Ozone in the stratosphere absorbs most of the ultraviolet radiation from the Sun. Without ozone, the Sun’s intense UV radiation would sterilize the Earth’s surface. Ozone screens all of the most energetic, UV-c, radiation, and most of the UV-b radiation.

Stratospheric ozone is considered good for humans and other life forms because it absorbs ultra- violet-B (UV-B) radiation from the Sun (see Figure Q3-1). If not absorbed, UV-B radiation would reach Earth’s surface in amounts that are harmful to a variety of life forms.

Ozone production in the troposphere is much less efficient than in the stratosphere because the intensity of ultraviolet sunlight is greatly reduced. Human activities such as fossil fuel combustion and biomass burning lead to elevated levels of tropospheric carbon monoxide, nitrogen oxides and hydrogen oxides.

Stratospheric ozone is formed naturally through the interaction of solar ultraviolet (UV) radiation with molecular oxygen (O2). The “ozone layer,” approximately 6 through 30 miles above the Earth’s surface, reduces the amount of harmful UV radiation reaching the Earth’s surface.

Air purifiers that use ultraviolet light to kill microorganisms (also known as UVGI, ultraviolet germicidal irradiation) only work against certain species. Therefore, UV-C air purifiers are not ozone-free. Not only do they produce ozone, they are not very effective in a residential setting.

The 7 Best Ozone-free Air Purifiers List:

If components or electrical elements inside your furnace are getting too hot, they may produce furnace smells similar to hot metal, burning oil, hot plastic or rubber. If you smell odors that suggest something in your furnace is overheating or burning: Shut the furnace off immediately and unplug it.

Electrical and metallic odors generally stem from excessive heat within your furnace. A smell like singed wires likely indicates an overheating metal component, while a more metallic smell may come from a damaged rubber component.

Some people can detect a metallic smell or other odors that can’t be smelled by anyone else around them because the smells aren’t real. This condition is called phantosmia, an olfactory hallucination that’s often triggered by a sinus condition. Other causes include: allergies.

Start of the Heating Season Gas Odors When your furnace sits unused during the spring and summer, it’s normal for dust, dirt, and other impurities to settle into the heating unit. When you turn on the furnace for the first time, you might notice a slight gas smell while the furnace burns off the accumulated debris.

One of the most common electrical faults announces itself with a strange fishy smell from a wall socket or switch. Generally, such a smell is caused by the arcing of electrical device.