My family has been using DeLonghi oil filled radiators for decades. They were all made in Italy. They used to produce bad fumes (it is dangerous formaldehyde) from the paint for a few days and then, it would stop. We bought three of these heaters last year. After one year of used they continue to smell horrible. We put them at max. power for three weeks 24 hours a day hoping to cure the paint and finish with fumes. No success. We can use them medium power only. If we use them maximum power the smell is horrible and irritant.
Why is the paint so different from the old Made in Italy radiators that became famous in the market for not having any smell at all? (So famous than even doctors used to recomend them to people with multiple chemical sensitivities). Because all DeLonghi oil filled radiators are now made in China with Chinese's standards paints, which are rich in Volatile Organic Compounds (VOCs). These paints were forbiden for sale by the EU, but imports of products painted with them are not forbiden. Buy other brands which costs half of the price and don't smell.
If you buy DeLonghi make sure to buy any of old remaining stock made in Italy. There are still a few stocks here and there.