Does TSP Outgas Toxic Fumes

October 20, 2015, by Debra Lynn Dadd

Question from TA

Hi Debra,

Hi Debra, I'm confused about TSP. I was looking around your site for info about it because I see it's an ingredient in Concrobium Mold Control, which I was looking into using on a shower. The product is said to be non-toxic, and I see it listed as a recommended product on your site. www.concrobium.com/wp-content/uploads/2012/05/Concrobium-Mold-Control-SDS-May-2015.pdf

I see this on the EWG database: www.ewg.org/guides/substances/6194

Do I understand correctly from the info on that EWG link that TSP is not safe as a food additive but it's okay as a cleaner? The link you gave above seems to indicate it's not safe as a cleaner either (it's caustic). So I'm not sure what to make of it at this point. Also, the EWG link shows an "F" rating for TSP - though it seems to be saying that mainly for food (I think?), and the database is about household cleaners! Here is some info from Concrobium's site:

"TSP is trisodium phosphate, a mixture of soda ash and phosphoric acid. TSP is toxic if swallowed, but it can be used on many jobs, such as cleaning drains or removing old paint, that would normally require much more caustic and poisonous chemicals, and it does not create any fumes."
from: www.concrobium.com/wp-content/uploads/2012/07/Envirosense-Fact-Sheet-Non-Toxic-Products.pdf

I need to be able to take care of this icky shower safely and without lots of physical exertion - lots of scrubbing and inhaling the mildew, etc, isn't going to work for me, and I don't want to be using something toxic (for myself, as I'm sensitive, and I don't want my child breathing in harmful fumes either). Can you make sense of these various sources of information and tell me if the product containing TSP is, in fact, safe to use? Also, it seems that part of the concern is due to the phosphates which can be an environmental issue. Any ideas about this?

Hmm...I just went back to EWG and searched for Concrobium (instead of just searching for trisodium phosphate as I did earlier), and found this: www.ewg.org/guides/cleaners/2287-ConcrobiumMoldControl

There they give TSP a "C" rating, and the product an "A" rating. Perhaps the product is safe enough after all?

I also see that Concrobium has a Mold Stain Eraser product, but I'm having trouble finding the MSDS for that one, to check the ingredients.

Debra's Answer

These are all good questions. It’s easy to be confused about this, so I’m glad you asked.

When I first started looking at the toxicity of products, the main thing I was looking at was did it emit toxic fumes.

I consider TSP to be a “safe” cleaner because it’s not toxic.

But there are other ways that substances can be harmful. And one of them is that it can be caustic, which means it can burn through your skin. It won’t cause cancer, or damage your cells, but it can burn through your skin.

I took a look at the EWG page you referenced and yes, you are understanding correctly. The F rating applies to TSP used as a food additive.

But as a cleaner, it’s not going in your body, it has no fumes, and the only way it would be harmful would be if it splashed on your skin or in your eyes. So you could use it with goggles and gloves and be perfectly safe.

Another thing that makes a difference in terms of harm is the dilution. It may be that in corcrobium the amount is so small that it presents no danger. Yet it needs to be in the ingredient list.

There would be no fumes at all from TSP. I use this product myself in my shower.

I have no concerns about it.