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TCCA 90 Uses and Applications: Comprehensive Guide to Trichloroisocyanuric Acid

What Is TCCA 90?

Trichloroisocyanuric acid (TCCA), commonly known as "TCCA 90" or "trichlor," is one of the most efficient chlorine-based disinfectants available. The "90" refers to its minimum available chlorine content of 90% — the highest among all solid chlorine disinfectants. Its chemical formula is C₃Cl₃N₃O₃, containing three active chlorine atoms bound to a cyanuric acid backbone.

When dissolved in water, TCCA slowly releases hypochlorous acid (HOCl) — the primary antimicrobial agent — while simultaneously releasing cyanuric acid, which acts as a chlorine stabilizer (UV protector). This dual-action mechanism makes TCCA uniquely suited for outdoor water treatment applications.

Key Properties

Property	Value
Chemical Formula	C₃Cl₃N₃O₃
Molecular Weight	232.44 g/mol
Available Chlorine	≥90%
CAS Number	87-90-1
UN Number	UN 2468 (Class 5.1)
pH (1% solution)	2.7–3.0 (acidic)
Water Solubility	1.2 g/100 mL at 25°C
Decomposition Temperature	225°C
Shelf Life	24 months (proper storage)

Product Forms & Particle Sizes

TCCA 90 is available in multiple physical forms, each optimized for different applications:

Form	Specification	Best Applications
Tablets	20g, 50g, 100g, 200g	Pool floating feeders, slow-release dosing
Granular (8–30 mesh)	0.85–3.0 mm	Long-term disinfection, cooling water, reservoirs
Powder (60+ mesh)	<0.25 mm	Surface disinfection, spray applications

Major Applications

1. Swimming Pool Disinfection

TCCA 90 is the most widely used pool chlorine worldwide. Its slow-dissolving tablet form provides continuous disinfection for 5–7 days per dose, while the cyanuric acid byproduct protects chlorine from UV degradation in outdoor pools.

Maintenance dosing: 1–3 mg/L free chlorine residual
Tablet dosing: 1 × 200g tablet per 10,000 L per week (typical)
Advantage over calcium hypochlorite: Lower pH impact, no calcium hardness buildup, UV-stabilized

2. Drinking Water Treatment

TCCA is approved by WHO and NSF/ANSI 60 for potable water disinfection. It is particularly valuable in:

Rural and remote water supply systems
Emergency and disaster relief water purification
Military field operations
Municipal water systems in developing regions
Dosage: ~1 g per 1,000 liters (to achieve 0.5–1.0 mg/L residual)

3. Industrial Circulating Cooling Water

Cooling towers and heat exchange systems are breeding grounds for algae, bacteria, and slime. TCCA effectively controls:

Sulfate-reducing bacteria (corrosion cause)
Iron bacteria (biofouling)
Fungi and algae (flow restriction)
Legionella bacteria (public health risk)
Continuous dosing: Maintain 0.5–1.0 ppm free chlorine
Shock dosing: 5–10 ppm for severely fouled systems

4. Aquaculture & Agriculture

TCCA is widely used in fish and shrimp farming for water disinfection and disease prevention:

Fish/shrimp ponds: 0.5–1.0 ppm for routine disinfection
Livestock housing: Surface spray at 200–500 ppm
Seed treatment: Low concentration soak to improve germination
Fruit & vegetable washing: 50–100 ppm (food-grade only)

5. Industrial Bleaching

In textile and paper industries, TCCA serves as an efficient bleaching agent:

Textile: Cotton, hemp, and synthetic fiber bleaching — gentler on fibers than sodium hypochlorite
Paper: Pulp bleaching and microbial control in paper mill water systems
Wool: Anti-shrink treatment — modifies disulfide bonds in wool fibers

6. Healthcare & Public Disinfection

Hospital surface and equipment disinfection (200–1000 ppm solutions)
Medical waste treatment
Public venue disinfection (schools, hotels, transport hubs)
Epidemic response — effective against bacteria, viruses (including enveloped viruses), and fungal spores

Dosage Quick Reference

Application	Target Residual	Dosage	Contact Time
Swimming pools	1–3 ppm free Cl	2–5 g per 1,000 L	Continuous
Drinking water	0.2–0.5 ppm	1 g per 1,000 L	30 min
Cooling water	0.5–1.0 ppm	1–2 g per 10,000 L/day	Continuous
Aquaculture ponds	0.5–1.0 ppm	0.5–1.0 g per 1,000 L	24 hrs
Surface disinfection	200–500 ppm	1 g per 2–5 L water	10–30 min
Emergency water	0.5 ppm	1 tablet (20g) per 1,000 L	30 min

Advantages of TCCA 90 Over Other Chlorine Sources

Advantage	Explanation
Highest available chlorine	90% — highest among all solid chlorine compounds
UV stabilization	Cyanuric acid byproduct protects chlorine from sunlight
Long shelf life	24 months with minimal degradation
Slow-release dosing	Tablets dissolve over 5–7 days, reducing labor
Lower pH impact vs Cal Hypo	Acidic pH (2.7) helps balance high-pH pool water
Cost per kg active chlorine	Lower than bleach, calcium hypochlorite, or chloramine-T
Broad-spectrum efficacy	Effective against bacteria, viruses, fungi, and spores

When NOT to use TCCA: TCCA releases cyanuric acid (CYA), which accumulates over time. In indoor pools, drinking water treatment requiring low CYA, or applications where CYA buildup is undesirable, calcium hypochlorite (which does not release CYA) is the better choice. See our TCCA vs Calcium Hypochlorite comparison.

Safety & Storage

Handling TCCA 90:

Strong oxidizer — store away from acids, ammonia, and organic materials
Wear PPE: chemical-resistant gloves, goggles, dust mask
Store in cool, dry, ventilated area below 30°C
Never mix with other chlorine products or chemicals in solid form
Always add TCCA to water — never water to TCCA
In case of fire: use large volumes of water only

Conclusion

TCCA 90 is a versatile, high-efficiency disinfectant with applications spanning from swimming pools to industrial cooling, agriculture, and healthcare. Its combination of 90% available chlorine, UV stabilization, slow-release capability, and long shelf life makes it the preferred choice for outdoor water treatment and export applications worldwide.

For certified TCCA 90 in granular, tablet, or powder form, contact Everglory Industrial — NSF, ISO 9001, and SGS certified manufacturer.

Frequently Asked Questions

Q: What does the "90" in TCCA 90 mean?

The "90" refers to the minimum available chlorine content of 90%. This is the highest chlorine concentration among all solid chlorine disinfectants, making TCCA the most concentrated chlorine source available.

Q: Is TCCA 90 safe for drinking water treatment?

Yes, TCCA is approved by WHO guidelines and certified under NSF/ANSI 60 for potable water treatment. Typical dosage is 1 g per 1,000 liters to achieve 0.2–0.5 mg/L residual chlorine. Always use certified food-grade TCCA for drinking water applications.

Q: How long do TCCA 90 tablets last in a pool?

A standard 200g TCCA tablet in a floating dispenser typically dissolves over 5–7 days in a residential pool, providing continuous chlorine release. Dissolution rate depends on water temperature, flow rate, and tablet size.

Q: Can TCCA 90 be used with calcium hypochlorite?

Never mix TCCA and calcium hypochlorite in dry form — this can cause a violent reaction. In pool water, they can be used at different times (e.g., TCCA for maintenance, Cal Hypo for shock), but always allow proper dissolving time between applications.

Q: What is the shelf life of TCCA 90?

TCCA 90 has excellent storage stability with a shelf life of more 24 months when stored in sealed, dry containers below 30°C. This is significantly longer than liquid bleach (3–6 months) and comparable to or better than calcium hypochlorite (18–24 months).