FWIW I have had a lot of experience with vinegar over the last few years. Having to do a vinegar cleanse of our well water pump; initially bi-annually, then ~5 months, now ~ every 3-4 months. I have had fun procuring different percentages of bottled vinegar since covid-19-mare became a real logicitial issue.It is a great opportunity to do maintenance but will breathing those vinegar fumes hurt you?
Given the users admitted lung and health issues and the fact they stated they use vinegar for cleaning I'll share a semi-metaphor. For ya.... Have you ever sat next to someone or stood near someone pouring vinegar on a salad or into a bucket or bowl? Even though retail food grade is ~5% acetic acid & "cleaning vinegar" is supposed to be ~6% that really isn't much different then a really good-fresh jar of dill pickles or hot salsa. And, *Those* are when at full strength straight from the bottle. So, I'm gonna bet they are likely one to smell it as a positive freshness scent - almost invigorating.
@Caffus what say you to that assumption of mine?
Now, when you start to get into horticultural vinegar 20% and higher, yes outside & great ventilation is a must, otherwise your nose will instantly be assaulted..... When I used 30 & 40% a couple months ago it was still a surprise to me *AND I Was braced for the accidental waft* of the odor while pouring it down the funnel. I too have damaged lungs from my tour in the Navy but, it didn't "hurt" for that nanosecond of a slight wiff, it did make the nose hairs tingle....