# Soot exuded from skin for days after exposure? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [July 11, 2025, 12:30am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718 "2025-07-11T00:30:56Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [July 11, 2025, 12:30am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/1 "2025-07-11T00:30:56Z")
In theory this could be in FQ, but the question is medical, and speculative responses are welcome, so IMHO is. Here’s the deal: my friend had a house fire a few days ago and ended up with 2nd degree burns on her arm, face and shoulder. She is staying with me now and I am changing her burn dressings every day. Here is what is weird. Every day, I clean the blistered skin (gently) with cotton balls dipped in rubbing alcohol. The first day, there was some black char even though she’d had a shower after dealing with the fire. I didn’t think too much about it as she obviously wasn’t going to want to firmly scrub blistered skin. So some soot/char/whatever wasn’t too surprising. But I’ve now changed her dressings three times; her skin looks clean when the bandages are unwrapped (badly blistered, but not otherwise disturbing) but I am still getting a ton of soot-colored residue on the cotton balls. I wipe off the skin until little to no grey stuff comes off on the cotton, put on the ointment the doctor gave her, clean bandages, and do it again the next day. But the next day, lots of grey stuff comes off on the cotton again. It’s almost as if her skin “inhaled” the soot, and is gradually spitting it out, so that each day, there is a new supply of soot to be washed off (even though it can’t be seen with the naked eye; it is only visible on the cotton ball). We are both puzzled by the fact the cotton balls keep coming away sooty. Does anyone know what causes this? Could the cream, which is white and which pretty much gets absorbed into her skin every day, be turning grey as a result of interacting with her skin? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 11, 2025, 1:11am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/2 "2025-07-11T01:11:56Z")
Yes, it’s a thing. My local FD has a sauna meant for them to spend time in after coming back from a fire. From what I’ve heard, after being in there for a while, they can wipe soot off their skin. Let me see if I can find a link for the/a sauna. Here’s the first random one I found > **[Sauna Shield Firefighter Program: Saunas for all Firefighters](https://saunashield.co/blogs/news/sauna-shield-firefighter-program-saunas-for-all-firefighters)** > > Why Firefighters Deserve a Wellness Boost with Saunas Firefighters are our everyday heroes, always ready to jump into action and face danger to protect our communities. Their job is incredibly tough, both physically and emotionally. That’s why... Here’s an article about them: > **[US fire departments turning to detox saunas to fight off the cancer threat -...](https://ctif.org/news/us-fire-departments-turning-detox-saunas-fight-cancer-threat-are-they-effective)** > > Firefighters are suffering from an inordinate number of cancer deaths and some departments are hoping Chemical Detox Infrared Saunas can, at least partly, provide some relief, reports GovTech.com. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [July 11, 2025, 1:22am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/3 "2025-07-11T01:22:09Z")
I’ll just say wow. Saunas in firehouses. Never thought of that one before, but, damn, what a good idea. I bet that’s a hard one to get past the voters though. The stuff you learn on the SDMB… That one I’m going to remember. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 11, 2025, 1:25am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/4 "2025-07-11T01:25:20Z")
> [@CairoCarol](#): > > But the next day, lots of grey stuff comes off on the cotton again. It’s almost as if her skin “inhaled” the soot, and is gradually spitting it out, so that each day, there is a new supply of soot to be washed off (even though it can’t be seen with the naked eye; it is only visible on the cotton ball). There can certainly be residues that were absorbed by the partially damaged outer layers of the skin (especially volatilized polymers) but this could also be necrotic tissue or purulent exudate being expelled. You don’t mention a smell which should be apparent but if there is it definitely requires medical assessment and treatment to prevent broader infection. You mention cleaning the skin with rubbing (isopropyl) alcohol but not applying sulfadiazine or other topical antibiotic under the dressing; is this under medical direction? Stranger ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 11, 2025, 1:35am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/5 "2025-07-11T01:35:10Z")
> [@enipla](#): > > I bet that’s a hard one to get past the voters though. How much say do the voters get with respect to what the fire department wants to spend money on? I suppose indirectly by voting for/against people that have some control of the budget. IME, or at least in my jurisdiction, ‘lets give the fire department more money’ tends to over pretty well. Regardless, the one my local FD has was paid for, at least in part, with money they raised on their own. The only reason I’m even aware of them is because they did one of their fundraising events (a corn roast) at my store. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [July 11, 2025, 1:38am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/6 "2025-07-11T01:38:18Z")
Oh, I don’t know. That would be equipment and operating cost. But I wouldn’t advertise it to the public. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [July 11, 2025, 2:38am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/7 "2025-07-11T02:38:55Z")
Are you using silver sulfadiazine? This looks white, or very pale gray, and darkens with air exposure. I had to use it when I spilled some phenol crystals on the counter while compounding a skin scream, and then later leaned on the counter, not having wiped them all off. ---
**Author:** ![Q.Q.Switcheroo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/q.q.switcheroo/32/5713_2.png) [@Q.Q.Switcheroo](https://boards.straightdope.com/u/Q.Q.Switcheroo)\ **Post date:** [July 11, 2025, 2:48am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/8 "2025-07-11T02:48:57Z")
There’s a mention of this phenomenon early in Eugene O’Neill’s _The Hairy Ape_, where one of the stokers onboard a steamship refuses to wash up after a day of shoveling coal, despite his coworkers’ warning that “it’ll get under your skin.” ---
**Author:** ![Kropotkin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kropotkin/32/18045_2.png) [@Kropotkin](https://boards.straightdope.com/u/Kropotkin)\ **Post date:** [July 11, 2025, 3:00am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/9 "2025-07-11T03:00:29Z")
> [@nearwildheaven](#): > > compounding a skin scream Great typo (I hope) ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [July 11, 2025, 3:10am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/10 "2025-07-11T03:10:02Z")
Yep, a typo. IASTR that the chemical burn was painless, which was why it was as bad as it was. ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [July 11, 2025, 4:28am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/11 "2025-07-11T04:28:07Z")
> [@Stranger\_On\_A\_Train](#): > > You mention cleaning the skin with rubbing (isopropyl) alcohol but not applying sulfadiazine or other topical antibiotic under the dressing; is this under medical direction? Actually I did mention “cream”: _Could the cream, which is white and which pretty much gets absorbed into her skin every day, be turning grey as a result of interacting with her skin?_ …which is the stuff the doctor prescribed. Sorry, I wasn’t very clear. @nearwildheaven: yeah, that’s the stuff. It was prescribed for her but I guess it is available OTC as well. She was told by the doctor to be on the lookout for signs of infection but not to take an oral antibiotic unless it is needed. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [July 11, 2025, 7:27pm UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/12 "2025-07-11T19:27:00Z")
SSD is RX-only in the U.S., although there are silver compounds that are not. ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [July 11, 2025, 8:37pm UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/13 "2025-07-11T20:37:01Z")
Oh, she had a prescription and that (SSD) is what it said. She told me that she could also get over the counter stuff, maybe not realizing they were not the same. Anyway, her prescription allows 2 refills so she should be able to continue using the good stuff. Much less soot during last night’s cleaning, so maybe most of it has been expelled! ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [July 11, 2025, 9:06pm UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/14 "2025-07-11T21:06:24Z")
> [@nearwildheaven](#): > > Are you using silver sulfadiazine? This looks white, or very pale gray, and darkens with air exposure. That was my experience with silver sulfadiazine (used during one of my epic skin infections immortalized on the Dope a couple _decades_ ago now - my how time flies). It turns grey over time. But it could also be shed tissue, sure, maybe some soot… Regardless, I hope she continues to improve and avoids infection. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [July 12, 2025, 1:08am UTC](https://boards.straightdope.com/t/soot-exuded-from-skin-for-days-after-exposure/1020718/15 "2025-07-12T01:08:55Z")
A second-degree burn goes through the outer epidermal layer and involves the dermis. Within the damaged dermis, considerable inflammation and tissue remodeling are going on, mediated by macrophages/histiocytes. They are absorbing necrotic cells, bacteria and other debris that may be dark in color. Some of this will be sloughed off the blistered skin bed during healing. So it may not be soot that you’re seeing. More than you probably want to know: > **[The role of macrophages in thermal injury](https://pmc.ncbi.nlm.nih.gov/articles/PMC8918762/)** > > Macrophages, first discovered for their phagocytic ability, are a complicated and heterogeneous cell type. The unique properties of macrophages allow them to perform a vast array of functions, including phagocytosis, cytokine production, antigen ...