Re: steam cleaners, odor of wool

[Guest guest]

Barb,

I have always wondered about the odor of wool. I think I have finally figured it

out.

Sheep live with their wool for at least a season. That's a long time to go

without a bath. Whatever odors there are from the animal (sweat, bedding, etc.)

and its environemnt,the odor molecules are dispersed in the hairs.

The structure of hair is complex, but porous in the sense that water causes the

hairs to swell. If you take a hair and soak half of it in water, the damp part

almost doubles in thickness and can be stretched very readily.

Human and sheep hair are similar in that they consist of a double structure,

overlapping thin plates of cuticle on the outside that sheath rope-like lengths

of cortex fibers in the middle.

Water, dyes, etc. can actually get into the spaces between the plates (and

probably between the cortex fibers as well). So all the odorous molecules that

are stuck between the plates and cortex fibers can be redispersed when water

swells the hairs. Some of these exude from between the plates and evaporate.

A split end illustrates the hair structure. The frayed end consists of the

exposed ends of the cortex fibers. Under the microscope, these are quite pointed

and probably account for the irritation that many people experience when in

contact with wool.

The wool hairs you were cleaning up were probably present because of a problem

in the manufacture of the carpet and not necessarily because of a problem with

the wool hairs themselves.

The air quality problems caused by wool carpets and rugs is due to the

fragmentation of the hairs themselves. When the hairs break up, huge numbers of

respirale cuticle particles are aerosolized. These are fron one to 4 microns in

size. The cortex fibers also disintegrate, but the fragments are usually at

least 10 times bigger and therefore not as respirable.(I have scanning electron

micrographs of this in " My Office is Killing Me " but I will post them on my

blog.)

No amount of washing will ever stop the emission of respirable particels from

wool since it is the hairs themselves that breaking up.

The fibers in synthetic carpets are solid plastic (though some have air-filled

cores).The individual fibers do not fragment like wool.

May

May Indoor Air Investigations LLC

www.mayindoorairinvestigations/blog

>

> Jeff, I had 100% wall to wall wool carpet and it was very old, probably 40

years old, in home when I moved in. Previous owner did not have pets, and was

one of those people who removed shoes, etc, so despite its age it looked like

new, but always had this 'fuzz' on top. She called it new carpet fuzz but

carpet was far from new. When I vaccumed, vacuum bag would fill up with fibers,

yet there was plenty more to come up next time also, so it was constantly

'shedding'. It was very plush and thick. I figured that's why it always looked

new, because it was constantly shedding top layer, but perhaps fibers were so

old, they were breaking. I bought an Oreck for about a week and had to return

it because it was constantly getting clogged with carpet fibers. When I

vaccumed it, there was an odor. I thought it was my old vaccum, because carpet

looked so clean, but finally got down on hands and knees and stuck my nose in

carpet. Odor was definately coming from carpet. I removed all of it, which was

entire first floor of house.

[Guest guest]

I thought it might be horse hair mat, but actually there is horse hair mat under

carpeting upstairs also, under nylon or synthetic carpet and it doesn't smell.

In fact I am surrounded by horse hair here, as the plaster walls and ceiling are

all reinforced with horse hair I've been told and all the carpeting has horse

hair padding under them, which lines up with mold plate testing, as I picked up

a moderate amount of mucor sp, which is described as liking horse hair amoung

other things. House was built about 1938

>

> Barb,

>

> I have always wondered about the odor of wool. I think I have finally figured

it out.

>

> Sheep live with their wool for at least a season. That's a long time to go

without a bath. Whatever odors there are from the animal (sweat, bedding, etc.)

and its environemnt,the odor molecules are dispersed in the hairs.

>