AMERSTAT® 25DM – Advanced Microbiocide Fuel Treatment for Marine Fuel Systems

Combat microbial contamination in your fuel systems with AMERSTAT® 25DM, a powerful and cost-effective microbiocide treatment designed for low sulfur marine fuels, including VLSFO, ULSFO, and bio-derived fuels. With proven performance against bacteria and fungi at the fuel-water interface, AMERSTAT 25DM ensures reliable engine operation, improved fuel quality, and protection against corrosion and filter clogging.

Key Benefits:

• Total Microbial Control: Eliminates bacteria and fungi that degrade fuel quality.


• Reduces Corrosion: Prevents acid-induced corrosion caused by sulfate-reducing bacteria.


• Minimizes Filter Plugging: Stops biomass buildup that clogs filters and injectors.


• Dual-Phase Kill: Active in both oil and water phases for comprehensive protection.


• Easy to Dose: Compatible with multiple fuel delivery methods and storage conditions.


• Cost-Effective: One solution for both initial and ongoing microbial protection.

Ideal For:

• Marine diesel, gas turbine, and auxiliary boiler fuel tanks


• Stored fuels with moisture buildup


• Preventive maintenance and reactive treatment of contaminated tanks

Please note that AMERSTAT 25 is no longer approved for sale within the European Union due to updated regulatory restrictions. As an alternative, we now offer MERGAL MC14 in 24 kg containers under Part Number 6980024.

MERGAL MC14 provides effective preservation performance and complies with current EU regulations. If you need further technical details or safety data sheets, please feel free to reach out.

Technical Specifications & Application Guide

AMERSTAT® 25DM is a concentrated oil-soluble biocide with a density greater than water, allowing it to migrate to the water phase at the bottom of fuel tanks where microbial colonies grow. The product is designed for residual and distillate fuels stored in ISO 8217 compliant systems.

Physical Properties:

• Appearance: Amber liquid


• Odor: Organic


• Density @ 25°C: 1.09 g/cm³


• Flash Point (PMCC): 96.1°C


• pH (1% solution): 6.5


• Solubility: Complete


• Storage: Avoid temperatures > 60°C or freezing

Dosage Guidelines:

• Routine Maintenance: 1:25,000 (1L per 25 tons of fuel)


• Initial Cleaning (Contaminated Systems): 1:12,500 (1L per 12.5 tons of fuel)


• Retreatment recommended every 4 weeks or with each new fuel delivery

Application Instructions:

• Preferred method: Add directly to the water bottoms via drain valve or tank sounding pipe before bunkering.


• Alternative methods: Slug feed from top ports or inject continuously during loading.


• Sampling & Testing: Inspect every 3–4 months using onboard Sulfate Reducers Test Set (PCN 1701019).

Packaging Options:

• 25-liter containers (PCN 6981402)


• 200-liter drums (PCN 6981428)


• U.S. EPA Registration No.: 56473-4


• For use outside EU and Canada. EU alternative: MERGAL MC14, Canada alternative: ACTICIDE 14