Acidulant formulations
Lactic acid is used in food and formulation processing. [3]
01
THE ESSENTIALS
Lactic Acid in 30 Seconds
One –COOH group provides carboxylic acidity. A separate –OH is attached to the next carbon, giving lactic acid an additional reaction site.
Lactic acid has one carboxyl group and a neighboring hydroxyl on a three-carbon chain. Its chiral center and common aqueous product forms make concentration and stereochemistry central to purchasing. [1] [3]
Safety at a glance — The listed concentrated Sigma lactic-acid solution 252476 (US listing) is classified as corrosive to skin and seriously damaging to eyes (H314). Concentrated commercial solutions can cause severe skin burns and eye damage; concentration and the exact product classification matter. Food or formulation uses do not make the concentrated raw material harmless. [4]
Condensed connectivity schematic; see the specified stereochemical identity below. [1]
02
GO A LITTLE DEEPER
Understanding Lactic Acid
THE SIMPLE EXPLANATION
The functional groups
One –COOH group provides carboxylic acidity. A separate –OH is attached to the next carbon, giving lactic acid an additional reaction site. [1]
A LITTLE DEEPER
What the structure changes
The hydroxyl-bearing carbon is chiral: L and D forms must be distinguished. An assay around 85–90% describes the listed product specification, not the percentage of one enantiomer. Some liquid products are packaged by mass, others by volume. [1] [4] [5] [6]
Technical detail Identity, dissociation & specification
This page’s general identity uses CAS 50-21-5. The L products in the table use CAS 79-33-4. Sigma lists a DL aqueous solution; TCI and Wako list L products. Their stereochemical and concentration specifications prevent an equivalent-price comparison. An assay expressed as lactic acid is not necessarily the mass fraction of free lactic-acid monomer. Concentrated commercial acid can contain intermolecular esterification/oligomeric species. Confirm total-acid basis, free-monomer basis, oligomer content and water content separately when relevant; the unassayed balance must not be assumed to be water. [1] [2] [4] [5] [6]
Acid–base reference values describe equilibria under specified conditions. They are not a substitute for a validated formulation or an assay on the purchased lot.
03
MAKE THE CONNECTION
How Lactic Acid Compares
Similar names and functional groups do not mean interchangeable chemicals.
SIDE-BY-SIDE COMPARISON
Lactic Acid vs Citric Acid
Hydroxymonocarboxylic acid
versusHydroxytricarboxylic acid
Fixed comparison for this prototype. Acid selectors are disabled; additional comparisons are coming later.
| Property | Lactic Acid | Citric Acid |
|---|---|---|
| Molecular formula | C₃H₆O₃ [1] | C₆H₈O₇ [7] |
| Molecular weight | 90.08 g/mol [1] | 192.12 g/mol [7] |
| Carbon atoms | 3 [1] | 6 [7] |
| Carboxyl groups | 1 [1] | 3 [7] |
| Structure | CH₃–CH(OH)–COOH [1] | HOOC–CH₂–C(OH)(COOH)–CH₂–COOH [7] |
| Chemical family | Hydroxymonocarboxylic acid [1] | Hydroxytricarboxylic acid [7] |
| Identity focus | Commercial liquids / aqueous solutions [1] | Solid · anhydrous identity [7] |
| pKa context | 3.86 (20 °C, in water) [2] | 3.128 / 4.761 / 6.396 (25 °C, water, zero ionic strength) [11] |
Chemical identities are compared here; supplier grades, concentrations, and stereochemical specifications are separate purchasing attributes. pKa values retain their stated conditions; no quantitative solubility ranking is implied. The structure schematic does not encode stereochemistry.
When Might You Choose One Instead of the Other?
Use the prescribed lactic stereoisomer and concentration for a synthesis or polymer route. Use the required citrate form for a citrate formulation. Compare specification, water content, and enantiomeric requirements before package price. [1] [3] [7]
Specified starting material
Lactic Acid
Match CH₃–CH(OH)–COOH and the method’s required chemical form.
Citric Acid
Match HOOC–CH₂–C(OH)(COOH)–CH₂–COOH; verify the identity before substituting a related acid.
Before choosing: match the reaction or formulation, then verify the exact form, grade, assay basis, and impurities. These contexts do not establish suitability for an industrial or regulated application.
04
FROM STRUCTURE TO APPLICATION
What Is Lactic Acid Used For?
Acidulant formulations
Lactic acid is used in food and formulation processing. Suitability depends on the required application specification, not just the assay percentage. [3]
Polymer feedstock
Lactic-acid chemistry contributes to polylactic-acid production. Stereochemistry and water content matter for the intended polymer process. [3]
Industrial processing
Used in textile and leather processing. Specify the concentration and impurities required by the process. [3]
06
SOURCE WITH CONTEXT
Lactic Acid Suppliers
Compare specific products and package options. Listings are not ranked recommendations.
3 suppliers · 3 products · 5 package listingsLatest supplier check: October 3, 2026
Package sizes stay grouped under the supplier product. Assay methods, product forms, and regional markets remain visible. Specify concentration, chemical assay and method, L/D/DL form, optical specification, water content, and package mass or volume separately.
Scroll horizontally if needed. Supplier and package identity stay visible.
| Supplier | Product / Grade | Purity / Assay | Package Size | Public Price | Normalized Price | Documentation | Last Checked | Action |
|---|---|---|---|---|---|---|---|---|
| Sigma-AldrichLactic Acid | ACS reagent · DL solution252476-500GCAS 50-21-5; assay method not stated in listing. Supplier discloses intermolecular esterification products; assay is not a verified free-monomer or water fraction. | 85.0–90.0% in H₂O | 500 g | $93.00USD · US public price | Not comparedGrades, assay bases, or forms differ | COA lookup on product page (opens new tab)SDSCheck supplierCOO lookup on product page (opens new tab) Document notes: Sigma-Aldrich
| View Product: Sigma-Aldrich, 252476-500G (opens new tab) | |
| ACS reagent · DL solution252476-1KGCAS 50-21-5; assay method not stated in listing. Supplier discloses intermolecular esterification products; assay is not a verified free-monomer or water fraction. | 85.0–90.0% in H₂O | 1 kg | $158.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: Sigma-Aldrich, 252476-1KG (opens new tab) | |||
| TCILactic Acid | Check supplierL0165L-lactic acid · CAS 79-33-4 · liquid sold by mass; confirm water content and assay basis. | >85.0% (neutralization back titration) | 25 g | $32.00USD · US public price | Not comparedGrades, assay bases, or forms differ | Document notes: TCI
| View Product: TCI, L0165 (opens new tab) | |
| Check supplierL0165L-lactic acid · CAS 79-33-4 · liquid sold by mass; confirm water content and assay basis. | >85.0% (neutralization back titration) | 500 g | $62.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: TCI, L0165 (opens new tab) | |||
| FUJIFILM WakoLactic Acid | Wako Special Grade · L form129-02666CAS 79-33-4; assay is not an optical-purity measurement. | 85.0–92.0% (titration) | 500 mL | $38.00USD · US list price | Not comparedGrades, assay bases, or forms differ | Document notes: FUJIFILM Wako
| View Product: FUJIFILM Wako, 129-02666 (opens new tab) |
Sigma-Aldrich
Lactic Acid
ACS reagent · DL solution
CAS 50-21-5; assay method not stated in listing. Supplier discloses intermolecular esterification products; assay is not a verified free-monomer or water fraction.
500 g
252476-500G- Public price
- $93.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
1 kg
252476-1KG- Public price
- $158.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
COA lookup on product page (opens new tab)SDSCheck supplierCOO lookup on product page (opens new tab)
Document notes: Sigma-Aldrich
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- A product-specific Certificate of Origin retrieval option was visible; no origin certificate was reviewed. Country of origin is unverified and is not inferred.
Last checked:
TCI
Lactic Acid
Check supplier
L-lactic acid · CAS 79-33-4 · liquid sold by mass; confirm water content and assay basis.
25 g
L0165- Public price
- $32.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
500 g
L0165- Public price
- $62.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: TCI
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
FUJIFILM Wako
Lactic Acid
Wako Special Grade · L form
CAS 79-33-4; assay is not an optical-purity measurement.
500 mL
129-02666- Public price
- $38.00USD · US list price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: FUJIFILM Wako
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Documentation evidence
COA = Certificate of Analysis · SDS = Safety Data Sheet · COO = Certificate of Origin.
Lookup means a retrieval option was visible, not that a lot certificate was reviewed. Check supplier means availability or the applicable document was not verified.
Prices may vary by quantity, account, contract, geography, and availability. These products have different grades, assay bases, or forms; no normalized comparison is shown. Foreign-market prices are reference listings only. No currency conversion, mass-to-volume conversion, or ranking is applied. Confirm equivalent specifications and a current quote before comparison. [4] [5] [6]
Verification limits & placement policy
Chemical assay, free-monomer content, water content and optical specification are different measurements. Confirm the assay basis and lot documentation; do not infer water content from the stated acid assay.
Only the displayed identity, specification, packages, public prices and stated documentation evidence were reviewed. Current stock, lead times, shipping eligibility, contract pricing, lot certificates, and regulatory suitability are unverified.
There are no paid placements. Future paid listings will show “Sponsored” in both views; payment will not determine chemistry interpretation or imply a ranking.
07
PLAN A LARGER ORDER
Need Lactic Acid in Bulk?
Turn your requirements into a clear supplier brief.
Bulk RFQ feature — coming soon. Prototype form: submissions are not currently sent to suppliers. Use sample details to prepare an on-screen brief.
Prepare a bulk request Prototype form
08
A BUYER’S CHECKLIST
Before You Buy Lactic Acid
Selections remain only while this page is open.
09
FOR YOUR REFERENCE
Lactic Acid Technical Reference
Identity, product reference properties, and handling context.
Identification Names, formula & identifiers
- Principal CAS
- 50-21-5
- Identity focus
- Commercial liquids / aqueous solutions
- Formula
- C₃H₆O₃
- Molecular weight
- 90.08 g/mol
- IUPAC name
- 2-hydroxypropanoic acid
- Connectivity SMILES
- CC(C(=O)O)O
- PubChem CID
- 612
Connectivity SMILES describes connectivity; it is not an independent stereochemical assignment. CAS and product-form distinctions are supported by the supplier listings. [1] [4] [5] [6]
Physical Properties Product references & conditions
The displayed products are concentrated solutions. Thermal behavior depends on stereochemical and solution composition: neat racemic and enantiopure lactic acid differ materially, and their melting or boiling constants must not be assigned to these aqueous products. Sigma’s DL solution lists density 1.209 g/mL at 25 °C; Wako’s L product describes about 1.2 g/mL at 20 °C. These product-specific values do not support package or price conversions. [13] [4] [6]
Hydrate, concentration, stereoisomer, and temperature can change the relevant specification. Product reference data are not a reviewed lot certificate.
Acid/Base Properties Verified values & missing data
Reference pKa: 3.86 (20 °C, in water). [2]
Chemical assay, free-monomer content, water content and optical specification are different measurements. Confirm the assay basis and lot documentation; do not infer water content from the stated acid assay.
Temperature, ionic strength, and the use of activities versus concentrations matter in quantitative work. These reference values are not buffer recipes.
Safety at a Glance Product-specific hazards
The listed concentrated Sigma lactic-acid solution 252476 (US listing) is classified as corrosive to skin and seriously damaging to eyes (H314). Concentrated commercial solutions can cause severe skin burns and eye damage; concentration and the exact product classification matter. Food or formulation uses do not make the concentrated raw material harmless. [4]
Hazard classifications can vary by concentration, formulation, supplier and jurisdiction. Review the SDS for the exact product before handling. This summary does not replace the SDS.
Supplier safety information and SDS retrieval (opens new tab)
A product-page safety classification is not verification of every regional SDS. Confirm product code, chemical form and current local document.
Review supplier documentation10
COMMON QUESTIONS
Lactic Acid FAQ
What distinguishes Lactic Acid?
One –COOH group provides carboxylic acidity. A separate –OH is attached to the next carbon, giving lactic acid an additional reaction site. [1]
How does it differ from Citric Acid?
Citric acid has three carboxyl groups, while lactic acid has one and a stereocenter. A shared acidulant application does not make their pH response or polymer chemistry interchangeable. [7]
What must a buyer specify?
Specify concentration, chemical assay and method, L/D/DL form, optical specification, water content, and package mass or volume separately. [4]
Are the listed products directly price-comparable?
No. The table retains differing grades, assay bases, forms, and markets. No normalized ranking or currency conversion is applied. [5]
What reference data still need checking?
Chemical assay, free-monomer content, water content and optical specification are different measurements. Confirm the assay basis and lot documentation; do not infer water content from the stated acid assay.
Can I request a bulk quote here?
The RFQ is a prototype that prepares an on-screen brief. Nothing is sent to suppliers. Confirm actual bulk terms directly with the supplier.
11
TRACE THE INFORMATION
Sources & Editorial Notes
Identity and compiled reference values are separated from supplier-specific specifications. Structural comparisons and buyer guidance are editorial interpretation. Sources were checked October 3, 2026; supplier information can change.
- PubChem · chemical identity (opens new tab)
Official PUG REST identity record: formula, molecular weight, IUPAC name, and connectivity SMILES.
- PubChem · Lactic Acid dissociation references (opens new tab)
Lactic Acid compiled dissociation values; stated temperature and medium are retained. Unspecified conditions are not inferred.
- PubChem · applications (opens new tab)
Compiled application references; uses of derivatives are distinguished from direct use of the acid.
- Sigma-Aldrich · commercial product (opens new tab)
Direct product listing checked October 3, 2026. Product-specific grade, assay, package, public price and documentation retrieval evidence. Product-page safety information applies to the identified product and regional listing, not every grade or jurisdiction.
- TCI · commercial product (opens new tab)
Direct product listing checked October 3, 2026. Product-specific grade, assay, package, public price and documentation retrieval evidence. Product-page safety information applies to the identified product and regional listing, not every grade or jurisdiction.
- FUJIFILM Wako · commercial product (opens new tab)
Direct product listing checked October 3, 2026. Product-specific grade, assay, package, public price and documentation retrieval evidence. Product-page safety information applies to the identified product and regional listing, not every grade or jurisdiction.
- Citric Acid · identity (opens new tab)
Primary comparison identity. Explanations of structural differences are editorial interpretation of verified identities.
- Malic Acid · identity (opens new tab)
Related chemical identity; relevance is based on structure or the stated application relationship.
- Mandelic Acid · identity (opens new tab)
Related chemical identity; relevance is based on structure or the stated application relationship.
- Acetic Acid · identity (opens new tab)
Related chemical identity; relevance is based on structure or the stated application relationship.
- NIST · Citric acid aqueous ionization (opens new tab)
Goldberg, Kishore and Lennen (2002), table 7.22: evaluated aqueous pKa at 25 °C and zero ionic strength.
- OpenStax · Citric acid cycle (opens new tab)
Succinate and fumarate in the citric acid cycle; salts/ions are distinguished from purchased free acids.
- PubChem · lactic acid physical properties (opens new tab)
Compiled neat-acid and solution properties must be distinguished by stereochemistry and composition.
Review limits
Chemical assay, free-monomer content, water content and optical specification are different measurements. Confirm the assay basis and lot documentation; do not infer water content from the stated acid assay.
This informational prototype is not a supplier, quotation service, or endorsement of a product’s fitness for an application. Buyers should verify the applicable specification, certification, and regulatory requirements for their intended use.