Preservatives

Water-based coatings contain water, organic binders, additives, and other nutrients that can support the growth of bacteria, fungi, and yeast. Without proper preservation, microbial contamination can occur during manufacturing, storage, and transportation, leading to:

• Unpleasant odors
• Viscosity loss
• Color changes
• Gas formation and swelling of containers
• Reduced product performance
• Shortened shelf life

A suitable preservative system helps maintain product quality and stability throughout its lifecycle.

In-can preservatives protect the coating during production, storage, and transportation by controlling microbial growth inside the container.

Dry-film preservatives protect the cured coating film after application, preventing the growth of mold, algae, and fungi on the painted surface.

Many exterior coatings require both types of protection for complete microbial control.

The selection depends on several factors:

• Product pH
• Storage temperature
• Raw material contamination risk
• VOC requirements
• Regulatory requirements
• Target shelf life
• Application type

For example:

Insufficient dosage may result in:

• Bacterial contamination
• Mold growth
• Product spoilage
• Reduced shelf life
• Customer complaints
• Production losses

A preservative should always be used at the dosage recommended by the supplier and verified through microbiological testing.

Yes. Overdosing may lead to:

• Increased formulation costs
• Regulatory compliance issues
• Potential compatibility problems
• Changes in product odor or appearance

The goal is to achieve effective protection at the lowest effective dosage.

Yes.

Modern water-based formulations increasingly require formaldehyde-free preservation systems.

Products such as SIP-03 and SIP-20 are formulated without formaldehyde and phenolic compounds, making them suitable for environmentally conscious and low-emission coatings.

When properly selected and used at recommended levels, preservatives generally have minimal impact on:

• Viscosity
• Color
• Gloss
• Adhesion
• Drying time

Compatibility testing is always recommended before commercial production.

Common signs include:

• Foul or rotten odor
• Increased or decreased viscosity
• Gas generation
• Swollen packaging
• Surface mold growth
• Product separation

Microbiological analysis can confirm contamination and identify the responsible microorganisms.

Although high pH can inhibit many microorganisms, some bacteria and fungi have developed resistance and can survive in alkaline environments.

For this reason, even coatings with a pH above 9 should contain an effective preservative system, especially when stored for extended periods or exposed to high temperatures.

The actual shelf life depends on:

• Formulation composition
• Manufacturing hygiene
• Packaging quality
• Storage conditions
• Preservative type and dosage

Under proper conditions, a well-preserved water-based coating can typically achieve a shelf life of 12–24 months or longer.

High temperatures accelerate microbial growth and increase contamination risks during storage and transportation.

In regions where warehouse temperatures may exceed 40°C, high-performance preservatives such as SIP-05 and SIP-20 provide enhanced protection and help ensure long-term product stability.

To receive an accurate recommendation, customers should provide:

• Product type
• pH value
• Storage temperature
• Target shelf life
• Existing preservative system
• Packaging type
• Production process details
• Regulatory requirements

This information enables suppliers to recommend the most effective and cost-efficient preservation solution.