DL-Methionine (MET): A Deep Dive into Its Physical Characteristics and Chemical Profile

What is DL-Methionine?

DL-Methionine, commonly recognized as MET, is a synthetic essential amino acid produced through chemical synthesis from acrolein, methyl mercaptan, and hydrogen cyanide. The “DL” prefix signals the presence of both D- and L-isomers in its structure, setting it apart from the naturally occurring L-methionine in proteins. The significance of methionine lies in animal feed and pharmaceutical use, filling nutritional gaps where natural feedstuffs fall short. In the context of its widespread industrial production and global trade, the compound’s HS Code lands at 293040, guiding its movement across international borders and regulatory bodies.

Products, Forms and Specifications

Most DL-Methionine on the market presents itself as a solid, either in the form of white crystalline powder, small pearls, or irregular flakes. It can appear slightly yellow under certain light due to production variations, yet high-quality forms stay largely colorless and odorless. Powder and crystalline versions dissolve easily in water, which proves useful in preparing solutions for liquid feed applications and chemical processing. As a raw material, its purity often exceeds 98% on a dry basis, ensuring accurate dosage and predictable performance in specialized applications, whether in large-scale feed mills or pharmaceutical labs.

Molecular Structure and Properties

Chemical formula for DL-Methionine stands at C5H11NO2S, putting one sulfur atom right at the center of its thioether side chain. This structure brings unique chemical reactivity to the table. The molecular weight clocks in at roughly 149.21 g/mol. As a solid, DL-Methionine carries a melting point in the vicinity of 280°C, with decomposition, and it resists volatilization thanks to low vapor pressure. Its density hovers around 1.34 g/cm³, making it denser than many common organics but easy to store and handle. Water solubility reaches moderate levels—about 30g per liter at 20°C—supporting use in solution, including injectable pharmaceutical formulations and specialty feeds that demand precise dosing.

Safe Handling, Hazards, and Environmental Concerns

On the safety front, DL-Methionine remains low-risk for the majority of daily handlers. According to global chemical safety databases, the material doesn't register as highly hazardous; ingestion in the intended manner, such as livestock consumption within approved feeding rates, does not pose major health threats. Still, inhalation of dust can irritate respiratory passages, and repeated skin contact may lead to minor irritation. Its chemical stability leaves little risk for spontaneous hazardous reactions under normal temperature and humidity. The compound does not meet the criteria for classification as carcinogenic, mutagenic, or reproductive toxic by major regulatory authorities. In my work with industrial operators and lab technicians, proper use of dust masks, gloves, and eye protection remains standard procedure. Controls are in place to prevent dust formation or accidental release, protecting both users and the environment from mishandling. Spills should be collected quickly, avoiding sweeping or vacuuming methods that kick fine particles into the air. DL-Methionine is not classified as a marine pollutant yet, but significant releases into waterways can upset aquatic nitrogen cycles, another important reason to manage waste responsibly.

Availability in Market Forms and Raw Material Sourcing

Industries source DL-Methionine in a range of grades, with bulk raw material offered to feed, food, pharmaceutical, and chemical sectors. The choice between powder, flakes, or pearls often boils down to storage and mixing requirements. Liquid concentrates have gained ground, allowing precise pump dosing and blending, yet solid forms remain dominant for storage life and cost. From my own purchasing experience in feed production, suppliers rarely deviate from specification sheets—they deliver strict controls on moisture, particle size, and bulk density to fit automated handling setups common in modern factories. Raw material inputs for synthesis include acrolein, which itself calls for careful stewardship and safety protocols during production and transport. These upstream chemicals raise concerns around workplace safety, sustainable sourcing, and minimization of hazardous process byproducts.

Solutions and Innovations in DL-Methionine Handling

Efficient storage and handling methods make a real difference for both economic value and safety. Advancements such as fully enclosed silos, automated vacuum transfer, and dust-collection systems keep worker exposure minimal and product loss low. Training operators to monitor humidity guards against caking and breakdown of physical form. On the sustainability front, the industry keeps exploring greener synthesis pathways, striving for process chemistry that reduces solvent waste and optimizes recovery of side-streams. Regulations around labeling and shipping—requiring clear marking with the HS Code and chemical name—ensure down-the-line users, shippers, and regulatory officials can trace and check product identity without confusion. These measures support safer, more responsible growing chains and limit potential health and environmental risks associated with mishandling.

The Future of DL-Methionine Use and Safety

DL-Methionine’s continued role in feed and nutrition circles can’t be underestimated. Population growth, demand for animal protein, and ongoing research into animal health push need for ever more precise amino acid nutrition. Close attention to specification, batch-to-batch consistency, and compliance with international chemical safety codes remains as relevant as ever. Problems still pop up when storage conditions fall short, or when handlers overlook dust or spill cleanup, so regular training and improvements in bulk logistics fit into a broader culture of safety. Long-term, success depends on tight control—from the molecular formula to the final product delivered to end users—anchored in science, clear regulation, and real-world experience with the risks and possibilities of this critical raw material.