The abbreviation “DOA” comes up often in the chemical and plastics industries, but in purchasing and quality processes it matters to identify the product by its full identity, not just the abbreviation. In this article we have compiled the chemical name, CAS number, other names and basic properties of DOA (dioctyl adipate), used in PVC as a phthalate-free plasticizer. For a general introduction, see also our article What Is DOA Plasticizer?
Basic identity
- Common name: DOA, dioctyl adipate
- Chemical name: bis(2-ethylhexyl) adipate
- Other abbreviation: DEHA
- CAS number: 103-23-1
- Molecular formula: C22H42O4
What does adipate mean?
DOA is an ester of adipic acid, a linear six-carbon dicarboxylic acid. In DOA this acid is esterified with two 2-ethylhexyl alcohol groups. This structure, which contains no benzene ring, sets DOA apart from plasticizers in the phthalate and terephthalate classes. Because of its aliphatic structure, DOA is classified in the industry as a non-phthalate plasticizer.
Why does it have different names?
“Dioctyl” is a common name describing the eight-carbon side chains in the molecule; in systematic naming these chains are given as 2-ethylhexyl. DOA, DEHA and bis(2-ethylhexyl) adipate therefore refer to the same product. Different combinations of these names can appear in technical documents and commercial paperwork. The CAS number identifies the product with a single reference, regardless of naming.
Appearance
At room temperature DOA is a colourless or very light-coloured, oily, clear liquid. Because of this appearance it is also called “DOA oil” in the industry. Colour and other technical values are given in the technical data sheet and are confirmed per product.
Its role in PVC
DOA is a plasticizer that makes PVC flexible. Its most distinctive feature is that it helps PVC stay flexible at low temperatures, which is why it is often chosen for flexible PVC products used in cold environments. DOA is usually formulated not on its own but together with a general-purpose plasticizer such as DOTP, balancing general properties with cold flexibility.
DOA and DOTP
DOA and DOTP are the two phthalate-free plasticizers most often mentioned together. DOTP stands out in general-purpose use, while DOA is preferred in formulations where flexibility in the cold matters. We explain how the two are used together in our article DOA and DOTP Blends. For DOTP, see our DOTP plasticizer page.
Identifying the right product in documents
When identifying DOA in quotes and orders, it helps to use the following together:
- Common name and abbreviation (DOA)
- Chemical name (bis(2-ethylhexyl) adipate)
- CAS number (103-23-1)
- Required grade and technical values
- Packaging type
Confusion with similar names
The abbreviation “DOA” can mean other things in other contexts; in the chemical industry it usually means dioctyl adipate. Using the CAS number alongside the abbreviation when searching or preparing documents reduces the chance of ending up with the wrong product.
Avoiding mix-ups with similar abbreviations
Similar-looking abbreviations are common in the plasticizer market. DOA, DOP, DOTP and DINP can be confused because of their similar letters. The most practical way to avoid this is to state the chemical name and CAS number alongside the abbreviation in orders. For DOA that is dioctyl adipate and CAS 103-23-1.
Quality teams can compare this information with the package label at goods receipt, and archiving the technical documents with the order provides a reference for later purchases.
Frequently asked questions
Are DOA and DEHA the same product?
Yes. DEHA is the abbreviation of bis(2-ethylhexyl) adipate and refers to the same product as DOA.
What is the CAS number of DOA?
The CAS number of DOA is 103-23-1.
Does DOA contain phthalates?
No. DOA is an adipate and is classified in the industry among non-phthalate plasticizers.
Conclusion
DOA is a phthalate-free plasticizer known as dioctyl adipate, DEHA and bis(2-ethylhexyl) adipate, with CAS number 103-23-1, and valued for flexibility in the cold. See our DOA plasticizer page for details, and send your approximate quantity and application via the quote form.