Yep, from what I can tell it's about 10x stronger than vinegar at the same concentration, but about 1/7 the strength of citric acid (lemon juice). It's often use in wart treatments so it's not too bad in small concentrations.
However, it's flammable and can cause acid burns in the concentrations they're talking about in the article.
However, it's flammable and can cause acid burns in the concentrations they're talking about in the article.