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Toxicity Answered

Does anyone know how toxic the foam inside a refrigerator door is (Urethan foam?)? Is there any danger in coming into contact with it? All I can seem to find online is long-term effect of the foam on the environment (which are apparently very bad). In short, should I cover up the back of the door and never think about again, or can I remove it from the door with a chisel without much worry? I want to remove the foam because it looks a little moldy on the top. Any suggestions? I'm making a magnetic bulletin board for my wall in case you were wondering. thanks, Randy


I did an msds search myself and found disturbing information:

When i was a kid urethane was, so i've been told, made as a byproduct of ranching--a way to use urea. Urethane pillows were popular for their softness and affordability, but hinted to the nose about their origin when damp or in humid weather. Rather unnerving to think of the boomer babies and their parents sleeping on urethane pillows, given what follows.

What follows is a partial quote from physchem.ox.ac.uk/... :

General (included in this comment so we might recognize synonyms and have a little techie perspective -- ccddkkuu)

Synonyms: ethyl carbamate, ethyl urethane, carbamic acid ethyl ester, O-ethylurethane, ethyl aminoformate, leucethanem, leucethane, leucothane, pracarbamine, uretan, urethan
Molecular formula: C3H7NO2
CAS No: 51-79-6
EINECS No: 200-123-1
Annex I Index No: 607-149-00-6

Physical data

Appearance: white crystalline powder
Melting point: 48 C
Boiling point: 182 - 184 C
Vapour density: 3.07 g/l
Vapour pressure:
Density (g cm-3): 1.1
Flash point: 92 C (closed cup)
Explosion limits:
Autoignition temperature:
Water solubility: substantial


Stable. Incompatible with strong acids, strong bases, strong oxidizing agents.


Possible carcinogen; IARC carcinogen rating 2B. Harmful if swallowed.

Toxicity data
(The meaning of any toxicological abbreviations which appear in this section is given here.)
(LD50 is discussed in another comment on this page. Note that this means immediate deaths, not later due to cancer. -- ccddkkuu)
ORL-RAT LD50 1809 mg kg-1
ORL-MUS LD50 2500 mg kg-1
SCU-MUS LD50 1750 mg kg-1
IMS-RAT LD50 1400 mg kg-1
ORL-CKN LD50 2188 mg kg-1
IVN-GPG LDLO 800 mg kg-1

Risk phrases: R45. ( R45 = May cause cancer. -- ccddkkuu)

Transport information Non-hazardous for air, sea and road freight.

Personal protection

Safety glasses, gloves, good ventilation. Handle as a possible carcinogen. (emphasis added to keep randofo making far future instructables -- ccddkkuu)

Don't confuse properties of the monomer with properties of the polymers. A lot of the monomers used to create common plastics are pretty nasty before polymerization (Vinyl Chloride...)

Good point, Westfw. Thanks. That could easily pass as a subtle fine point, which it is not.

You have inspired an afternoon of fresh homework today on this and related topics.

Forums such as this, with a co-operative and supportive spirit, are inspiration also, in favor of believing in human social potential. Never mind how the media depicts us.

While i'm on that soapbox, thank you all for being part of this community.

. What you have shown is not that bad - it can be shipped as non-hazardous and the PPE listed is the lowest level. The PPE standards are set for ppl that work with the stuff frequently and if it was that bad, it would call for at least a respirator/filter. . I wouldn't go around eating the stuff, but I wouldn't force myself to throw up if I swallowed a small piece either. . As others have pointed out, the products of incomplete combustion (PICs) are liable to be dangerous, but the stuff in a 'frig probably has flame retardants added. . Trying to remove the stuff will most probably cause more problems than leaving it alone. In particular, inhalation hazards. . A dilute bleach solution may help get rid of the mold.

. PS: Keep in mind that I am not an expert. When in doubt, play it safe.

Burning, it's very dangerous, for removal a comfort/dust mask is sufficient. A quick msds search shows the LD50 is > 5000 mg/kg body weight (rats)

Your punctuation confuses me.... so bear with me. I take it that I shouldn't set it on fire. However, it is safe to remove with a dust mask?

The term LD50 is the "Lethal Dose for 50 percent" of the tested population. So in this case, five grams of the test substance per kilogram of rats was enough to kill half the rats tested.

Sorry long day ;-) Yes it's safe to remove using just a dust mask.


11 years ago

A softer form of urethane foam is widely used in furniture cushions, so it's not very harmful. As TUA says, don't burn it or try to cut it with hot-wires; nasty fumes (cyanide?)