Diethanolamine (DEA, CAS 111-42-2) is a secondary alkanolamine that plays a modest but important role in pharmaceutical formulation. It is rarely the active ingredient; instead, it is used as a processing and performance aid that helps other ingredients behave correctly. Understanding what DEA does, which grades are available and how quality is controlled helps formulators and buyers make informed decisions.
Diethanolamine at a Glance
| Property | Value |
| Chemical name | 2,2'-Iminodiethanol (diethanolamine) |
| CAS number | 111-42-2 |
| Molecular formula | C4H11NO2 |
| Molecular weight | 105.14 g/mol |
| Appearance | Colorless to pale yellow liquid or crystalline solid |
| Boiling point | Approx. 268.8 °C |
| Flash point | Approx. 138 °C (closed cup) |
| Density | Approx. 1.097 g/cm3 at 20 °C |
| Solubility | Miscible with water; soluble in alcohols and acetone |
Key Pharmaceutical Functions
pH adjustment and neutralization: DEA neutralizes acidic actives and excipients, helping formulations reach a target pH that supports stability and bioavailability.
Emulsification: In creams, lotions and ointments, DEA can act as an emulsifying aid, improving the uniformity and stability of oil-in-water systems.
Salt and complex formation: It can form salts or complexes with certain acidic drugs, modifying solubility or stability to aid formulation.
Buffering: In combination with appropriate acids, DEA contributes to buffering systems that keep pH within a defined range during storage.
Grades and Quality Control
DEA is supplied in industrial, cosmetic and pharmaceutical-relevant grades. For pharma-adjacent applications, buyers should request specification sheets covering assay (typically 99% or higher), water content, color (APHA), and limits for related amines such as monoethanolamine and triethanolamine. Because secondary amines can form nitrosamines under certain conditions, responsible manufacturers and distributors control precursors and document impurity profiles. Batch-specific certificates of analysis (COA) should accompany every delivery.
Regulatory and Safety Considerations
DEA is classified under GHS with hazard statements including H302 (harmful if swallowed), H315 (skin irritation), H318 (serious eye damage) and H335 (respiratory irritation). It is also covered by chemical inventory and use regulations in major markets, so buyers must verify that the grade, end use and quantities comply with applicable rules. Handle DEA with gloves and eye protection, and store it in sealed containers because it is hygroscopic and can absorb carbon dioxide from air over time.
Sourcing and Supply Considerations
For bulk pharmaceutical-adjacent use, look for suppliers with ISO 9001 quality systems, consistent assay and impurity data, secure packaging (drums or IBC totes) and documented export compliance. Confirm the water content and color on arrival and check that the COA matches the batch number on the container. Reliable logistics partners keep transit time short because prolonged exposure to moisture can degrade quality.
Production and Industrial Use
Industrial chemicals such as solvents, acids, glycols and monomers are produced in continuous process plants from petroleum, natural gas or biomass feedstocks, using distillation, reaction and purification steps to reach the required purity grade. The product purity, typically expressed as a percentage such as 99.5 or 99.9 percent, is controlled by the reaction conditions and the final distillation, and the specification of each grade is defined in the product standard or the supply agreement. Because the same chemical is used across industries, from paints and adhesives to pharmaceuticals and polymer production, the grade and the impurity profile must be confirmed against the intended application.
Quality Control, Sampling and Documentation
The quality of a chemical delivery is confirmed by laboratory analysis of a representative sample taken at filling. In our inspection practice we verify the certificate of analysis against the ordered specification, check the appearance, color and water content of the product, and confirm the packaging, the lot number and the filling date on the drums or containers. For bulk deliveries, the sample is drawn from the tank according to a sampling procedure and analyzed for the key properties, and the retained sample is kept so that any dispute can be resolved from records. Safety documentation, including the hazard information for transport and handling, is part of every delivery.
Handling, Storage and Safety
Industrial chemicals are handled according to their hazard class, with the correct protective equipment and ventilation. Solvents are flammable and stored away from ignition sources, acids are stored in compatible containers with containment, and hygroscopic products are kept in sealed packaging. In our experience, the most common delivery problems are contamination from reused containers, water ingress in bulk loads and mixing of different grades, so each delivery is checked against the lot documentation before it is accepted into storage.
Quality Control and Documentation
Every delivery of industrial chemical should be supported by proper documentation that traces the material back to its production batch. In our inspection practice we verify the certificate against the order first, then check the critical dimensions, the surface condition and the marking on the goods themselves. The acceptance record is kept for each delivery, and third-party inspection can be arranged for projects that require independent verification. These documented checks are the difference between a delivery that runs smoothly through production and one that stops the line with a specification mismatch.
Selection Guidance
The correct industrial chemical specification is selected by the service environment, the forming or fabrication operation and the required service life. Over-specification increases cost without benefit, while under-specification leads to premature failure, so the acceptance values should be fixed at ordering and confirmed on the certificate at delivery. In our experience, specifications that state the governing standard, the required property values and the acceptance tests are the ones that cause the fewest disputes, because every party knows exactly what will be verified.
Inspection Checklist
A practical incoming inspection for industrial chemical covers the certificate check, the dimensional verification, the surface examination and the marking check. The certificate values are compared with the ordered limits, the dimensions are measured at the positions defined by the standard, and the surface is examined for the defects that matter for the intended application. Any deviation is recorded and agreed with the supplier before the material is released to production. This checklist takes minutes to run and prevents most downstream problems.
Common Misconceptions
Several misconceptions about industrial chemical appear regularly in procurement discussions. The first is that a higher grade always means better value, when the correct grade is the one matched to the actual service. The second is that the certificate alone guarantees the quality, when the physical verification is equally important. The third is that storage and handling do not matter, when surface damage and corrosion at the storage stage are among the most common causes of rejected deliveries. Understanding these points helps buyers avoid both waste and failure.
Quality Control and Documentation
Every delivery of industrial chemical should be supported by proper documentation that traces the material back to its production batch. In our inspection practice we verify the certificate against the order first, then check the critical dimensions, the surface condition and the marking on the goods themselves. The acceptance record is kept for each delivery, and third-party inspection can be arranged for projects that require independent verification. These documented checks are the difference between a delivery that runs smoothly through production and one that stops the line with a specification mismatch.
Selection Guidance
The correct industrial chemical specification is selected by the service environment, the forming or fabrication operation and the required service life. Over-specification increases cost without benefit, while under-specification leads to premature failure, so the acceptance values should be fixed at ordering and confirmed on the certificate at delivery. In our experience, specifications that state the governing standard, the required property values and the acceptance tests are the ones that cause the fewest disputes, because every party knows exactly what will be verified.
Inspection Checklist
A practical incoming inspection for industrial chemical covers the certificate check, the dimensional verification, the surface examination and the marking check. The certificate values are compared with the ordered limits, the dimensions are measured at the positions defined by the standard, and the surface is examined for the defects that matter for the intended application. Any deviation is recorded and agreed with the supplier before the material is released to production. This checklist takes minutes to run and prevents most downstream problems.
Frequently Asked Questions
Q: What is DEA used for in medicines?
A: DEA is mainly a formulation aid: it adjusts pH, helps emulsify creams and ointments, and can form salts with acidic drugs to improve solubility and stability. It is not typically the active pharmaceutical ingredient.
Q: What is the difference between MEA, DEA and TEA?
A: Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) are ethanolamines with one, two and three hydroxyl groups respectively. They differ in basicity, hygroscopicity and typical uses; DEA sits between MEA and TEA in molecular weight and reactivity.
Q: Is DEA safe in pharmaceutical products?
A: When used at approved levels in approved product types and manufactured to appropriate quality standards, DEA is accepted in regulated formulations. Any specific product must still satisfy the requirements of the relevant regulatory authority for that market.
Q: How is DEA quality verified?
A: Through specification testing - assay, water content, color, related amines, and impurity limits - documented in a batch certificate of analysis issued against an agreed specification.
Q: How should DEA be stored?
A: Store in tightly sealed containers in a cool, dry place, protected from moisture and carbon dioxide. Avoid contact with strong acids and oxidizers.
Q: Can DEA be used in injectable products?
A: Suitability for any specific dosage form depends on the formulation, the regulatory framework and the manufacturer's approval.