Plastic Additive CAS Number Lookup: Search 437 Substances by CAS, EC, Name or Trade Name

This CAS number lookup searches 437 plastic additives by CAS number, EC number, chemical name, abbreviation, synonym or trade name, and tests every CAS number you type against its check digit. One search box covers all six identifier types, so "DOP", "Palatinol AH", "117817" and "204-211-0" all lead to the same record: DEHP, CAS 117-81-7.

Results update as you type, exact matches are listed before partial ones, and a mistyped CAS number is flagged as malformed instead of silently returning nothing. When no record matches, the lookup says so and offers the closest names or the CAS numbers one typing error away.

What the Plastic Additive CAS Number Lookup Returns#

The lookup returns one result card per matching substance, with 8 fields: name, abbreviation, CAS number, EC number, formula, molecular weight, additive family and function. The 437 records span 31 of the 43 families of plastic additives, from plasticizers and antioxidants to flame retardants and colorants, and the date of the data is shown in the tool's header.

Each card also names the field the query matched, for example "Exact match on synonym: DOP", so a result found through a trade name is never mistaken for a result found through its CAS number. A "Full profile" link appears only when the substance's own page is published.

The 8 output fields and what each one holds are listed in the table below, with the DEHP record as the example.

What the search box accepts#

The search box accepts 6 identifier types, and the lookup decides which one you typed without a mode selector.

• CAS numbers with hyphens (117-81-7), without hyphens (117817) or with spaces (117 81 7)
• CAS numbers without the check digit (117-81), completed by computing the missing digit
• EC numbers in the 3-3-1 pattern (204-211-0), with or without hyphens
• Chemical names (bis(2-ethylhexyl) terephthalate)
• Abbreviations and synonyms (DOTP, DEHT, Antioxidant 1010)
• Trade names, with or without the supplier in brackets (Irganox 1010, Hexamoll DINCH)

A family name such as "plasticizer" or "flame retardants" lists that family's substances after any direct name matches.

How to Look Up a CAS Number in 5 Steps#

Look up a CAS number in 5 steps: type an identifier, read the check-digit line, check the match type, compare the identifiers and open the full profile.

1. Type a CAS number, EC number, chemical name, abbreviation, synonym or trade name into the search box.
2. Read the line above the results: a green line confirms a valid CAS number or a completed check digit, a red line flags a malformed number.
3. Check whether each result is an exact or a partial match, and on which field it matched.
4. Compare the CAS number, EC number, formula and molecular weight on the card with the safety data sheet, specification or certificate in hand.
5. Open the full profile, where one is published, for dosage, polymers and regulatory status.

Every search is also written into the page address, so a link such as /tools/cas-lookup/?q=117-81-7 reopens the same result.

How the CAS Check Digit Validation Works#

The last digit of a CAS number is a check digit: multiply the other digits by 1, 2, 3 and so on, starting from the right, add the products and keep the last digit of the sum. The lookup runs this calculation in the browser on every CAS-shaped entry, before it searches.

For DEHP, CAS 117-81-7, the 5 digits before the check digit are 1, 1, 7, 8 and 1. Read from the right, the products are 1 × 1, 8 × 2, 7 × 3, 1 × 4 and 1 × 5, which sum to 47, so the check digit is 7. The same rule gives 2 for DOTP, CAS 6422-86-2 (sum 92).

The lookup reads each entry shape in a fixed way, as the table below shows.

What a valid check digit proves#

A valid check digit proves that a CAS number is well formed, not that it belongs to the substance you mean. The weighting catches every swap of two different neighbouring digits in the first two parts and most single-digit typing errors, but a number can pass the check and still be the CAS number of a different chemical.

A malformed number is never matched to a record, because a corrected guess could point to the wrong substance. Instead, the lookup lists the CAS numbers in this reference that differ by one digit or by one swap of neighbouring digits: 117-18-7 fails the check (its check digit would be 0) and is one swap away from 117-81-7, DEHP.

Worked Example: DOP, DEHP and CAS 117-81-7#

Typing "DOP" returns one exact match: DEHP, bis(2-ethylhexyl) phthalate, CAS 117-81-7, EC 204-211-0, formula C24H38O4, molecular weight 390.6 g/mol, additive family Plasticizers. The card states "Exact match on synonym: DOP", because DOP is the trade usage for DEHP and not a separate substance. The full record is on DEHP (DOP, dioctyl phthalate), which the card links as its full profile.

The same record is reached 5 other ways: "DEHP" (abbreviation), "Palatinol AH" or "Vestinol AH" (trade names), "117817" (digits only) and "204-211-0" (EC number). The search "dioctyl phthalate" returns DEHP first as an exact synonym match and di-n-octyl phthalate (DNOP, CAS 117-84-0) second as a partial match, because DOP in trade usage means DEHP and must not be confused with DNOP.

The 4 records in the table below share one formula and one molecular weight, which is why a formula is never enough to identify a plasticizer and the CAS number is.

All values as recorded in the lookup data. DOTP is a terephthalate, not an ortho-phthalate, although it has the same formula as DEHP.

Data Source and Limits of the CAS Number Database#

The lookup draws on the same 437 records that make up the site's plastic additives database, and every identifier in it is compiled from the sources cited on each substance profile. The full plastic additives database lists those records with their CAS numbers, functions and dosage; this page only searches them.

Of the 437 records, 429 carry at least one CAS number, 43 carry more than one, and the lookup indexes 478 distinct CAS numbers in all. The data has 5 limits that every result should be read against.

1. Scope. The records cover additives used in plastics only. A chemical with a valid CAS number but no plastics additive use, such as a cement admixture or a food additive, has no record here.
2. Several CAS numbers per record. The CAS field shows every number as stored, primary first ("primary; also X"), and a search on any of them finds the record.
3. Shared CAS numbers. One CAS number can return 2 records: carbon black and electroconductive carbon black share 1333-86-4.
4. No single CAS number. 8 records, such as FUSABOND anhydride-modified polyolefins and Joncryl ADR epoxide oligomers, are polymers or commercial products recorded without one; search them by name.
5. EC numbers as written. EC numbers are matched exactly, and some records carry an ECHA list number in the EC field, marked as such in brackets.

A number the record rules out is not indexed: HBCD's CAS field notes "Not 3194-57-8 (that CAS is TBCO)", so 3194-57-8 does not return HBCD.

CAS Numbers, EC Numbers and Trade Names: Which Identifier to Use#

Use the CAS number to identify a substance, the EC number for European registration and the trade name only to find the first two. Trade names change with suppliers and grades, while the CAS number stays with the chemistry, which is why every result card leads with the identifiers.

CAS number vs EC number#

A CAS number and an EC number identify the same substance in two different registries. The two formats are compared in the table below.

Why one additive carries 2 CAS numbers#

One additive carries 2 CAS numbers when two registries or two commercial forms describe the same product. Chimassorb 944 is listed under 71878-19-8 in the EU and 70624-18-9 in the US (TSCA Inventory and 21 CFR 178.2010). DINCH is 166412-78-8, and the US product is listed under 474919-59-0. Commercial DIDP carries 68515-49-1 and 26761-40-0, and EU 10/2011 FCM 729 lists both.

The lookup finds each of these records from either number; the DINCH profile explains which CAS number applies where.

When to use the trade name lookup#

Use the trade name lookup when you need equivalent products from other suppliers, not just the CAS number. This page answers "what is the CAS number of Irganox 1010": 6683-19-8. Finding Songnox 1010, ADK STAB AO-60 and the other grades sold for the same chemistry is the job of the plastic additive trade name lookup.

Checking REACH, SVHC and regulatory status after a CAS lookup#

A CAS number is the key to every regulatory check, but this lookup does not show regulatory status. The obligations attached to a CAS number under Regulation (EC) No 1907/2006 are explained on REACH and plastic additives.

DEHP, for example, has been on the Candidate List since 28 October 2008, while DOTP and DINCH are not. Every plastic additive on that list is collected on the SVHC Candidate List page.

A status check across REACH, FDA food-contact rules and EU 10/2011 for one CAS number at a time is the job of the additive regulatory status checker.

Other plastic additive tools: calculators and supplier finder#

Three more tools work with the substances found here.

• The PHR to weight percent calculator converts a recipe between phr, wt%, ppm and kilograms per batch.
• The let-down ratio calculator turns a masterbatch dose into the additive level in the part.
• The plastic additive supplier finder sends one request with the CAS number to several suppliers.

Frequently asked questions#

What is a CAS number?#

A CAS Registry Number is the numeric identifier that Chemical Abstracts Service assigns to a chemical substance. It is written in 3 parts joined by hyphens, 2 to 7 digits, 2 digits and 1 check digit, for example 117-81-7 for DEHP.

How do I find the CAS number of a plastic additive?#

Type the additive's name, abbreviation or trade name into the lookup. DOP, Palatinol AH and dioctyl phthalate all return DEHP, CAS 117-81-7, EC 204-211-0.

Is a CAS number the same as an EC number?#

No: a CAS number is a worldwide registry identifier with 5 to 10 digits, and an EC number is the European identifier with 7 digits. DEHP is CAS 117-81-7 and EC 204-211-0.

Why does the lookup say my CAS number is invalid?#

The last digit of every CAS number is computed from the others, and yours does not match. The number contains a typing or transcription error, such as 117-81-2 instead of 117-81-7.

Can one CAS number return 2 results?#

Yes, when 2 records in this reference carry the same number. Carbon black and electroconductive carbon black share 1333-86-4, and Chimassorb 944 and its blend with Tinuvin 622 share 71878-19-8.

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