How to Source 4-Butylresorcinol: CAS, 95–99% Purity, COA & Storage

Quick Answer

A 4-Butylresorcinol offer can look convincing in one line: 99% cosmetic grade. That line is not enough to approve the material. Current supplier and marketplace pages show 4-Butylresorcinol advertised at 95%, 98% and 99%. Some pages use GC, others use HPLC, and some do not explain the analytical basis at all. More importantly, current marketplace search results include at least one listing titled as 4-Butylresorcinol while showing CAS 13331-20-9 instead of the identity used by authoritative chemical records.

For a buyer, the order of operations matters: identity first. Batch documentation second. Purity and analytical method third. Storage and packaging next. Price comparison last. A higher percentage does not rescue an unresolved identity problem.

Start with the Chemical Identity, Not the Purity Headline

PubChem identifies 4-Butylresorcinol, also called 4-n-Butylresorcinol, as CAS 18979-61-8, molecular formula C10H14O2 and molecular weight 166.22 g/mol.[1] The record also links this identity to CAS Common Chemistry, EPA DSSTox, ECHA and FDA GSRS. That gives procurement a stable anchor. When reviewing a supplier page, purchase specification or COA, the product name and CAS should agree with the identity you intend to qualify. This is especially important for substituted resorcinols because position matters.

A current Alibaba search result has displayed a product titled 4-Butylresorcinol 99% while also showing CAS 13331-20-9. Independent chemical indexing assigns CAS 13331-20-9 to 2-butylbenzene-1,3-diol, not 4-butylbenzene-1,3-diol. That does not prove why the marketplace field is wrong. It does create a hard-stop document conflict. Do not solve that conflict by assuming the title is right and the CAS is a typo. Ask the supplier to provide the current specification, SDS, batch COA and, when needed, identity evidence that all point to the same material.

Why 95%, 98% and 99% Are Not a Quality Ranking

Current commercial pages show a broad purity ladder. You can find 95% cosmetic-grade offers, 98% offers and 99% offers. It is tempting to place them in a simple order: 99% is best, 98% second, 95% lowest quality. That is not a defensible sourcing rule. The percentage tells you little until you know what field is being reported and how it was measured. Tokyo Chemical Industry's current 4-Butylresorcinol reference product B3773 lists purity above 98.0% by GC. Sigma's analytical standard lists an assay of at least 97.0% by GC. Commercial cosmetic pages may instead advertise 98% or 99% with HPLC wording.

Those products are not automatically contradictory. They may use different grade definitions, analytical methods, acceptance criteria and intended-use contexts. A 99% headline without a method or batch result is weaker procurement evidence than a lower numerical specification supported by a coherent identity test, method, chromatogram and lot-specific result.

GC and HPLC Percentages Are Not Self-Interpreting

Gas chromatography and high-performance liquid chromatography are different analytical techniques. The correct buyer question is not Which method is better? It is:

What exactly does this reported percentage mean in this supplier's specification?

For one supplier, the field may be chromatographic area purity. For another, it may be described as assay or content. The method may use a different detector, reference standard, sample preparation or calculation basis. That means a 98% GC result and a 99% HPLC result should not be compared as if the only difference were one percentage point.

Ask for:

• the field name on the specification
• the test method
• the acceptance criterion
• the actual batch result
• the reference standard or identification basis where relevant
• the chromatogram or method summary when the decision risk justifies it

If two suppliers cannot explain what their own purity number measures, the numbers should not drive the purchase decision.

Read the COA as a Batch Document

A COA should not be treated as decorative paperwork. The first task is document-to-product matching. Check that the COA identifies the same product name and CAS as the offer you are evaluating. Then confirm that the document is tied to a batch or lot.

After that, separate specification from result. A useful qualification review asks:

• What was the acceptance limit?
• What did this batch actually test at?
• Which method produced the result?
• Is the identity test separate from the purity test?
• Are the physical properties consistent with the grade?
• Are relevant impurity or residual fields addressed for this supplier's process?
• Is the document current for the shipment or only a generic example?

Do not invent a universal 4-Butylresorcinol COA from one supplier's template. One manufacturer may control a field that another supplier does not report. The correct requirement depends on your risk assessment, process knowledge and market obligations. The important point is that 99% should be one line in a larger qualification package, not the package itself.

Sample COA Is Not Shipment-Lot Evidence

Supplier websites often provide a downloadable sample COA. That can be useful during discovery. It can tell you what the supplier normally measures and whether the document structure is serious enough to continue the RFQ. It does not prove the incoming shipment has the same result. Before approval, request the COA for the actual offered or shipped lot. For higher-risk qualification, the buyer may also need independent incoming identification or purity confirmation according to the company's own quality system.

This is particularly important when public marketplace fields already show identity inconsistencies. A clean-looking sample PDF should not override a conflicting label, CAS or product page.

Storage Information Needs the Same Exact-Grade Discipline

Storage guidance is another place where buyers over-generalize. TCI's current reference-material page for 4-Butylresorcinol recommends cool, dark storage below 15°C, storage under inert gas and marks the material as air sensitive. That is valuable technical information. It is not a universal instruction that can be copied onto every commercial cosmetic-grade specification. A bulk supplier may use a different package size, headspace strategy, barrier material, retest period or validated storage condition.

Use the reference information to ask better questions:

• What storage temperature is specified for this exact grade?
• Is light protection required?
• How is the package sealed?
• Is inert headspace used or recommended?
• What is the retest or expiry period?
• What happens after the package is opened?
• Is partial-pack resealing addressed?
• Does the supplier have stability data supporting the stated storage condition?

The buyer's job is to connect storage requirements to the exact material and package being purchased.

Clinical Evidence Does Not Validate a Raw-Material Supplier

4-Butylresorcinol has meaningful topical human evidence, which is one reason the ingredient is commercially interesting. A randomized, double-blind, vehicle-controlled split-face study evaluated a 0.1% 4-n-butylresorcinol cream in 20 patients with melasma for eight weeks. The treated side showed a significant reduction in melanin index compared with vehicle.[2] A separate randomized, double-blind, split-face study evaluated a 0.1% liposome-encapsulated formulation in 23 patients and also reported improvement versus vehicle after eight weeks.[3]

A later multicenter study evaluated a 0.3% cream in 52 Indian subjects and reported improvement in mMASI over eight weeks, but that study was open-label and single-arm rather than vehicle-controlled.[4] Kolbe and colleagues also reported strong inhibition of human tyrosinase in biochemical work and clinical improvement of age spots in topical use.[5] These studies support the relevance of the molecule and finished formulations tested. They do not prove that a marketplace powder labeled 99% is equivalent to the material used in those studies.

Clinical evidence belongs to the ingredient and tested formulation context. Supplier qualification still requires identity, method, batch and handling evidence.

Do Not Turn 0.1% and 0.3% into a Raw-Material Grade Comparison

The human studies also illustrate another common sourcing error. A buyer may see successful 0.1% and 0.3% finished creams and conclude that a higher-purity raw material must deliver better clinical performance. That connection has not been demonstrated by these studies. The 0.1% trials and the 0.3% observational study differ in design, population and formulation. One 0.1% study specifically used liposome encapsulation. They are not a controlled comparison of 95% versus 98% versus 99% raw powder. If you need a dose or formulation decision, that deserves its own evidence review.

For sourcing, keep the question narrower:

Does this supplier offer the chemical identity and quality profile my formulation has been qualified around?

Use Current Marketplace Prices Only After the Technical Gate

Current public Alibaba results show how dangerous it is to lead with price. Recent search results have surfaced 4-Butylresorcinol offers around $205–215/kg, $299–380/kg, $330–400/kg, $500–550/kg and roughly $590–609/kg, along with lower-priced entries using different pack formats or conflicting identity fields. Those are public display prices, not verified transaction prices. They also do not share one purity method, one MOQ, one Incoterm or one document package. A $50–80 bag listing with a conflicting CAS is not directly comparable to a 1 kg offer anchored to CAS 18979-61-8.

Before price normalization, pass the technical gate. Only technically acceptable offers belong in the final commercial comparison.

Current Sourcing Status

Ingredexa currently has one verified 4-Butylresorcinol Alibaba sourcing candidate for this article.

A Practical Qualification Workflow

For a new 4-Butylresorcinol supplier, use this order.

1. Lock the identity

Confirm product name, CAS 18979-61-8, INCI / chemical naming consistency, SDS identity and specification identity. If the CAS conflicts with the intended chemical, stop.

2. Request the current specification

Do not rely on the marketplace title. The specification should state what the supplier actually releases against.

3. Review the lot-specific COA

Match the product, batch and actual results. Do not substitute a sample COA for shipment-lot evidence.

4. Understand the purity field

Identify whether the supplier reports assay, chromatographic purity, content or another metric. Record the method.

5. Review storage and packaging

Confirm the exact-grade storage condition, package type, retest or expiry period and opened-container handling.

6. Evaluate a sample before full commercial approval

Run your own formulation and incoming-quality checks as appropriate to the project. Do not infer formulation performance from the raw purity number alone.

7. Compare commercial offers only after qualification

Normalize MOQ, pack, freight, lead time, payment terms and current price only among offers that pass the technical gate. This order prevents procurement from optimizing the wrong material.

What Should Go on the RFQ?

A useful first RFQ for 4-Butylresorcinol should ask for:

• exact product name and CAS
• grade
• current specification
• current lot or representative batch COA
• assay or purity field and analytical method
• identity method
• SDS and TDS
• packaging configuration
• storage and retest / expiry
• MOQ and quantity tiers
• lead time
• origin / manufacturer status where relevant
• current quote and Incoterm

If the supplier claims 99%, ask how that number is defined. If the supplier claims cosmetic grade, ask what specification makes that grade different from its research or industrial material. If the page and documents disagree, resolve the disagreement before accepting the offer. Product identity, current specification, COA, MOQ, packaging, storage and commercial terms should still be reviewed before purchase because marketplace details can change.

Buyer Decision

The most important sourcing rule for 4-Butylresorcinol is simple: do not let purity become the first question. A 95%, 98% or 99% number is meaningful only after the chemical identity is correct, the method is understood, the COA matches the batch and the storage / packaging conditions are documented. For procurement, a clean identity chain beats a larger percentage printed in a marketplace title. That is the difference between shopping for a number and qualifying a raw material.

References

1. National Center for Biotechnology Information. PubChem Compound Summary for 4-Butylresorcinol, CID 205912.
2. Huh SY, Shin JW, Na JI, Huh CH, Youn SW, Park KC. The efficacy and safety of 4-n-butylresorcinol 0.1% cream for the treatment of melasma: a randomized controlled split-face trial. Annals of Dermatology. 2010;22(1):21–25. doi:10.5021/ad.2010.22.1.21.
3. Huh SY, Shin JW, Na JI, Huh CH, Youn SW, Park KC. Efficacy and safety of liposome-encapsulated 4-n-butylresorcinol 0.1% cream for the treatment of melasma: a randomized controlled split-face trial. Journal of Dermatology. 2010;37(4):311–315. doi:10.1111/j.1346-8138.2010.00787.x.
4. Khemis A, et al. Assessment of efficacy, safety, and tolerability of 4-n-butylresorcinol 0.3% cream: an Indian multicentric study on melasma. Clinical, Cosmetic and Investigational Dermatology. 2016;9:39–43. PMID: 26855596.
5. Kolbe L, Mann T, Gerwat W, et al. 4-n-butylresorcinol, a highly effective tyrosinase inhibitor for the topical treatment of hyperpigmentation. Journal of the European Academy of Dermatology and Venereology. 2013;27 Suppl 1:19–23. PMID: 23205541.