Well, proteins aren't alive, any more than any other polymers are, for
just about any definition of alive you can come up with.

Why should it fall apart?  It has structural strength.  I've got wool
blankets that are decades old.  They aren't alive, and they haven't
fallen apart.  Wool is keratin.  Cellulose is another natural polymer
with substantial structural strength.  Linen fabric and wooden objects
centuries and even millennia old are well-known.  Ditto silk, another
protein fiber.

Melanin pigment is pretty stable too, although it does deteriorate
under UV light, so hair gets a little bleached by sun exposure. Oil
will spread down other kinds of fiber too, by simple physics.

Hair cells, like skin cells, die and dry out as they are displaced from
the follicle or basal layer by new cells.  Hair cells are actually
modified skin cells, as are cells of feathers.  In these tissues, a lot of
keratin is produced, and the cells are all crosslinked with structures
called desmosomes that sort of spot weld the cells together at many
places on the surface.

There's lots of stuff in the world that doesn't fall apart even though
it's not alive, even if it was once part of a living thing.  Of course,
it can't repair or renew itself once it's dead, but there's no reason
it can't last for some time before deteriorating significantly, as long
as it's dry or otherwise protected from conditions that encourage rot.

I have been googling this at length regarding the so called dead hair cells
(and keratin) that make up your hair.  Very confusing and could not pin down
whether fibrous protein (such as keratin) is "alive" or "dead", or maybe a
little of each.  If your hair above the follicle is dead than why doesn't it
just break off, or is it the "dead" keratin that continues to hold it
together until it grows "up to" several feet in length.  Plus, if it is
totally dead, than how does it hold its color, and allow oils to be spread
down its length (ie greasy hair if you don't wash it).  These are just a
couple points.

I doesn't sound like hair is "totally" dead above the skin level.  I
understand it has no nerve cells or you would be in pain when getting a hair
cut.  What is really going on with the dead cell stuff, and is fibrous
protein alive, or dead, or what.  Please shed a little light on this if you
will.

Thanks...Pete

Jeff writes:

1) Please use plain text, not HTML. HTML is harder for some people to read
because they don't have the proper font, harder for blind people (for text
to voice software) and wastes bandwidth.

2) keratin is a protein. It is not alive. So hair is dead.

3) Hair is made of strong proteins (keratin) that don't just break off.

4) Hair is able to hold water and oil just like clothing. In fact, wool is
just keratin from another animal (baa baa).