Does anyone know what this actually means?

[Jem]

I saw this post on a friends facebook account. I laughed my butt off...but I truly have no idea what this warning is for. The post as funny as it is, is quite accurate!

 

[Willowy]

Oh I saw this somewhere! It's a warning for a chemical that literally melts your lungs, but also the picture is degraded so it looks worse than it did originally. Let me see if I can find it. . .

Ok, you can buy t-shirts of that sign labeled "explosive decompression warning" so I guess it wasn't for a chemical. Still haven't found the original sign.

Haha, this is going to send me down a rabbit hole. Here's the sign with a bit of text visible, and you can see it mentions fumes, so, yes, despite the t-shirt company's labels, it is about fumes.

And this is the current welding fume safety sign, and that thing at the bottom left is probably a stick welder, so almost certainly a welding fume warning sign, overly pixellated by the black-and-white newsprint. And, yes, some welding fumes will melt your lungs.

There's a whole Reddit thread about it, some welder dude explains it:

 

[Willowy]

And now that I know they exist, I kinda want an explodey-lungs t-shirt!