Hong Thai turns to nuclear sterilisation after contaminated inhaler recall

Formula 2 recall prompts a change across the product line

Hong Thai is adopting nuclear technology to sterilise its herbal inhalers after Thailand's Food and Drug Administration found microbial contamination in Hong Thai Herbal Inhaler Formula 2, lot 332. The company began a nationwide recall of the affected lot and asked customers to return those products for refunds.

As of November 2, 2025, the response also included a partnership with the Thailand Institute of Nuclear Technology, known as TINT, and a promise to complete factory upgrades and new quality controls within seven days. Hong Thai said it accepted full responsibility for the incident and the inconvenience caused to customers and retail partners.

The change extends beyond the recalled batch. Hong Thai announced that it would introduce cold sterilisation irradiation across its entire product line. This process uses ionising energy to eliminate microbes without applying heat or sterilising chemicals, with the aim of preserving the essential oils responsible for the inhalers' scent and perceived medicinal properties.

The announcement came amid enforcement action at locations linked to the brand. Regulators and police seized more than 2 million herbal inhalers and related items from facilities in Bangkok and nearby provinces. The total value was reported in the hundreds of millions of baht, and authorities said some sites lacked proper manufacturing licences.

Hong Thai's response therefore addresses two practical needs: reducing microbial contamination in its products and bringing its production arrangements into compliance with licensing requirements. Irradiation is the company's proposed route to stronger product safety controls, while factory upgrades and licensing work address how and where the products are handled.

What customers were asked to return

The FDA's tests confirmed microbial contamination in Formula 2, lot 332. Hong Thai then began removing that lot from stores across Thailand and offered refunds to customers returning affected items.

The lot number identifies the batch covered by the recall. Hong Thai's plan to introduce irradiation is broader, covering its entire product line rather than only the batch that triggered the FDA alert.

The company's owner said Hong Thai would take responsibility for the incident. The recall also affected retail partners, who had to withdraw the products, alongside shoppers who had already bought them.

The main developments unfolded in this order:

• The FDA detected microbial contamination in Hong Thai Herbal Inhaler Formula 2, lot 332.
• Hong Thai began a nationwide recall of that lot and asked customers to return affected products for refunds.
• Regulators and police raided locations linked to the brand and seized more than 2 million inhalers and related items.
• Hong Thai announced its partnership with TINT and a plan to complete factory upgrades and new quality controls within seven days.

Why the raids raised licensing concerns

Authorities said some of the locations involved in the enforcement action were operating without proper manufacturing licences. The seizures covered herbal inhalers and related items at facilities in Bangkok and nearby provinces.

Hong Thai founder Theerapong Rabuetham said the company's core licensed site met standards. He explained that a separate space used for labelling and packaging had not yet completed its licensing process.

Theerapong said the company had rented extra space and brought in new machines to cope with a surge in orders. A new plant, built to approved plans, was awaiting final paperwork. He described the enforcement action as premature and said the seized products were not counterfeit.

According to Theerapong, labelling and bulk packing had taken place in a clean facility that was not yet fully licensed. His explanation centred on the status of the additional premises, while authorities identified missing manufacturing licences as a reason for enforcement.

How irradiation tackles contamination

TINT's treatment uses ionising energy from electron beam equipment and gamma rays from Cobalt 60. The energy disrupts the DNA of bacteria, fungi and spores so that they cannot reproduce. DNA carries the instructions that these organisms need to function and multiply.

Irradiation is widely used around the world to sterilise medical devices and reduce contamination in spices and dried foods. For Hong Thai's inhalers, which contain plant materials, the aim is to bring microbial levels within safe limits while preserving the scent and the physical and chemical profile of the oils.

The process is called cold sterilisation because it does not apply heat. That matters for ingredients such as menthol, camphor and essential oils, which contain volatile compounds. These are substances that readily evaporate and contribute to the smell of an inhaler.

Hong Thai's planned treatment is intended to preserve those compounds while controlling microbes. The process also avoids the use of sterilising chemicals, allowing microbial treatment without chemical residues from a sterilant.

Why TINT has two treatment options

TINT operates electron beam systems that deliver a controlled beam of high energy with shallow penetration. This makes them suitable for compact products and for processing large numbers of items.

Gamma irradiation from Cobalt 60 penetrates more deeply. That can suit packages that are dense or have irregular shapes, where energy must reach material farther inside the package.

TINT's engineers choose the treatment method according to the size and density of the product and the packaging around it. They also plan the radiation dose to meet a defined safety target. The dose is the amount of energy absorbed during treatment.

Both methods serve the same purpose: delivering enough energy to control the microbes of concern throughout the product. The choice depends on the item being treated and how the energy will reach it.

Why treatment happens after packaging

TINT will treat Hong Thai's finished products in their final packaging at a closed irradiation centre. Trained specialists will operate the process under international standards.

Treating an inhaler after it has been sealed reduces the risk of contamination returning during later handling, transport and storage. Recontamination is often a weak point in conventional sterilisation lines, because a product can encounter microbes again after an earlier cleaning or treatment step.

Before each run, dosimeters confirm the planned dose inside and around the product. Dosimeters measure radiation dose, helping the specialists check that the treatment reaches the intended areas.

Validation checks establish that the microbes of concern are inactivated to the target level. A typical cycle takes one to two days from intake to release, including handling and quality checks. The approach aligns with guidance from international bodies such as the World Health Organization and the International Atomic Energy Agency.

Will the inhalers become radioactive?

Radiation used for sterilisation is energy applied during treatment, rather than radioactive material left in the inhaler. After treatment, the product does not carry residual radiation and does not become radioactive.

This is established science reflected in policies from the World Health Organization, the International Atomic Energy Agency and national regulators. The process also leaves no chemical residues from sterilants because no sterilising chemicals are used.

Kamol Unchoo, manager of TINT's radiation processing centre, addressed public concerns about the technology. He said it eliminates microorganisms without leaving radiation in the product and is safe when operated under strict standards.

TINT's controlled process combines the treatment itself with dose planning, checks and validation. These steps allow specialists to assess whether the required amount of energy has reached the product and whether the microbial safety target has been met.

Hong Thai sets a seven day target

Hong Thai said factory upgrades and new quality controls would be completed within seven days. An exact calendar date for completion was not given. The promise places a short deadline on changes that the company says are needed to restore consumer confidence.

Theerapong said trust in the brand had fallen sharply and that rebuilding it would take time. He presented the TINT partnership as the quickest route back to safety and compliance that independent experts could verify.

TINT hopes the collaboration will establish a higher benchmark for Thai herbal goods and rebuild confidence both in Thailand and in export markets. Its role is to provide a controlled treatment process for the finished products, supported by specialist operation and quality checks.

For Hong Thai, the immediate tasks are to carry out the recall, complete the promised factory and quality control changes, and address the licensing issues identified during enforcement. The company's wider plan is to make irradiation part of how it treats every product in its line.

Key Points

• The FDA found microbial contamination in Hong Thai Herbal Inhaler Formula 2, lot 332.
• Hong Thai recalled the affected lot nationwide and asked customers to return products for refunds.
• Authorities seized more than 2 million inhalers and related items, with a reported value in the hundreds of millions of baht.
• Founder Theerapong Rabuetham said the core site was licensed, while an additional labelling and packaging space awaited licensing.
• Hong Thai partnered with TINT to introduce irradiation across its entire product line.
• The treatment uses electron beams or gamma rays from Cobalt 60 without applying heat or sterilising chemicals.
• Treated inhalers do not become radioactive or retain residual radiation.
• Hong Thai promised factory upgrades and new quality controls within seven days.