Coldair - I have a Vulcan 1000W oil-filled heater that is probably 15 yrs old. It was sold by Southcorp Heating & Cooling who are based in South Australia; but the heater was made in Portugal.
Just recently I noticed an unpleasant odour being emitted from the heater. SWMBO, who is particularly sensitive to unpleasant odours complained about the smell permeating the rest of the house (I use in the home office).
An inspection shows dark staining around the vents and controls on the end of the heater. I believe it is probably leaking some oil when hot - although there's no sign of actual oiliness. I usually run it for 2-3 hrs of an evening, but not every evening.
I'm going to scrap it, they aren't expensive to purchase; and I believe the fumes with the unpleasant odour are probably mildly toxic - but I cannot find anyone who can verify that, or any research having been done in that area.
I've never felt unwell from the fumes, nor do I believe I've suffered any ill-effects from them - but I'm happy to scrap a domestic consumer device this age, because we all know they're aren't built to last any more, anyway.