Amines & Amides Available — Bulk Only

L-Cysteine Hydrochloride Monohydrate (L-Cysteine HCl Monohydrate)

CAS 7048-04-6 · Formula C3H10ClNO3S · MW 175.64 g/mol

A free-flowing monohydrate salt of L-cysteine for food, flavor, and personal-care manufacturing. It is used as a reducing agent and dough conditioner in baking, as a flavoring agent and nutritional supplement, and as a reducing/hair-conditioning ingredient in cosmetics.

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HS Code
2930.90
At a Glance
Material Family
Amines & Amides
Record Type
Pure compound
Primary Role
Crosslinking / Curing · pH Adjustment
Applications & Use Cases
  • Dough conditioner: Reducing agent and dough strengthener in baking.
  • Flavoring agent: Food flavor ingredient.
  • Nutritional supplement: Soluble amino-acid ingredient.
  • Cosmetic ingredient: Reducing and hair-conditioning agent.
Physical Properties
Vapor Pressure
0.000264
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2930 . 90
Chapter 29
Organic chemicals
Heading 29.30
Internationally harmonized (WCO HS)
Subheading 2930.90
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
7048-04-6
Molecular Formula
C3H10ClNO3S
Molecular Weight
175.64 g/mol
IUPAC Name
(2R)-2-amino-3-sulfanylpropanoic acid;hydrate;hydrochloride
PubChem CID
InChI Key
QIJRTFXNRTXDIP-JIZZDEOASA-N
Synonyms & Trade Names
L-Cysteine hydrochloride monohydrate L-Cysteine hydrochloride hydrate H-Cys-OH.HCl.H2O (R)-2-Amino-3-mercaptopropanoic acid hydrochloride hydrate (R)-2-Amino-3-mercaptopropanoic acid hydrochloride xhydrate Cysteine HCl L-Cysteine HCl hydrate L-Cysteine (hydrochloride hydrate) L-Cysteine monohydrate monochloride L-CYSTEINE, HYDROCHLORIDE, HYDRATE (1:1:1) Cysteine, hydrochloride, hydrate (1:1:1) (2R)-2-amino-3-sulfanylpropanoic acid;hydrate;hydrochloride L-cysteine monohydrochloride monohydrate Cysteine hydrochloride (USP)
Full Description

L-Cysteine Hydrochloride Monohydrate is the monohydrate hydrochloride salt of the sulfur-containing amino acid L-cysteine. It is used as a reducing agent and dough conditioner in baking, as a flavoring agent and nutritional supplement, and as a reducing/hair-conditioning ingredient in cosmetics.

Frequently Asked Questions

What is L-Cysteine HCl Monohydrate used for?

It is the monohydrate hydrochloride salt of the sulfur-containing amino acid L-cysteine. Industrially it functions as a reducing agent and dough conditioner/strengthener in baking, as a food flavoring ingredient, as a soluble amino-acid input for nutritional formulations, and as a reducing and hair-conditioning ingredient in cosmetics.

Is L-Cysteine HCl Monohydrate water soluble?

Yes. The hydrochloride monohydrate salt is the freely water-soluble form of L-cysteine, which makes it the preferred grade where rapid dissolution into aqueous or dough systems is required versus the free base.

What is the CAS number and molecular formula?

CAS 56-91-7. It is supplied to FCC (Food Chemicals Codex) specification with Kosher certification. Lot-specific Certificate of Analysis and SDS documentation are available on request.

What is the HS code for L-Cysteine HCl Monohydrate?

It classifies under HS 2930.90 — organo-sulfur compounds, other. Confirm the final import classification with your customs broker for the destination country.

What bulk packaging and order quantities are available?

This is distributed as an industrial/food-grade ingredient in bulk packaging suited to manufacturing use. Submit your target volume and FCC/Kosher documentation needs through a bulk RFQ for current pricing, lead time, and available pack sizes.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.