What could this be? Panicking a little

[Muchadobird]

My son (10) was just sat on sofa and about for me to come and he’s covered in some sort of yellowish foamy/sandy substance. Pic attached. Cannot figure out what this can be?!
for context, son been there for past hour, just reading. The substance is all in his hair and covering his body and clothing from head to foot. When he stood up there was a mark/outline where he’d been sat as though the substance fell on his or originated on him. He’s showered and washed his hair. I’ve throughly hoovered sofa- the substance was difficult to Hoover out in one go, took a few goes over to get it all up. There nothing on the ceiling above where he was at- it’s all smooth, clean and white. Google reverse image search and general google is unhelpful. Anyone seen this before and any clue?

I thought I had mad dandruff! It was flick from taking down my artificial Christmas tree.

Try sitting on the sofa again for a while and see what happens.

This - at 10 years old he knows but isn't saying. He's probably absentmindedly picked at something like the inside of the sofa and knows he shouldn't have.

He's not 2, he can tell you what it is himself.

this 100% he is having you on

Why are you panicking?

It’s deteriorating foam. If you take the cover off you’ll see the stockingette will have moved or deteriorated abd the foam will then be accessible through the zip or a hole or something.

Your son knows what it is, but is too scared to say you, looks like they have pulled something apart. Hope you get to the bottom of what it is.

That’s the foam kind of material found inside the stress / squishy toys. Like these:

I'm afraid I'm another one who thinks your son knows and just doesn't want to say. Unless he is very ND, a 10 year old, even engrossed in a book would feel a gust of wind from an open door and / or feel things landing on him.

Have you kept a sample of it?

what is a ranch slider?

I think it's the NZ equivalent of a patio door.

I read it as ranch spider, what with the NZ location. 😜

OP it looks like squishy toy innards as others have said.

I remember having to make up stuff (sometimes not even consciously!) when my mum asked me since she always seemed so upset (& in her case, angry) with me. Often the made up version was more palatable for my mother… You sound (& say) you’re panicking a little, so I wonder if he’s making it up that he’s not sure.

Maybe the clothes went in the wash with a squishy toy or similar that burst and he’s not noticed when he changed his clothes

This is like some kind of parallel universe

I was gonna say this! As my daughter suddenly had foamy stuff all over her, turns out she had burst her squishy toy!

Sliding glass doors!

not what I'd personally call a patio door, which, to me, is hinged.

You're confusing NZ & Australia. Nz spiders are just normal like UK spiders

Any updates?

Did you see him during the hour he was sat there reading, can you be 100% confident he hasn't been in the upside-down?

Only upside down.

Ectoplasm!! 👻

Looks like sofa or cushion stuffing

It does looks like foam from a sofa, or something. I'm with those who say your son knows but is worried he'll get in trouble if he tells you.