5). The liquid is clear, ranging from colorless to light yellow and carries a slight sulfur dioxide odor — distinctive enough to notice at the drum but not overwhelming in a ventilated area. Its density falls between 1.32 and 1.35 g/cm³ at 20 °C, noticeably heavier than water, which matters when sizing pumps and calibrating volumetric feeders. The solution is fully miscible with water, making dilution and in-line blending straightforward.
Industrial Applications
Sodium bisulfite's value in industrial processes comes from its chemistry as a reducing agent — it donates electrons readily, which makes it effective at neutralizing oxidizers, scavenging dissolved oxygen and adjusting redox conditions across a range of operations.
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Water Treatment & Dechlorination— The single largest use. Municipal and industrial water treatment plants dose sodium bisulfite to quench residual chlorine in discharge water before it enters waterways. As a reducing agent, it reacts with free chlorine and chloramines rapidly, bringing residual levels down without adding problematic byproducts. Operators meter the 40% solution directly into the process stream using chemical feed pumps.
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Chemical Manufacturing— Serves as a reducing intermediate in the synthesis of dyes, pharmaceuticals and specialty chemicals. The liquid form simplifies reactor charging — pump a metered volume rather than weighing and dissolving a powder mid-batch.
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Textile Processing— Used in bleaching and dyeing operations as a reducing agent to strip residual oxidizers between process stages. Consistent concentration from the drum means repeatable dosing, which matters when color uniformity is the target.
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Photographic Processing— Acts as a reducing agent in developer solutions, where controlled reduction of silver halide crystals forms the image. Though a smaller-volume application today, it remains a standard chemistry in traditional darkroom work.
Handling & Storage
Sodium Bisulfite 40% carries aDangersignal word (per the product's GHS classification). The three hazard statements that govern handling are:H302— harmful if swallowed;H318— causes serious eye damage; andEUH031— contact with acids liberates toxic gas (per the product's GHS classification). That last point is the one most often overlooked on a loading dock: if this product contacts strong acids, it releases sulfur dioxide gas. Keep it physically separated from acid drums in storage and during transport staging.
Wear chemical splash goggles and chemical-resistant gloves as minimum PPE when handling. A face shield is warranted during any transfer operation where splashing is possible. Store in a cool, dry area away from direct sunlight. Use HDPE or glass containers — avoid bare metal, which can corrode on contact with the acidic solution. Keep away from strong oxidizing agents and strong acids to prevent incompatible reactions. Containers should remain tightly closed when not in use to limit sulfur dioxide off-gassing.
Hazmat & Shipping
Sodium Bisulfite 40% is a regulated hazardous material for transport. The DOT classification that governs every shipment:
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UN Number:UN2693 (per 49 CFR 172.101)
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Hazard Class:8 — Corrosive (per 49 CFR 172.101)
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Packing Group:III (per 49 CFR 172.101)
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Proper Shipping Name:Bisulfites, aqueous solutions, n.o.s. (Sodium bisulfite) (per 49 CFR 172.101)
Every outbound shipment from our Taylor, TX warehouse is prepared with the required hazmat shipping papers, markings and labels. Our team handles Class 8 corrosive shipments daily — this is routine work for us, not an exception.
Documentation
A Safety Data Sheet (SDS) ships with every order. SDS documents are available in English, Spanish, French and Japanese. A Technical Data Sheet (TDS) is also available for process reference. Lot-specific Certificates of Analysis (COA) can be requested at the time of order to verify the batch specifications for your receiving QC.
Why Buy from Alliance Chemical
This product is available across a full industrial range — 1-quart bottles through 330-gallon totes — so you can match the pack size to your actual consumption without overbuying. Alliance Chemical has operated as a hazmat chemical distributor since 1998, serving over 55,000 customers from our warehouse at 204 S Edmond St, Taylor, Texas 76574. Shipping and handling guidance for this product is reviewed by Andre Taki, DOT Hazmat Specialist.
