2-[Bis(2-Hydroxyethyl)Amino]ethanesulphonic acid, often known by its shorthand BES, plays a recognizable role in labs and a wide range of industries. This compound usually serves as a buffering agent. Its molecular formula is C6H15NO4S. The structure shows a sulfonic acid moiety tethered to an amino group, with two 2-hydroxyethyl chains. Each part of the molecule matters for its reactivity and solubility. Chemists often turn to BES because of these functional groups. HS Code classification for BES falls under 2922 (Oxygen-function amino-compounds), which covers a large spectrum of amino-related chemicals and their derivatives.
BES often comes as a white crystalline solid. It dissolves well in water, which makes it easy to prepare as a solution. Its density sits around 1.4 g/cm³, varying slightly based on manufacturer and storage conditions. Several forms exist: powder, flakes, crystalline granules, and pearls all show up in orders, depending on need. This flexibility means fewer headaches with preparation and measurement. BES resists changes in pH near its pKa of 7.15 at room temperature, which supports reliable use as a buffer system around physiological conditions. The solubility in water allows straightforward handling compared to less soluble sulfonic acids. Moisture can cake BES, so users keep containers sealed and stored in cool, dry areas.
Understanding BES starts with structure. The molecule features a central sulfur atom double-bonded to two oxygen atoms, attached to a two-carbon chain ending at a nitrogen. This nitrogen holds two hydroxyethyl chains. Such a structure allows strong hydrogen bonding with water or compatible solvents. BES particles often show up under the microscope as small, sharply edged crystals or amorphous clumps, depending on drying techniques. Purity levels typically hit above 99%, which suits the demands of analytical and synthetic work. Some suppliers offer the material as a pre-mixed solution or sell by the kilogram as a dry solid. Details like melting point (about 275°C, decomposing before actual melting) help those who must process it at higher temperatures or need stability within thermal reactions.
Every shipment brings attention to form and quality. BES can come as solid powder or as free-flowing flakes, shaped to allow easy dispersion in liquids. Some facilities choose pearls for automated feeding systems, while labs choose powder for quick weighing and solution-making. Densities vary by form: compacted pearls usually run denser than loose crystalline powder. Experience in laboratories teaches that the right storage container prevents moisture absorption and caking. Crystals dissolve with little effort in cool or warm water, making preparation straightforward. Frequent reactivity questions relate to stability under light and air; BES sustains its quality under typical storage, given low humidity and absence of aggressive oxidizers. Lab accidents rarely link directly to BES, yet general chemical hygiene always applies.
BES has a solid safety profile, generally considered non-toxic under common working conditions. Extended skin contact or ingestion, though, produces discomfort or mild irritation. Chemical suppliers mandate gloves and goggles for handling, not because danger looms, but because unpredictability always finds a way in the chemistry lab. Data indicate BES is not classified as a carcinogen or significant environmental pollutant, but safe disposal remains essential. Spilled BES crystals feel slippery beneath the shoe—a hazard easily overlooked. That calls for vigilant cleaning and labeling in busy workspaces. Chemical waste disposal procedures keep BES solutions from sewer systems, since even low-hazard chemicals upset water treatment balances when dumped en masse.
Careful attention to the molecular structure of BES helps scientists and manufacturers predict compatibility in formulations. Its sulfonic acid group and hydroxyethyl branches allow widespread use—buffering, electrophoresis, biochemical experiments, and some medical applications. The balance between acidity and base acceptance allows for tight pH control near neutrality. This is indispensable in enzyme-driven or cell-based experiments. Even small batches from raw materials need careful quality control. Accurate molecular weights, clear Certificates of Analysis, and third-party validations of purity limit headaches for those on the research frontier or managing regulated production.
Industries lean heavily on BES as a raw material because it plays a supporting role in larger processes: medical labs hit the buffer shelf for BES almost as often as for Tris or HEPES. Biotech companies, water treatment plants, and diagnostic reagent makers keep it stocked to ensure product stability and regulatory compliance. The chemical rarely causes synthesis byproducts that complicate downstream work—a detail that keeps production costs in line. Demand for BES continues to rise as precision medicine and advanced diagnostics become the norm. Work directly with chemical suppliers, confirm proper safety data, and establish rigorous purchasing practices: these steps protect both worker health and bottom line.
BES demands respect in storage practice. Keep it in original, labeled containers, away from acids, oxidizers, or food prep areas. Even though its risk factors sit on the mild side, confusion with similar looking chemicals happens. MSDS sheets and clear signage make a difference. Most experiences show that a few basic steps—routine inspection of storage environments, disciplined waste handling, and communication across staff—go further than elaborate warning systems. Take note: material checks on incoming shipments prevent expensive mix ups. As more industries adopt BES for specialty applications, responsible handling grows even more important. Chemical education, hands-on experience, and consistent protocols shape how BES fits into the daily grind of science and production.
