Got questions about Concrobium Mould Control?

We’ve got answers. And if you don’t see your question here, please contact us.

EPA Registration

Why is EPA registration important for an antimicrobial product like Concrobium Mould Control?

Any product claiming to eliminate or prevent fungi or mould requires registration with the US Environmental Protection Agency. Registration is issued after review of efficacy data.

Is Concrobium Mould Control EPA-registered?

Yes, Concrobium Mould Control’s EPA registration number is 82552-1.


I see Sodium Carbonate listed on the label. Is Concrobium Mould Control just Sodium Carbonate (washing soda) and water?

No. Sodium Carbonate is the listed “active ingredient” on the Concrobium Mould Control label, but in fact there are two other ingredients in the solution which, when combined with the sodium carbonate and the water, result in this patented tri-salt polymer that eliminates and prevents mould. (Sodium Carbonate and water alone are not effective against mould.) The solution contains no bleach, ammonia or VOCs. Our Material Safety Data Sheet is posted on our website.



Can’t I just use bleach to get rid of the mould in my house?

Bleach can be toxic and poses health risks to users and to occupants during and after use.
Also, bleach will not prevent the mould from returning to the cleaned surface. It may look clean once you’re done, but the mould will grow back within weeks.

Bleach is particularly ineffective at treating mould on porous surfaces such as drywall, lumber and grout.

I’ve already treated an area with bleach. Can I use Concrobium Mould Control now?

When bleach attacks surface mould, it leaves a carbon layer residue that prevents Concrobium Mould Control from penetrating to the mould roots or hyphae. This can limit the product’s effectiveness. If you’ve already treated a mouldy area with bleach in the past, you should first wipe the area down with warm water and detergent to remove the layer. Once the area is dry, apply Concrobium Mould Control as recommended in the usage instructions.

Can I add bleach to Concrobium Mould Control?

Concrobium Mould Control is ready to use. Any added substance will act as a dilution and affect Concrobium Mould Control’s efficacy.

Safety Precautions

Do I need to wear a mask when using Concrobium Mould Control?

Concrobium Mould Control does not contain any VOCs and does not off-gas. However, if you’re in an area with heavy mould growth, a mask would be a good idea to limit your inhalation of harmful mould spores. If fogging, it’s a good idea to avoid breathing in excessive moisture from the fog.

Do I need to evacuate the area when using Concrobium Mould Control?

No. Concrobium contains no ammonia, acids, bleach or VOCs. Evacuation of the area during use is not required.

Is Concrobium Mould Control safe around animals?

Yes. It leaves no residue that would be harmful to animals.

I can’t find your Material Safety Data Sheet (MSDS)?

To access the Material Safety Data Sheet and other technical information for Concrobium Mould Control, please click here.


How much Concrobium Mould Control do I need?

The product works as it dries, so the surface only needs to be lightly wetted for it to be effective. Avoid over-application as it can result in some white residue forming as the product dries. If you do get residue, just wipe it away with a Concrobium Mould Control-dampened cloth.

What kind of surface coverage can I expect from Concrobium Mould Control?

Surface coverage will depend on surface absorbency and application method. The more porous the surface (e.g., fabrics), the more product will be required. Raw construction materials like drywall, wood products and cinder blocks will be more absorbent than painted surfaces or smooth surfaces like vinyl or poured concrete. Fogging will give you the greatest coverage – 1/2 gallon will cover approximately 1,400 sq. ft. of surface area (the equivalent of all the walls, ceiling, and floor in a 20’ x 20’ room). If using a compression or garden sprayer, a fine mist nozzle should give you approximately 350-450 sq ft of surface coverage.

Using Concrobium Mould Control

Can I use Concrobium Mould Control in the kitchen?

Yes. Concrobium Mould Control contains no bleach, ammonia, alcohol or other harmful chemicals, making it appropriate for food-serving areas.

Can I use Concrobium Mould Control in the shower?

Yes. Concrobium Mould Control is an effective solution for eliminating and preventing mould in the shower. Repeated exposure to water may require more frequent applications to ensure microbial resistance.

Is Concrobium Mould Control septic safe?

Yes, it is! Concrobium Mould Control is non-toxic and is made up of water and food-grade, inorganic salts making it safe for septic systems.

Can I use Concrobium Mould Control outside?

Concrobium Mould Control was primarily designed to eliminate and prevent indoor mould. Two products for outdoor use that are non-toxic and bleach-free is Concrobium House & Deck Wash and Concrobium Mould Stain Eraser which are ideal ideal for cleaning mouldy exterior surfaces. These products are not registered antimicrobials. They do not eliminate or prevent mould growth.

How often should I apply Concrobium Mould Control to prevent mould growth?

Concrobium Mould Control bonds to the surface at a molecular level and is difficult to remove. However, if it has been applied to a surface that is continually exposed to water (e.g., leaking, washing, running water), you may need to reapply the product periodically to maintain protection against mould growth.

I sprayed Concrobium Mould Control on the surface and let it dry, but the mould is still there. Why?

Concrobium Mould Control contains no bleach or whiteners. Once you have sprayed the solution on the mouldy surface and allowed it to dry, the mould has been encapsulated and eliminated – in other words, your mould problem has been eradicated. If staining or residue remains, scrub with a Concrobium-dampened cloth or brush – or take other cosmetic steps to improve the look of the surface. Remember that once the cleaning step is complete it’s important to leave a layer of Concrobium Mould Control on the surface to provide mould resistance.

What technique do you recommend for applying Concrobium Mould Control?

Depending on the area or surface you are treating with Concrobium Mould Control, you can apply the solution by: spray bottle (small targeted areas); brush or roller (trim); pump sprayer (large, accessible areas like walls); or cold fogger (large, enclosed areas like basement or attics).

Will Concrobium Mould Control penetrate drywall / flooring / other barriers. What if the mould is growing behind the wall?

Concrobium Mould Control needs to make direct contact with the mouldy surface to be effective. If mould is suspected behind drywall you will need to remove the drywall to treat the area or create / find an opening into which Concrobium Mould Control can be sprayed or fogged. The solution will not penetrate a solid barrier.

How long does Concrobium Mould Control take to dry?

Drying time depends on humidity levels and temperature in the area as well as the surface to which the solution was applied. Generally it will dry in less than 2 hours. If you are painting on top of the Concrobium Mould Control application you should allow 24 hours of drying time. If fogging, open windows to accelerate drying and to facilitate air exchange after fogging is complete.

Will Concrobium Mould Control freeze?

Yes, Concrobium Mould Control can freeze in sub-zero temperatures. If it does freeze, the product can still be used after thawing and stirring or shaking it up.

Does Concrobium Mould Control expire?

Concrobium Mold Control does not expire.

We do not put any expiration dates for product sold in the US. In Canada, the printing of a specific expiration date is a regulatory requirement by Health Canada which is determined by manufacturer data. While we have chosen a 5-year period for marketing and merchandising reasons, in fact our testing data demonstrates that the product retains its Health Canada approved level of efficacy beyond the expiration window.

My front-end loading washing machine smells mouldy sometimes – can Concrobium Mould Control help?

We’ve had customers report good success treating the front rubber ring and others parts of front-end loaders … give it a try! (But just make sure it dries before running the unit again – remember Concrobium Mould Control works as it dries.)

What is the optimal temperture to apply Concrobium Mould Control?

The optimal temperature to apply Concrobium Mould Control is 10°C or 50°F. Remember, if the product does not get the chance to dry then it won’t get the chance to work.

How long will Concrobium Mould Control last?

One application should be satisfactory as long as there is no water or humidity problem in the area. More frequent application may be required for shower and bathtub applications (ie. where the area is exposed to running water) or in areas where there is excessive humidity or condensation.

Can Concrobium Mould Control be mixed with water?

No, the product is ready-to-use and should not be diluted.

Can I use a sprayer to apply Concrobium Mould Control?

Yes, compression or garden sprayers (available at local home improvement retailers) are an excellent way to cover large surfaces that are easily accessible. It is important to use the nozzle that creates the finest mist. After spraying, wipe off excess wetness to ensure an even coating of the solution.

Can I paint over Concrobium Mould Control?

Yes. Regular household paints adhere very well to Concrobium Mould Control-treated surfaces. If you wish to treat and then repaint a mouldy surface, first apply the solution to clean the affected area. Allow to dry and then repaint. To prevent regrowth, retreat the newly painted area with Concrobium Mould Control – ensuring first that the newly painted surface is dry.

If I’m painting a mouldy wall, do I need to treat with Concrobium Mould Control before priming?

Yes. To ensure that the mould on the surface does not grow through the paint or priming, you should first treat the mouldy surface with Concrobium Mould Control. Once it has dried, you can then proceed with your painting project. Remember, it’s a good idea to treat the finished wall with more Concrobium Mould Control after the paint has fully cured, to ensure long-lasting protection of that area from future mould growth.

I used Concrobium Mould Control and nothing seemed to happen. Am I doing something wrong?

When Concrobium Mould Control dries on the mouldy surface it encapsulates and crushes the cells right down to the root structure of the mould spores. This action is not visible, but you can be assured that it’s working. While you may be used to using bleach or bleach-based products that whiten the mould stain, this product contains no bleaches or whiteners so may require some mechanical action to remove the stain.

I used the product on damp basement walls where I have water coming in from outside. The mould came back after a week. What did I do wrong?

Concrobium Mould Control works as it dries. If the surface on which you’re applying the product is continuously wet, it may never get the chance to dry and may never therefore get a chance to work. Whatever the mould problem you’re having, you should always deal with the root cause of the water intrusion before using our product.

Does Concrobium have an odour?

Concrobium Mould Control is odourless.

Is Concrobium Mould Control safe to use around plants and greenery?

Yes, Concrobium Mould Control is safe to use around plants and greenery. Concrobium Mould Control do not require surrounding plants and grass be covered, however spraying directly onto plants is not recommended.  If significant over spray makes contact with plants you may wish to consider spraying or misting the plants with water.


On what surfaces can Concrobium Mould Control be used?

Concrobium Mould Control is EPA-registered for and effective on both hard and fabric surfaces, including wood, drywall, tile, stone, cement, masonry, fabric, upholstery and virtually any other household surface. If you’re uncertain, contact us  or test on an inconspicuous section.

Can I use Concrobium Mould Control on fabric?

Yes, Concrobium Mould Control is effective on fabrics. It is EPA-registered for use on both hard and fabric surfaces.

What do I do if the surface is badly stained?

Concrobium Mould Control is a very effective cleaner, though in some circumstances you may find that the mould stains left on a surface are embedded and very difficult to scrub away. In this case, ensure that the treated surface is completely dry so that the mould spores have been eliminated.

Next, address the cosmetic stain by, for example, painting a stained wall, or using a grout whitener on a mould-stained tile wall. Finally, to ensure that surface is protected against future mould growth, reapply Concrobium Mould Control and wipe the surface dry.

Will Concrobium Mould Control discolour the treated surface?

No, Concrobium Mould Control will not discolour hard or fabric surfaces, as there are no bleaching agents in the product. As with any cleaning solution, it’s always a good idea to test Concrobium Mould Control on an inconspicuous section first. NOTE: In our years of experience we’ve encountered just two surfaces that can have negative reactions to Concrobium Mould Control: suede and billiard balls. (We’re still not sure why someone would apply it to the latter!)

Is Concrobium Mould Control safe for food preparation areas?

Yes. Food contact surfaces should be wiped down before use.

Can Concrobium Mould Control be used on carpets?

Concrobium Mould Control is great for eliminating odours in carpets since its encapsulating action traps and eliminates odour-causing particles. It will not discolour the carpet, though it’s still a good idea to test on an inconspicuous section first just to be sure. If you suspect mould in your carpet, you should pull it back to see if mould is growing on the subfloor and underpadding as well.

Will Concrobium Mould Control remove mould from tile grout?

Because tile grout is porous, mould that has grown into it for some time may be very difficult to remove. Using Concrobium Mould Control in conjunction with a stiff bristle brush will get rid of most tile grout mould. However, if the mould has been there a long time, additional measures may be needed. First spray the area with Concrobium Mould Control to treat the mould. Then use a grout whitener to cover or remove the stain. Lastly, once dry and clean, use Concrobium Mould Control again to lay down the protective barrier.

Can Concrobium Mould Control be applied to wet surfaces?

It is best to allow surfaces to dry first before applying Concrobium Mould Control since excessive moisture or water on the surface can dilute the product and impact its efficacy.

Will Concrobium Mould Control harm artwork? Can I use it on mouldy artwork or papers that are mouldy?

Concrobium Mould Control should not harm paper or painted surfaces. However, common sense should be used if an item is of value. If fogging an area, it’s best to remove anything that you would not want to get wet. If unsure, test on an inconspicuous area first.

Will Concrobium Mould Control remove mould from caulking around my tub?

Concrobium Mould Control is effective in removing stains from most surfaces including caulking. Mould that has grown into the porous caulking surface may be difficult to remove, however. It may be more effective to strip out the old caulking, wipe the area down with Concrobium Mould Control and then re-caulk once the area is dry. You should then spray more Concrobium Mould Control on the caulk once it itself is dried. If you do not want to remove the caulking, spray the area with Concrobium Mould Control and allow to dry. Then treat any remaining stains with a whitening agent. Always follow up with more Concrobium Mould Control to provide the protective barrier against future mould growth.


When fogging Concrobium Mould Control, what contents should be removed from the room?

Prior to fogging Concrobium Mould Control, remove or cover any items you would not normally want to get damp, including paper, books and electrical equipment.

I have noticed some white residue after fogging on some flat surfaces – what is this?

Residue is a normal result of overapplication of Concrobium Mould Control on non-absorbent surfaces. It is the result of evaporation of the water content from the solution as it sits pooled on a surface. The residue can be easily wiped away with a cloth dampened with Concrobium Mould Control. Adjust application rates accordingly for subsequent applications.

What type of fogger or other applicator can I use?

You need to use a cold fogger, one without a heating element (i.e., NOT a thermal fogger). You can use any type of electric applicator as long as there is no heat introduced and the product will not be diluted by water. If using an airless sprayer, ensure that the nozzle chosen does not create too fine a mist as the product may evaporate before reaching the surface.


What is the difference between mould and mildew?

Technically mildew is the fungi that grow on plants. Most people refer to mould as a dry growth and mildew as a wet growth. Concrobium Mould Control is effective against both.

What types of fungi (mould or mildew) does Concrobium Mould Control treat?

Concrobium Mould Control works on all types of fungi/mould. Its physical mode of action doesn’t differentiate between the type of mould.

Using Concrobium Moisture Grabbers

Are Concrobium Moisture Grabbers safe to use around children and pets?

Concrobium Moisture Grabbers are self-contained pouches, therefore it is unlikely for the contents to spill or come in contact with children or pets. While the ingredients within the pouches do not contain harmful chemicals, it is best to keep pouches out of reach.

The pouch opened and the contents got on my skin, what do I do?

For most people, exposure to the contents should not pose any health effects or irritability.  However, if contents come in contact with skin rinse thoroughly with water.

Where should I use Concrobium Moisture Grabbers?

For those instances where it is impractical to use a traditional electric dehumidifier, Concrobium Moisture Grabbers were designed to be used in small, confined spaces (e.g. closets, bathrooms, cabinets, pantries, storage bin, safes, car and trucks, etc.).

Will Concrobium Moisture Grabbers dry out physical spots of water?

Concrobium Moisture Grabbers will not dry out physical spots of water (i.e. water that has resulted from a flood or leak). Like any desiccant product Concrobium Moisture Grabbers will only absorb excess moisture from the air.