How to Disinfect Marble Countertops

Considering the COVID-19 pandemic, many of us are reconsidering how we go about our cleaning routines. This and other recent health scares shed light on how paramount it is to maintain clean and safe food-prep surfaces especially. With that being said, there are special considerations to keep in mind when it comes to cleaning and disinfecting natural stone such as marble. Despite that glassy finish, marble is quite a porous material, allowing liquids to seep beneath the surface can stain the stone if left untreated. On top of that, marble is susceptible to chemical etching by acidic chemicals such as vinegar, tomato sauce and red wine, among others. This means owners of natural-stone countertops need to be a little more careful when it comes to cleaning and disinfecting their counters. But first, let's go over the differences between cleaning and disinfecting, and why both are important processes:

Cleaning VS Disinfecting According to the CDC:

There are two methods for sanitizing a surface that the CDC makes an important distinction between. Cleaning a surface means physically removing germs and organic material with the potential to grow bacteria, reducing their numbers on the given surface. Disinfecting works instead by killing the germs that are left after a surface has been cleaned. The CDC's guidelines recommend both processes to help the spread of infectious disease. Daily marble sanitizing routine:

1. Clean the surface with a stone-safe cleaner to clear all liquids and soil
2. For disinfecting – we recommend MicroGold® Multi-Action Disinfectant Antimicrobial Spray. It’s a sister brand of Granite Gold®; it kills 99.9% of viruses and bacteria, and has been tested and proven effective to kill the COVID-19 virus. It’s safe for use on sealed stone surfaces.
3. Allow the solution to sit on the surface for 3 minutes to kill viruses; 10 minutes for bacteria.
4. Make sure to maintain a proper seal on the surface

For more information, you can check out the CDC's guide on sanitizing surfaces here: https://www.cdc.gov/coronavirus/2019-ncov/prepare/cleaning-disinfection.html To help keep your countertops free of germs, it's always important to wipe away food and other organic spills or soil when they happen. This will help prevent the spread of foodborne illness as well as help to maintain the integrity of your protective seal (more on that below).

Avoid Common Household Cleaners on Marble:

The problem with most cleaners we have around our house is that they tend to be either too acidic (low pH) or too alkaline (high pH) for use on marble and other natural stone. Like we briefly touched on before, acidic chemicals will eat away at the protective seal on your stone, and if left sitting, will etch the surface of your countertop. We see it tossed around on supposed lifehack blogs all the time recommending vinegar for cleaning countertops, but this is not a great idea. Then, on the other side of the pH scale, alkaline cleaners such as bleach can also strip away your counter's seal and can lead to oxidizing on the surface of the stone if used incorrectly. Something like dish soap can cause issues as well, as most feature tallows that leave streaks of light film on the counter surface or build up overtime to haze the surface. That's why we highly recommend a pH balanced cleaner for use on stone, such as Granite Gold Daily Cleaner®. This will remove streaks while keeping your stone's seal intact.

Keep Your Stone Sealed:

With marble being the porous material it is, spills can lead to stains and bacterial growth beneath the surface that are difficult to remove. When your countertops were installed, they were treated with a protective seal that needs to be maintained as your counters are used. This protective seal acts as a barrier to block substances from seeping in, as well as being your first line of defense against etching. It's also important not to use overly abrasive cleaning implements like steel wool or scouring pads, opt instead for a microfiber cloth or stone-safe sponge. It's also a good idea to keep liquid containers off the counter where possible. Things like soap dispensers can leave rings of soap scum, and even cooking oil bottles can leave stains. The general recommendation for when to reseal your stone is between every 6 and 12 months, but this is highly dependent on use. To determine whether your marble needs to be resealed, you can perform the water test: Pour water (about 3 inches in diameter) on your marble in several locations and let it sit for 30 minutes. If you see a dark spot form, the water is penetrating the stone and it’s time to reseal.

How to Reseal Marble:

First, it's important to always thoroughly clean the surface of your granite with a stone-safe solution before applying a seal. Spray an even coating of your stone sealer in roughly 3-foot sections at a time and immediately work the solution into the stone with a lint-free cloth. It's important to not allow the sealer to dry on the surface, as this can lead to hazing in those areas. Next, buff the area with a fresh microfiber cloth, and wait roughly 20-minutes or until the surface is dry to the touch between applications. For best results, it's not a bad idea to repeat the process 2-3 times, especially in areas that see heavy use. Have more questions or concerns on how to care for your natural stone? Consider reaching out to our team of stone care experts with more than 50 years of stone-care experience at 1-800-475-7866. Be sure to check out our full line stone care products to make sure you're doing that beautiful stone justice.