Moss on roofs - Ask Extension
I see that moss out is made with sulfuric acid. I don’t want my birds and squirrels to get in that. What do you recommend as a benign moss killer? T...
Knowledgebase
Moss on roofs #790453
Asked May 12, 2022, 1:06 PM EDT
I see that moss out is made with sulfuric acid. I don’t want my birds and squirrels to get in that. What do you recommend as a benign moss killer? Thank you so much.
Lane County Oregon
Expert Response
Hello,
All other moss killers use some type of acid whether it is fatty acids or citrus acid.
First, I am assuming you are talking about "Moss-out for Roofs and Structures" with zinc sulfate as the active ingredient. There are other Moss-Out products with fatty acid soaps: (1. Lilly Miller Moss Out! Roofs & Walks Concentrate and 2. Lilly Miller Hose'n Go! Moss Out! Roof and Walks Ready-To Spray). There is also a Safer Brand that uses fatty acid soaps.
Additionally, there are other products with d-Limonene (which has citrus acid, e.g., Worry Free Moss and Algae Control) that do not use sulfuric acid but use other acids. These products have not been as effective as zinc sulfate, but you may have success with repeated use. You have to be careful with the concentrated products as well, in terms of getting them in your eyes, as they can cause severe eye damage. But, in general, once diluted, they become eye irritants. Be sure to read the label carefully.
For information only: the active ingredient of the Moss-out product you are talking about is zinc sulfate (a granule) and not sulfuric acid (a liquid). Yes, a diluted sulfuric acid solution is used to convert zinc carbonate to zinc sulfate to make the product (See link below). The instructions do warn the students to wear eye protection but then says the concentration of sulfuric acid used (1 mol per dm-3 (1 mol of sulfuric acid = 98 grams (about 3.5 wt. ounces) and 1 dm-3 = 100 ml or about 3.4 fl. oz.) is "an irritant". However, the label and SDS does say the Moss-out granules cause serious eye damage if they get into your eyes. As with the concentrated products above, the risk decreases substantially once you dilute them in water. I would dilute the product in water and spray with a backpack spayer. I would also recommend you wear safety glasses when handling or applying any of these products.
Since the Moss Out is highly unlikely to get into the eyes of the birds or the squirrels, I do not believe it would be harmful to them, especially once the product dries which should only take a few minutes if sprayed in the afternoon sun.
https://edu.rsc.org/download?ac=12717#:~:text=Making%20zinc%20sulfate&text=Zinc%20sulfate%20crystallises%20from%20aqueous,carbonate%20with%20dilute%20sulfuric%20acid.
The main environmental concern with Zinc Sulfate when used on roofs is that the zinc can be harmful to salmon and other fish if it gets washed off the roof into the sewar drains.
I hope this helps. Good luck.
All other moss killers use some type of acid whether it is fatty acids or citrus acid.
First, I am assuming you are talking about "Moss-out for Roofs and Structures" with zinc sulfate as the active ingredient. There are other Moss-Out products with fatty acid soaps: (1. Lilly Miller Moss Out! Roofs & Walks Concentrate and 2. Lilly Miller Hose'n Go! Moss Out! Roof and Walks Ready-To Spray). There is also a Safer Brand that uses fatty acid soaps.
Additionally, there are other products with d-Limonene (which has citrus acid, e.g., Worry Free Moss and Algae Control) that do not use sulfuric acid but use other acids. These products have not been as effective as zinc sulfate, but you may have success with repeated use. You have to be careful with the concentrated products as well, in terms of getting them in your eyes, as they can cause severe eye damage. But, in general, once diluted, they become eye irritants. Be sure to read the label carefully.
For information only: the active ingredient of the Moss-out product you are talking about is zinc sulfate (a granule) and not sulfuric acid (a liquid). Yes, a diluted sulfuric acid solution is used to convert zinc carbonate to zinc sulfate to make the product (See link below). The instructions do warn the students to wear eye protection but then says the concentration of sulfuric acid used (1 mol per dm-3 (1 mol of sulfuric acid = 98 grams (about 3.5 wt. ounces) and 1 dm-3 = 100 ml or about 3.4 fl. oz.) is "an irritant". However, the label and SDS does say the Moss-out granules cause serious eye damage if they get into your eyes. As with the concentrated products above, the risk decreases substantially once you dilute them in water. I would dilute the product in water and spray with a backpack spayer. I would also recommend you wear safety glasses when handling or applying any of these products.
Since the Moss Out is highly unlikely to get into the eyes of the birds or the squirrels, I do not believe it would be harmful to them, especially once the product dries which should only take a few minutes if sprayed in the afternoon sun.
https://edu.rsc.org/download?ac=12717#:~:text=Making%20zinc%20sulfate&text=Zinc%20sulfate%20crystallises%20from%20aqueous,carbonate%20with%20dilute%20sulfuric%20acid.
The main environmental concern with Zinc Sulfate when used on roofs is that the zinc can be harmful to salmon and other fish if it gets washed off the roof into the sewar drains.
I hope this helps. Good luck.
