Black 'dust' in cupboards

[SconesandCupcakes]

I have noticed most of the cupboards in my house have a black 'dust' in them as shown in the attached photo. This 'dust' is not like a normal dust as it needs to be scrubbed to remove it. Does anyone have any idea what this 'dust' could be and what could be causing it?

Do you have a log burner or coal fire at all?

No log burner or coal fire, although I do like to burn scented candles a few times a week.

Yes, could be log burner (and if it is, you should get it checked out a serviced by a HETAS registered professional urgently, as that is not a normal/safe amount of particulate to have floating around your air).

Have you had any work done on the house recently? Many of the brick walls in our rickety Victorian house spew black dust out of them when drilled into.

Thank you for your reply, the house is only 5 years old and I have not had any work done recently. As previously mentioned I don't have a log burner.

Where is the cupboard and what has been kept there?
Is that the back of the unit?

It's smoke from your candles.

Do you live near a main road?

Um. Might it get cold and damp in those cupboards?
How sure are you that it's not black mould?

Candles so leave this kind of residue (black soot) some of them are pretty toxic

Yes, candles, if not soy wax, can leave this soot.
I just saw a TT video the other week of an end of tenancy clean of an apartment where someone burnt a lot of candles (&obvs never cleaned) the surfaces were covered in black soot.

Thank you all for your replies @Seeline the picture is of the shelf in a cupboard which has bottled water stored in it. However it's not only this cupboard it is in all cupboards.
@adhdpunchbag yes I do live near a main road
@Fenella123 not cold or damp in any of the cupboards and I am sure it is not black mould
@ODFOx @Espanolespie @DontTouchMePlease I guess that's the end of my candle burning then! I didn't realise they could leave such a residue.

Does anyone know how I can tell for sure it's soot from the candles?

Soot sprites?

I would guess candle soot too, it especially sticks on to plastic things and can get all round the room.

@SconesandCupcakes do you trim the wicks on your candles every time, before lighting them?

Clean it off and stop burning them then you’ll know if it doesn’t come back.

I know you can rid of soot marks on walls by rubbing squashed bits of cheap white bread over them.

@FindingMyselfIn2023 yes I keep the wicks trimmed however I have recently started using Woodwick candles which you don't trim but pinch the wooden wick. I have noticed the candle does smoke a bit even when the wick is 'trimmed'
@Seeline thanks for the suggestion, I have just tried cleaning the side of a cupboard with bread, it has removed the residue well.

@IndigoBlue I am now pretty sure it is candle soot so will stop using the candles and have a good spring clean tomorrow!

@SconesandCupcakes our office is on a main road. We get lots of fine black dust in the vicinity of the windows. Maybe outside of the cupboard you are cleaning more often and don't notice it? Whereas it's settling within the cupboard?

@adhdpunchbag that's a good point, I clean the outside of the kitchen cupboards at least twice a week as they are white gloss and show every single mark! The insides are a different story maybe every few months so any dust would have time to settle.

I do light scented candles now - but the black soot that needs some serious scrubbing appeared before I had started using scented candles - and the soot has been appearing in places that candles haven't been used in.

I was only finding this black soot inside cupboards until only a few days ago when it appeared on all outside cupboards - the outside soot was a film covering the entire surface - the inside soot was in patterns and not a consistent full coverage !