Study highlights effectiveness of Tea Tree Oil in enhancing indoor air quality onboard marine vessels

Recent research conducted by the School of Engineering and Built Environment at Griffith University, Brisbane, Australia, underscores the effectiveness of Tea Tree Oil (TTO) in significantly reducing airborne bacterial and fungal aerosols. Controlled experiments featuring the Unitor™ Duct Air Treatment (DAT) demonstrated remarkable antimicrobial results, achieving over 80% inactivation of microbial aerosols within the first 24 hours, and progressing to near-complete eradication within a week.

Using advanced monitoring techniques, researchers meticulously tracked bioaerosol concentrations in sealed environments, including small rooms and large laboratory spaces. The study revealed TTO’s high effectiveness against gram-positive and gram-negative bacteria and various fungi. Additionally, the experiments highlighted its ability to neutralize odour-causing compounds and inhibit microbial growth, contributing to improved air quality. The gradual release of TTO vapours ensured prolonged antimicrobial action, making the solution suitable for diverse indoor environments requiring stringent bioaerosol control.

These findings are particularly relevant for improving Indoor Air Quality (IAQ) in the maritime industry, where confined spaces and limited ventilation can exacerbate health risks for crew members and passengers.

Addressing air quality challenges at sea

In recent years, the maritime sector has made notable strides in reducing greenhouse-gas emissions and advancing decarbonization efforts. However, another critical aspect of Environmental, Social, and Governance (ESG) compliance has received less attention – ensuring safe and healthy onboard environments for seafarers.

While achieving emissions targets is essential, safeguarding IAQ is equally vital for protecting human health. The importance of this cannot be overstated for seafarers who often spend months at sea, making their onboard environment their primary living space.

Marine Heating, Ventilation and Air Conditioning (HVAC) systems, when poorly maintained, can become breeding grounds for harmful microbes, including viruses, bacteria and mould. The Maritime Labour Convention (MLC) 2006 mandates that air-conditioning systems must be designed for easy cleaning and disinfection to prevent the spread of pathogens. This is particularly challenging in humid and warm climates, where allergens and odours can multiply rapidly, posing both immediate and long-term health risks.

Why IAQ matters

IAQ is frequently overshadowed by more tangible aspects of ship operations, but maintaining good air quality is essential for crew health and comfort, as well as operational efficiency. Poor air quality, caused by factors such as inadequate ventilation, pollution from engine emissions and bacteria/mould in HVAC duct systems, can lead to a range of health issues. These include respiratory conditions, headaches, fatigue and other conditions that can potentially compromise daily performance.

The American Thoracic Society and other health organizations confirm that exposure to particulate matter and Volatile Organic Compounds (VOCs) can significantly affect respiratory health, particularly in confined environments like ships. Studies indicate that pollutant levels onboard vessels can be two to five times higher than outdoor air, making proactive IAQ management essential.

In the maritime context, prolonged exposure to subpar air quality can impair crew alertness and decision-making, increasing the likelihood of accidents. Recent findings by the International Maritime Organization (IMO) also link poor IAQ to reduced productivity and increased absenteeism.

Combatting bacteria and infection risks

Mould and bacteria present serious health risks, requiring proactive measures to protect crew and passengers from exposure to airborne spores. Left untreated, mould growth in HVAC ducts can worsen air quality and trigger respiratory issues and allergic reactions.

The integration of Duct Air Treatment (DAT) units into onboard HVAC systems is a powerful solution for addressing these challenges. These systems prevent mould growth, neutralize bacteria and reduce viral activity. Additionally, DATs eliminate unpleasant odours at the source rather than merely masking them, maintaining a fresher and healthier onboard environment.

A powerful natural remedy

The Unitor™ DAT offers a natural, biodegradable and non-toxic solution comprising complex polysaccharides, surfactants, purified water and pure TTO. Derived from the leaves of the Australian tea tree, TTO is widely recognized for its antibacterial, antifungal and anti-inflammatory properties. It has long been a key ingredient in health and wellness products and has proven benefits for skin health and minor wounds.

In the context of air quality management, TTO's natural properties complement the effectiveness of Unitor™ DAT by disinfecting impurities in HVAC systems and preventing disease spread, in line with MLC2006 requirements. Wilhelmsen, an associate member of the Australian Tea Tree Industry Association (ATTIA), ensures the highest product standards by sourcing pure, organically grown, ATTIA COP-certified essential oil from the Tweed Valley in New South Wales. Rigorous testing ensures compliance with international chemical composition standards.

Scientifically proven efficacy

The experiments conducted at Griffith University demonstrated that TTO vapours delivered through Unitor™ DAT achieved over 80% microbial inactivation for bacteria and mould within 24 hours, with near-total eradication by day seven. The tests were performed in controlled environments designed to closely simulate real-world application conditions.

The findings revealed that TTO vapours effectively inhibit microbial growth while neutralizing odours and maintaining a fresher atmosphere. This not only contributes to compliance with health and safety standards but also supports crew well-being and operational efficiency. The controlled, gradual release of TTO ensures prolonged antimicrobial action, positioning it as a scalable solution for maintaining IAQ.

Unitor™ DAT is compatible with all HVAC systems, including ducted systems, air handling units, and packaged air conditioners, making it adaptable for a wide range of marine environments.

Conclusion

The maritime industry has made remarkable progress in addressing environmental concerns, but IAQ improvement remains a crucial frontier. Ensuring safe and healthy onboard air quality is essential for safeguarding seafarer and passenger health, improving operational efficiency and supporting ESG compliance. Wilhelmsen Ships Service, through its innovative use of Australian TTO in Unitor™ DAT, is setting new standards for IAQ control, offering both a natural solution and scientifically proven results for a healthier maritime environment.

Read the report from Griffth University below: