Is Microban Safe to Breathe? (Does it Off-Gas or Leach)

Microban could be seven different chemicals incorporated into household items according to their website.

You often see Microban listed as the antimicrobial in flooring, countertops, carpet padding, stone sealers, and paints.

Note: I’m not covering their cleaning products, isolated disinfectant sprays, or industrial products.

Microban no longer offers triclosan (source).

Whether Microban off-gasses VOCs and is safe to breathe in, depends on which chemical was used.

When a product mentions that it includes Microban, they don’t say which chemical is used.

Here are the possible Microban chemicals.

Microban Antimicrobial Chemicals

1. Silver ion

This is the Microban chemical I see most often in consumer products.

It’s a non-nano silver ion used in polymers, coatings like powder-coated door handles, paints, light switches, bed rails, grout, flooring, food storage containers, home textiles like bedding and hospital gowns, water tanks, and dishwashers.

“The antimicrobial active ingredient generally used in paints and coatings is silver ion — it’s well proven, offers excellent efficacy, and is suitable for use in all types of paints and coatings in a wide range of applications.” Jennifer Collier, Partner Development Manager of BioCote. 

Off-gassing Potential: Silver ions do not off-gas, as they are non-volatile. They remain bound within the materials they are embedded in, such as coatings, textiles, or polymers.

Safety: Safe to breathe in when in solid form as there is no off-gassing. Silver ion particles are not airborne unless the material is in dust form or they are disturbed in a way that generates dust (e.g., cutting or sanding), says Dr. Mudgal, Toxicologist.

It is in powder form when it is found in concrete-based grout (or thinset). This means there could be a risk of inhaling airborne particles during the application or mixing of the grout, says Dr. Mudgal. Therefore, precautions such as wearing masks during handling and mixing should be taken to minimize the risk of inhalation.

2. Quat-silane–based 

Quat-silane–based antimicrobials for polyurethane foam and coatings. 

Off-gassing Potential: Quat-silane compounds can off-gas VOCs, especially when used in polyurethane foam and coatings. These VOCs can be released over time, particularly when the material is new, says Dr. Mudgal, Toxicologist.

Safety: The presence of antimicrobial additives such as quat-silanes could potentially contribute to or exacerbate these effects of off-gassing from the polyurethane itself, though the polyurethane base is the primary source of VOCs, says Dr. Mudgal.

Note that polyurethane foam always off-gasses low levels of VOCs, polyurethane coatings always off-gas when wet, though some are 0-VOC when cured.

3. “Ascera” 

This is a chemical that is not revealed – they say it’s similar to acids found in nature.

It’s used in solvent-based coatings/paints and in polymers.

Microban specifically holds a patent for a benzoic acid + terephthalic acid or quat silane antimicrobial for textiles (which may not be Ascera since Ascera if for coatings and polymers).

Some other natural acids used as antifungals in paints (though not necessarily used by Microban) include Benzoic acid, Sorbic acid, Potassium Sorbate, Pimaric Acids, and p-Hydroxybenzoic acid esters (parabens).

Off-gassing Potential: Since Ascera is described as being similar to natural acids, it could have some potential to off-gas.

The off-gassing would depend on the specific formulation and concentration, says Dr. Mudgal, Toxicologist.

Safety: Without specific details on the chemical composition, it’s hard to determine exact safety, but natural acids could release minimal VOCs, says Dr. Mudgal.

4. Sodium pyrithione 

This is used in water-based coatings.

Off-gassing Potential: Sodium pyrithione may release some VOCs in water-based coatings, but its volatility is relatively low. Most of the compound remains stable in the product, says Dr. Mudgal, Toxicologist.

Safety: Safe in most applications but direct inhalation of powdered sodium pyrithione can be harmful, potentially leading to respiratory irritation. In coatings, the risk is minimal as it is not easily airborne, says Dr. Mudgal.

5. Zinc pyrithione 

A common preservative in paint, also used in other coatings, textiles, polymer products, artificial turf, caulks and sealants, and cement.

Off-gassing Potential: Zinc pyrithione has low volatility, meaning it does not readily off-gas at room temperature. It remains stable and solid under typical conditions, says Dr. Mudgal, Toxicologist.

Safety: Generally safe when embedded in coatings or polymers, but if it is in powder form (like in dry cement), inhalation can be hazardous. Direct inhalation of zinc pyrithione particles should be avoided as it can cause respiratory irritation, says Dr. Mudgal, Toxicologist.

Other ingredients in dry mix cement are also hazardous, so proper PPE should already be used here.

6. “MicroGuard”

This Microban chemical is not revealed, and there are no hints as to what it could be, apart from the fact that it is not a metal.

This is recommended for many applications, including roofing membranes, car seating, decking, mattresses, luxury vinyl tiling (LVT), wallcoverings, upholstery, and awnings. It is integrated into PVC, PU, and EVA plastics. 

Some known antimicrobials used in luxury vinyl tile/plank include:

Poly hexamethylenediamine guanidine hydrochloride (PHMG), Nisin or Triclosan, silver (the most commonly used antibacterial agent) (source), Phenylthiourea derivatives, Copper and Cadmium complexes derived from thiourea compounds, zinc, zeolite (source), Peptides and cationic compounds, ionic liquids, especially those containing imidazolium cations with long alkyl chains, ionic liquids, HdmimDMSIP and OOMmimPF6 (source).

That doesn’t mean that MicroGuard is one of these chemicals on the list.

Off-gassing Potential/Safety: The exact chemical composition of MicroGuard is not disclosed, so it’s difficult to assess off-gassing potential. The safety for inhalation cannot be definitively assessed, says Dr. Mudgal.

7. “Ultra-Fresh“

Microban also acquired Ultra-Fresh.

Ultra-Fresh is used in textiles, plastics, carpets, foams, coatings, and more.

Ultra-Fresh is US EPA registered, BPR compliant and Oeko-Tex listed, and complies with all regulatory requirements of each country where it is sold.

Based on a 2013 SDS from Thompson Research Associates, the company that owned Ultra-Fresh before Microban bought it, it is an isothiazolinone (or was in 2013).

Safety/toxicity: As per the available SDS from 2013, the compositional chemical is 2-N-octyl-4- isothiazolin-3-one (OIT), a common isothiazolinone compound (CAS RN: 26530-20-1), used in various products, known for controlling microbial growth but also as a skin and respiratory sensitizer.

It has low off-gassing and VOC potential, meaning it doesn’t readily emit harmful gases at room temperature.

However, inhalation risks exist if OIT-containing products are aerosolized during activities like spraying or sanding. Proper handling, ventilation, and protective equipment are essential to minimize exposure and ensure safety, says Dr. Mudgal.

Corinne Segura is an InterNACHI-certified Healthy Homes Inspector with certifications in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes. You can book a consult here.