Plastic smell sources - was: Window unit AC's, Ducts lined with styrofoam

[Guest guest]

At 09:25 PM 4/29/2009, you wrote:

>Does anyone know what the odor is in these filters?

I do not know.

I consider the mold release compound the most likely suspect.

Washing with water any plastic item to bring home is the best

idea. This includes computer cases, parts, mice, keyboards,

cables, anything made with manmade materials will smell

much less once it has been washed.

I do know it can likely come from these sources, but there may be more:

1) Plastic mold release compound. Similar to Pam used in the kitchen

on pans to release food from the pan surface. Most such compounds

give the " plastic smell " most people are familiar, or new car smell.

It can be washed off with just water. You can use soap as well.

It washes off within seconds, without scrubbing, it is so soluble

in water. The chemicals do vary, so rarely scrubbing or soap might

be needed. When plastic was first made, these compounds were

so deadly toxic, the maker had to wash and rinse and dry the

plastic parts before assembly, taking up square miles of warehouse

for drying in 24 hours.

Do NOT use harsh cleaners or chemicals of any sort on plastic.

See more below. Even soap can start decay processes.

Try plain water first. Do not use rain water in most cities.

Even some city tap water can contain too high of additives

and start the decay process in some plastics.

Distilled water is best, but not double distilled.

2) Some plastics release gases. Other plastics, particularly those

that are wispy, like used in washable filter, are spun, and to prevent

them from sticking to surface, or to make them spinnable, or other

reasons, a gas is added to the plastic. This gas will outgas over

time. By spinnable I mean drawing them out of a vat a thread at

a time (normal man made fiber method - nylon, polyester, etc),

and as fast as possible layering them to make the filter. Due to the

stickiness, or adhesion strength of freshly made threads, there may

have to be a delay, from 1 second to many seconds, before the

fiber can be laid down into a filter mat, or bat, or other tech term.

Spinning is typical of taking the single plastic thread, and combining

it with others to make a thread, that is then weaved into fabric, to

cut and sew together to make clothing. You will notice that some

filters have their threads sticking very strongly to each other, so

making the filter mat is done before the drawn fiber dries completely.

In many cases, like in clothing, the plastic fiber drawn out of the vat

is dry already, and can be spun immediately. Gasses can be added

to make the fiber sticky. The manufacturing methods vary a lot.

3) The glue used to hold the filter mat to the edges of the frame, if

there is any such glue in the brand model design, can outgas. As

there is so little glue used, it should go away fast enough.

4) The plastic of the frame material can be outgassing. This gas can

be of two types. Created or added during the manufacturing process

or as a result of exposure to environmental conditions (sunlight, UV)

that starts the plastic to decay, an unstoppable process, that can be

greatly accelerated by such exposures, or harsh chemicals, or even

" normal " household chemicals the maker never expected to come

into contact with their product.

5) Packaging material. The shrink wrap is heated to seal it, and

this can bound up gasses inside the package, that then permeate

the product. Upon unwrapping the product, the gas is then released,

either slowly or over time.

It's worth repeating:

I consider the mold release compound the most likely suspect.

Washing with water any plastic item to bring home is the best

idea. This includes computer cases, parts, mice, keyboards,

cables, anything made with manmade materials will smell

much less once it has been washed.