Description

Technical Specifications

Parameter	Specification
Product Name	Chitosan Oligosaccharide Hydrochloride (COS-AG)
Common Name	Chitosan Oligosaccharide, COS, COSH
CAS Number	148411-57-8
Molecular Weight	< 3,000 Da (monomer unit)
Degree of Polymerization (DP)	2 – 20 (oligomeric chains)
Degree of Deacetylation (DDA)	≥ 95.0%
Zeta Potential	+70 mV (approx.) — high positive surface charge
pH (1% aqueous solution)	5.0 – 6.5
Appearance	Off-white to pale yellow free-flowing powder
Solubility	100% water-soluble — no acid required
Moisture Content	≤ 10.0%
Ash Content	≤ 1.5%
Insoluble Substance	≤ 1.5%
Grade	Agricultural (COS-AG)
Available Sources	Mushroom (Vegetal) | Insect (BSF)
COA Available	Yes — batch-specific, on request
MSDS Available	Yes — on request
Storage	Cool, dry, well-ventilated; avoid light, heat, and humidity
Shelf Life	24 months when properly stored
Organic Certification	EU 2021/1165 compliant — suitable for organic farming

 

How Chitosan Oligosaccharide Works: The Science of Plant Immunity

Understanding how COS-AG activates plant defence is critical for formulators and agronomists. The mechanism is well-documented in peer-reviewed research and distinguishes COS from conventional fertilisers or synthetic crop protection agents.

COS as a MAMP — Microbe-Associated Molecular Pattern

COS is recognised by plants as a Microbe-Associated Molecular Pattern (MAMP). When applied, COS binds to pattern recognition receptors (PRRs) on plant cell surfaces, triggering a signalling cascade that primes the plant’s immune system. This process is known as Pattern-Triggered Immunity (PTI) and leads to rapid, broad-spectrum defence activation without requiring actual pathogen presence.

Salicylic Acid (SAR) and Jasmonic Acid (ISR) Pathways

COS activates two distinct plant hormone signalling pathways:

• Salicylic acid (SA) pathway — Systemic Acquired Resistance (SAR): Upregulates Pathogenesis-Related (PR) protein genes, particularly PR1. SAR provides long-lasting, systemic protection against fungal and bacterial pathogens.
• Jasmonic acid (JA) pathway — Induced Systemic Resistance (ISR): Activates defence against insect herbivory, necrotrophic pathogens, and abiotic stress. Increases activity of defence enzymes CAT, POD, SOD, and PAL.

Research published in Scientific Reports (Nature Publishing Group) confirmed COS pretreatment at 50 mg/L applied 1 day before inoculation provided the strongest resistance to Tobacco Mosaic Virus in Arabidopsis, operating primarily through the SA signalling pathway. This priming effect means plants treated with COS are faster and stronger in their defence response to subsequent pathogen attack.

Antimicrobial Mode of Action

COS also exerts direct antimicrobial effects. Its high positive zeta potential (+70 mV) enables electrostatic binding to negatively charged microbial cell membranes, disrupting membrane integrity and inhibiting growth of a wide range of fungal and bacterial pathogens including:

• Botrytis cinerea (grey mould)
• Fusarium oxysporum (Fusarium wilt)
• Pythium spp. (damping-off)
• Alternaria alternata (early blight)
• Pseudomonas syringae (bacterial speck)
• Tobacco Mosaic Virus (TMV) and Cucumber Mosaic Virus (CMV)

Key Benefits of COS-AG for Agricultural Applications

1. Promotes Faster Germination and Vigorous Early Growth

Seed treatment with COS-AG (0.2–0.5% solution) significantly improves germination rate and seedling vigour. COS activates metabolic pathways that increase seed respiration rate, enzyme activity (amylase, protease), and energy mobilisation — giving seedlings a stronger start and more uniform stand establishment.

2. Enhances Root Development and Nutrient Uptake

COS stimulates root elongation, lateral root branching, and root hair formation, dramatically increasing the root surface area available for nutrient and water absorption. This supports sustainable agriculture goals by improving fertiliser use efficiency (FUE) — meaning lower input costs for the same or better yield.

3. Activates Natural Plant Immunity (ISR + SAR)

As detailed in the mechanism of action section above, COS-AG triggers both ISR and SAR pathways, providing broad-spectrum, systemic disease resistance. This reduces reliance on synthetic fungicides and bactericides while maintaining or improving crop health — a key benefit for organic and integrated pest management (IPM) programmes.

4. Improves Stress Tolerance (Drought, Salinity, Temperature)

COS improves plant tolerance to abiotic stresses including drought, high salinity, and temperature extremes by:

• Stimulating accumulation of osmoprotectants (proline, betaine)
• Reducing oxidative damage through increased antioxidant enzyme activity (SOD, CAT, POD)
• Improving stomatal regulation and water-use efficiency
• Enhancing chlorophyll content and photosynthetic efficiency under stress

5. Boosts Crop Yield and Produce Quality

Multiple field trials demonstrate that COS application improves yield across a wide range of crops. Results reported in peer-reviewed literature include:

• Rice: 8–15% yield increase with COS foliar spray at heading stage
• Wheat: improved grain filling rate and grain weight
• Tomato: 12–18% improvement in fruit set and marketable yield
• Maize: faster germination, greater root biomass, improved stress recovery
• Grapes: improved berry quality, reduced Botrytis incidence

6. Soil Microbiome Enhancement

COS improves soil health by stimulating beneficial microbial communities. It promotes populations of plant growth-promoting rhizobacteria (PGPR) and mycorrhizal fungi, improving nutrient cycling, organic matter decomposition, and long-term soil structure.

 

Application Methods, Dosage, and Use Rates

Application Method	Recommended Rate / Protocol
Foliar Spray	50–100 ppm (mg/L) — apply every 7–14 days during active growth
Seed Treatment (soaking)	0.2–0.5% w/v solution — soak seeds 4–12 hours before planting
Seed Coating	Mix COS with binder (CMC or starch); coat at 1–3 g COS per kg seed
Soil Drench / Irrigation	1–2 kg per hectare in adequate irrigation volume
Hydroponic / NFT	10–50 ppm in nutrient solution — monitor EC and pH
Biostimulant Formulation	0.5–2.0% active in final product formulation
Pre-plant Soil Amendment	1–2 kg/ha broadcast and incorporate 2–4 weeks before planting

 

Note: Application rates may vary by crop type, growth stage, and local conditions. Contact us for crop-specific guidance: steve@chitosanglobal.com

Crop-Specific Dosage Guide

Crop	Application	Recommended Rate	Timing
Rice	Foliar spray	50–100 ppm	Tillering, heading
Wheat	Foliar spray + soil	50 ppm foliar; 1 kg/ha soil	Seedling, jointing
Tomato	Foliar + soil drench	75 ppm foliar; 1.5 kg/ha soil	After transplant, flowering
Maize / Corn	Seed treatment + foliar	0.5% seed soak; 50–75 ppm foliar	Pre-plant + V3–V6
Grapes	Foliar spray	75–100 ppm	Bud break, pre-flower, fruit set
Lettuce / Leafy veg	Foliar + drip	50 ppm / 1 kg/ha	Weekly during growth
Tea	Foliar spray	50–75 ppm	New flush emergence
Flower / Horticulture	Foliar + substrate	50 ppm foliar; 1 kg/ha substrate	Biweekly
Organic systems	All methods	Approved rate per local certifier	As needed

 

COS-AG vs. Standard Chitosan

Feature	Chitosan Oligosaccharide HCl (COS-AG)	Standard Chitosan
Molecular Weight	< 3,000 Da — oligomeric	50,000–500,000+ Da — polymeric
Water Solubility	100% — no acid required	Requires acetic acid (pH < 6)
Plant Absorption	Rapid — penetrates cuticle & cell walls	Limited — large molecular size
Bioavailability	High — fast systemic distribution	Low — surface effect only
Application Concentration	50–100 ppm (very low rate)	1,000–5,000 ppm (higher rate)
ISR/SAR Activation	Strong — documented in peer-reviewed studies	Moderate — less mobile in plant tissue
Seed Coating	Excellent — forms uniform thin film	Good — may clump at higher MW
Organic Compliance	EU 2021/1165 compliant	Compliant (source-dependent)
Price per Application	Lower effective cost (lower use rate)	Lower price per kg, higher use rate

 

Source Comparison: Mushroom Origin vs. Insect (BSF) Origin

Feature	Mushroom (Vegetal) Origin	Insect (BSF) Origin
Raw Material	Oyster mushroom mycelium	Black Soldier Fly (Hermetia illucens) pupae
Vegan / Non-animal	Yes — 100% plant-based	No — insect-derived
Allergen Status	No shellfish / no insect allergen risk	Insect-derived; check local regulations
Batch Consistency	Excellent — controlled fermentation	Excellent — controlled rearing conditions
Heavy Metals	Very low — no marine contamination risk	Very low — BSF has excellent detox profile
Sustainability	Circular — uses agri-waste feedstock	Circular — upcycles organic waste streams
Best For	Organic, vegan, EU / US market	High-performance, cost-effective, industrial
Certifications	Vegan-certified available	Traceable, COA-backed

Learn more about Mushroom (Vegetal) origin chitosan and Insect (Black Soldier Fly) origin chitosan.

Core Agricultural Applications

Biostimulant Formulation Development

COS-AG is a premier active ingredient for manufacturers developing biostimulant products. Its water solubility, high charge density, and low application rate make it ideal for suspension concentrates (SC), soluble liquids (SL), water-dispersible granules (WDG), and soluble powders (SP). Learn more about chitosan in agriculture — benefits, functions, and dosages.

Seed Coating and Seed Treatment Products

COS forms a uniform, bioactive film on seed surfaces when used with appropriate binders. Seed-applied COS improves germination uniformity, seedling vigour, and early disease resistance reducing the need for fungicide seed treatments in integrated systems.

Organic Agriculture Inputs

COS-AG is compliant with EU Regulation 2021/1165 for use in organic production. It is a clean-label, natural-origin active that satisfies the increasing market demand for organic and residue-free crop protection solutions. Suitable for OMRI-listed product development (verify with certifying body for specific formulation).

Post-Harvest Treatment

COS is effective as a post-harvest treatment to reduce decay and extend shelf life of fresh produce. Its antimicrobial activity and elicitation of plant defence genes slow senescence and pathogen progression. See our chitosan edible coating page for formulation guidance on produce coating applications.

Water Treatment — Supporting Role

COS can also be utilised as a flocculant aid in agricultural water treatment and irrigation water purification. Its cationic charge assists coagulation of suspended particles and colloids. Learn about chitosan in water treatment.

Tank-Mix Compatibility Guide

Product / Input Type	Compatibility with COS-AG	Notes
NPK liquid fertilisers	Generally compatible	Test at recommended rates before bulk mixing
Humic / fulvic acids	Compatible	Enhances nutrient complexation
Amino acid-based biostimulants	Compatible	Synergistic — nutrient + immunity action
Biological fungicides (Trichoderma)	Compatible	Combine for enhanced disease suppression
Biological bactericides (Bacillus)	Compatible	COS + Bacillus = strong synergistic effect
Copper-based fungicides	Use with caution	Potential chelation — buffer pH to 5.5–6.5
Sulfur-based fungicides	Not recommended	pH incompatibility — apply separately
Strong alkaline products (pH > 8)	Not recommended	Degrades COS at high pH
Adjuvants / wetters	Compatible	Improves leaf coverage and absorption

 

Always conduct a jar test before large-scale tank mixing. Contact us for technical support: steve@chitosanglobal.com

Pricing, Ordering, and Bulk Supply

Package	Price	Shipping (USA)
25 g Sample	$75.00	Free delivery to USA
1 kg (Mushroom or Insect)	$176.00	Product + $8 import tariff + $90 shipping
5 kg – 25 kg Bulk	Contact for quote	Custom freight — email steve@chitosanglobal.com
25 kg + Industrial	Contact for quote	Global logistics, FOB and CIF options available

 

• Every order ships with a batch-specific Certificate of Analysis (COA)
• MSDS available on request for all orders
• OEM and white-label supply supported for biostimulant manufacturers
• Custom specifications (MW range, DDA, DP) available for large orders
• Global shipping — USA, EU, India, Asia, Middle East, Latin America

View wholesale pricing and volume discount structure | Email: steve@chitosanglobal.com | Call: +1 423-202-6145

Why Source COS-AG from Chitosan Global?

• Dual sustainable sourcing: Mushroom (vegan) and Black Soldier Fly origin — chosen for sustainability, not just cost
• Batch-specific COA: Every shipment includes a Certificate of Analysis verifying MW, DDA, zeta potential, moisture, and ash content
• FDA-registered facility: All products manufactured in an FDA-registered food facility with full batch traceability
• Technical support included: Free formulation consultation with purchase — we help you optimise COS application rates for your specific crop system
• Transparent total-cost pricing: All import tariffs and shipping costs itemised — no surprises at checkout
• Reliable supply: Consistent batch-to-batch quality from controlled production — not spot-market sourcing

Read about our responsible supply chain commitment, environmental health & safety standards, and ESG strategy.

Frequently Asked Questions — Chitosan Oligosaccharide Hydrochloride (COS-AG)

What is the CAS number for Chitosan Oligosaccharide Hydrochloride?

The CAS number is 148411-57-8. This is the registered identifier for Chitosan Oligosaccharide Hydrochloride (COS·HCl). The free-base form (chitosan oligosaccharide) has a different CAS number.

What does ‘COS-AG’ mean?

COS-AG stands for Chitosan Oligosaccharide Agriculture Grade. The ‘AG’ designation indicates the product is formulated and quality-controlled for agricultural applications including foliar sprays, seed treatments, and soil applications, as distinct from food or pharmaceutical grades.

What is the difference between chitosan oligosaccharide and standard chitosan?

Standard chitosan is a high molecular weight polymer (50,000–500,000+ Da) that requires acidic conditions for dissolution. Chitosan oligosaccharide has a much lower molecular weight (< 3,000 Da), is fully water-soluble at neutral pH, and is absorbed much more rapidly by plants. At the cellular level, COS triggers immune responses at much lower concentrations (50–100 ppm vs 1,000–5,000 ppm for polymer chitosan).

What is zeta potential and why does +70 mV matter in agriculture?

Zeta potential measures the surface electrical charge of particles in suspension. A value of +70 mV indicates a strongly cationic (positively charged) molecule. In agriculture, this high positive charge enables COS to bind tightly to negatively charged plant cell membranes, pathogen cell walls, and soil particles, maximising biological interaction and efficacy at very low application rates.

Is Chitosan Oligosaccharide Hydrochloride approved for organic farming?

Yes. COS-AG is compliant with EU Regulation 2021/1165, which governs substances permitted in organic production. It is a natural-origin, biodegradable compound. For OMRI listing or NOP (USDA Organic) compliance, the specific formulated product must be assessed by the certifying body. contact us for documentation to support your certification process.

What is the recommended foliar spray concentration?

The standard foliar spray rate is 50–100 ppm (mg/L). To prepare a 100 ppm solution: dissolve 100 mg of COS-AG powder in 1 litre of clean water and mix thoroughly. Apply with standard spray equipment, targeting complete coverage of leaf surfaces. Repeat every 7–14 days during active growth or at key crop development stages.

Can COS-AG be tank-mixed with fertilisers?

COS-AG is generally compatible with NPK liquid fertilisers, humic acids, amino acids, and biological agents such as Trichoderma and Bacillus. Avoid tank-mixing with strong alkaline products (pH > 8) or sulfur-based fungicides. Always conduct a jar compatibility test before large-scale application.

What is the shelf life of COS-AG?

Shelf life is 24 months from the date of manufacture when stored in a sealed, moisture-proof container in a cool (below 25°C), dry, well-ventilated area away from direct light and heat. Avoid humid environments as COS powder is hygroscopic.

What is the difference between Mushroom origin and Insect origin COS-AG?

Both sources produce COS-AG with equivalent technical specifications (MW, DDA, zeta potential). The key difference is the raw material: Mushroom (Vegetal) origin is 100% plant-based and suitable for vegan-certified formulations, while Insect (Black Soldier Fly) origin offers excellent batch consistency from a highly traceable, sustainable circular economy feedstock. Choose Mushroom for vegan/non-animal product claims; choose Insect for cost-performance and sustainability credentials.

How does COS compare to carboxymethyl chitosan (CMCS) for agriculture?

COS-AG and Carboxymethyl Chitosan (CMCS) are both water-soluble chitosan derivatives but serve different primary functions. COS-AG is the preferred choice for plant immunity activation and biostimulant applications due to its small molecular size and high positive charge. CMCS is amphoteric (both positive and negative charge) and is more suited to seed coating formulations, post-harvest edible coatings, and soil moisture retention. Many formulators use both in complementary roles.

Do you offer custom molecular weight or deacetylation specifications?

Yes. For orders of 5 kg and above, we can work with our manufacturing partners to provide COS-AG within a specified MW range or DDA window. Custom specifications are subject to lead time (2–12 weeks) and minimum order quantities. Contact steve@chitosanglobal.com with your technical requirements.

Can I request a sample before placing a bulk order?

Yes. A 25 g sample is available at $75.00 with free delivery to the USA. This allows you to test dissolution, compatibility with your formulation system, and biological activity before committing to a bulk purchase.

Is a Certificate of Analysis (COA) available?

Yes. A batch-specific COA is available for every order, verifying molecular weight, degree of deacetylation, zeta potential, moisture content, ash content, and insoluble substance. An MSDS is also available on request. Download links are provided on this product page and emailed with every order confirmation.

 

Related Products & Resources

Explore other Chitosan Global products that complement or compare with COS-AG:

• Chitosan Oligosaccharide — Hub Page — Full educational overview of COS across all grades
• Chitosan in Agriculture — Benefits, Functions, Dosages — Comprehensive application guide
• Mushroom (Vegetal Origin) Chitosan — Vegan, allergen-free chitosan source overview
• Insect Origin (Black Soldier Fly) Chitosan — BSF sustainability story and product range
• Carboxymethyl Chitosan (CMCS) — Amphoteric derivative for seed coating and edible films
• Quaternary Chitosan (HTCC) — Permanently cationic derivative for antimicrobial fibre and textiles
• Chitosan Hydrochloride — Water-soluble polymer for biomedical and agricultural use
• Chitosan Edible Coating — Post-harvest coating for fresh produce
• Wholesale Pricing — Volume discounts and bulk supply terms
• Frequently Asked Questions — General chitosan product questions