Shipping containers

Shipping containers are the foundation of international trade. Millions of TEU (twenty-foot equivalents) are transported by sea annually with goods of all categories. Containers often require quarantine treatment: to destroy pest insects, mold, bacteria or remove odors from previous cargo.

Traditional fumigation with methyl bromide or phosphine leaves toxic residues, requires special permits and long degassing. Ozonation is an eco-friendly alternative: ozone decays to pure oxygen without contaminating cargo or the environment.

Important for importers: Container ozonation is recognized by phytosanitary services of many countries as an alternative to chemical fumigation. This allows treatment of cargo sensitive to chemical residues: food products, textiles, electronics.

Problems solved by ozonation

Shipping containers face a number of problems related to long transport and storage:

Pest insects — quarantine species imported with cargo from other countries
Mold and fungi — develop with temperature fluctuations and high humidity
Bacterial contamination — especially relevant for food cargo
Odors — from previous cargo (fish, chemicals, fertilizers) or mold
Quarantine requirements — mandatory treatment before import into the country

Ozone vs traditional fumigation

Comparison of container treatment methods

Parameter	Ozonation	Methyl bromide	Phosphine
Toxic residues	No	Yes (carcinogen)	Yes (highly toxic)
Treatment time	12-24 hours	24-48 hours	72-120 hours
Degassing	2-4 hours	24-48 hours	48-72 hours
Impact on ozone layer	No	Yes (banned in EU)	No
Food cargo	Yes	Limited	No
Electronics	Yes (with caution)	Yes	Yes
Special permits	No	Yes	Yes

Container ozonation technology

Container inspection

Check door seal tightness, ventilation openings. If necessary — temporary sealing with tape or film.

Parameter calculation

Determine container volume, target pest type, required ozone concentration. Standard 20-foot container — about 33 m³.

Equipment connection

Install ozonator with gas supply inside container through technical opening or door gap. Seal the entry.

Ozonation

Supply ozone until target concentration is reached (50-100 mg/m³ for insects). Maintain concentration for 12-24 hours.

Degassing

Turn off ozonator, open container doors. Natural or forced ventilation for 2-4 hours.

After degassing, ozone concentration drops to safe levels (<0.1 mg/m³). Cargo is ready for unloading and use without additional treatment.

Container treatment modes

Ozonation parameters for various purposes
Treatment goal	Concentration	Exposure time	Notes
Insects (adults)	30-50 mg/m³	12-18 hours	Most species
Insects (all stages)	50-100 mg/m³	18-24 hours	Including eggs and larvae
Mold and fungi	20-30 mg/m³	8-12 hours	From surfaces
Bacteria	15-25 mg/m³	4-8 hours	99.9% inactivation
Odor removal	10-20 mg/m³	4-6 hours	Odorant neutralization
Complex treatment	50-80 mg/m³	24 hours	All factors

For quarantine pests (bark beetles, weevils, flour beetles) maximum mode is recommended: 80-100 mg/m³ for 24 hours. This guarantees destruction of insects at all development stages, including eggs inside wood or grain.

Efficiency against pests

Destruction of pest insects with ozone (80 mg/m³, 24 hours)
Pest	Adults	Larvae	Eggs
Bread beetle	100%	100%	100%
Grain weevil	100%	100%	99.9%
Flour beetle	100%	100%	100%
Rice weevil	100%	100%	99.9%
Tobacco beetle	100%	100%	100%
Wood beetle	100%	99.9%	99.5%
Clothes moth	100%	100%	100%

Mechanism of action: Ozone destroys insect cell membranes at the molecular level. Unlike chemical pesticides, resistance to ozone does not develop — this is a fundamental physicochemical effect.

Container types and treatment specifics

Dry containers (DC)

Standard treatment. 20-foot — 33 m³, 40-foot — 67 m³. Require sealing of ventilation openings.

Refrigerated (RF)

Treatment with refrigeration unit off. Good tightness. Caution with electronics.

Ventilated

Require temporary sealing of all ventilation openings. Higher ozone consumption.

Open-top

Treatment after covering with tarp. Perimeter sealing. Partial leakage possible.

Equipment calculation by container size
Container type	Volume	Ozonator capacity	Concentration build-up time
10 feet	16 m³	20-30 g/h	1-2 hours
20 feet	33 m³	30-50 g/h	2-3 hours
40 feet	67 m³	50-80 g/h	3-4 hours
40 feet HC	76 m³	60-100 g/h	3-5 hours
45 feet	86 m³	80-120 g/h	4-5 hours

Application for various cargo

Ozonation is suitable for most cargo categories:

Grains and legumes — destruction of storage pests without chemical residues
Nuts and dried fruits — preservation of appearance and taste
Coffee and cocoa — mold neutralization without affecting aroma
Spices — quarantine treatment before import
Textiles — removal of warehouse storage odors, mold
Wood and lumber — destruction of bark beetles and wood borers
Paper and cardboard — prevention of fungal damage

Limitations: Treat cargo with rubber seals with caution (ozone accelerates rubber aging), unprotected electronics, fresh fruits and vegetables (may be damaged at high concentrations).

Ozone fumigation economics

Cost of treating a 40-foot container

Cost item	Ozonation	Chemical fumigation
Equipment (one-time)	150-300 thousand ₽	Not required (service)
Treatment cost	500-1000 ₽	15-25 thousand ₽
Downtime	24-28 hours	72-120 hours
Documentation	Treatment certificate	Fumigation certificate
Staff	1 person (training)	Licensed team

With regular container treatment, ozonator equipment payback is 10-20 treatments. For terminals and logistics companies with high container turnover, savings amount to hundreds of thousands of rubles per month.

Equipment for containers

High-capacity industrial ozonators are used for container fumigation:

Ozone generators 50-200 g/h — for 20-40 foot containers
Supply systems — hoses, fittings, sealing gaskets
Ozone analyzers — real-time concentration monitoring
Timers and controllers — process automation
Mobile complexes — on trailer or van base

For terminals: Stationary ozonator complexes allow simultaneous treatment of multiple containers. Pipeline system supplies ozone to containers on the site, central control panel manages the process.

Regulatory aspects

Ozonation as a quarantine treatment method is recognized in many countries:

ISPM-15 — allows alternative methods for wood packaging treatment
EPA (USA) — ozone registered as antimicrobial agent
EU — ozonation approved for organic products
Rosselkhoznadzor — accepts ozonation certificates for quarantine control
SanPiN — ozone approved for food product disinfection

When exporting/importing, check destination country requirements. In most cases, ozonation is accepted as an alternative to chemical fumigation with proper documentation: treatment certificate indicating concentration and exposure time.

Safety requirements

Treatment only on open areas or ventilated hangars
Fence treatment area, post warning signs
Personnel — at least 10 m from operating ozonator
When entering container before degassing — respirator with carbon filter
Concentration monitoring with analyzer before allowing people
Emergency shutdown — upon detection of leak or malfunction

Ozone MAC: 0.1 mg/m³ in work zone. At concentrations above 1 mg/m³ — respiratory irritation. At 10+ mg/m³ — health hazard. Always use analyzers for monitoring.