Talk:Formaldehyde

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There should be a section on Paraformaldehyde.

there are over 3000 citation in pubmed.

It is a essential tool in histological analysis of tissues with over 3000 citation in pubmed.


4: Augusteyn RC, Vrensen G, Willekens B.

The effect of paraformaldehyde fixation and PBS storage on the water content of the human lens.

Mol Vis. 2008 Jan 17;14:90-4.

14: Lyck L, Dalmau I, Chemnitz J, Finsen B, Schrøder HD.

Immunohistochemical Markers for Quantitative Studies of Neurons and Glia in Human Neocortex.

J Histochem Cytochem. 2007 Nov 12;

Contents

[edit] Methanal vs Methanol and preferred name

The 'formalin' page is redirected to this page. Actually 'formalin' is not the same as formaldehyde. Formalin is a saturated solution of formaldehyde, water, and typically another agent, most commonly methanol. A new page should be created for formalin and the use of the word 'formalin' in this article as a substitute for formaldehyde needs to be eliminated. Cheetah58 (talk) 14:29, 14 April 2008 (UTC)

It's Methanal: someone wrongly "corrected" this to "methanol". I've changed it back. Note that methanal is the same as formaldehyde, but that methanal is not the same as methanol.

  • Also, before any IUPAC pedants step in, the preferred name is formaldehyde, as in the article, although methanal is also correct. Physchim62 20:53, 29 May 2005 (UTC)
  • Isn't the IUPAC name 'methanal' though? So under 'IUPAC Name' it should say 'methanal' not 'formaldehyde'

[edit] Formula Writing

HCHO seems like an odd way to write the formula. Its structure is more like:

H    (H2CO)
 \
  C==O
 /
H

-Unknown

Regarding your comment that "HCHO seems like an odd way to write the formula", actually it is not because this way of writing the formula highlights it's functional group as an aldehyde R-CHO where R in this case is only hydrogen (H) making formaldehyde the simplest form of this functional group. -Unknown

[edit] Picture

Can someone find or make a better picture? Current one does not show the 'C' and while it may be obvious to a chemist might mislead or confuse some people. -Unknown

I can draw that out using my Chemsketch and convert the file into JPEG format, but how do i attach the file onto this page? -Unknown

[edit] Reaction products: paraformaldehyde + nitric acid

Can anyone help to determine the rection products of a reaction using paraformaldehyde (solid) and concentrated nitric acid? Thanks. -Unknown

If you insist that it is paraformaldehyde that reacts, then there is no way of completing the above reaction for you because paraformaldehyde itself is a polymer (oligomer). Usually acid is added to paraform when mixing it with formalin or water in an attempt to make a solution of formalin. -Unknown
As the de-/polymerization of formaldehyde is effectively catalyzed by acids, I would expect cleavage of paraformaldehyde to monomeric formaldehyde wich would then be oxidized to formic acid. The reaction may proceed vigorously. (just a guess)

[edit] Formaldehyde in beer

Is Formaldehyde used in beer? Heard that some Japanese beer contained Formaldehyde.....true? (posted to article by 220.108.208.252, moved here 04:27, 2 Jan 2005 (UTC))

Watched a movie called 'Good morning Vietnam' (Robin Williams) last night. Was shocked that the Vietnamese beer contained formaldehyde. But not too sure if that's true. -Unknown
I would not be suprised to find that beer contained small amounts of formaldehyde. Fermentation has a lot of minor byproducts. Shimmin 14:32, Feb 16, 2005 (UTC)
Couldn't find anything about formaldehyde in Beer Lao after googling around. should we remove that sentence? —Preceding unsigned comment added by 121.6.200.62 (talk) 12:28, 15 July 2007

[edit] Formaldehyde kills most bacteria?

I'm not quite sure about this I thought it killed everything spores inculded. We use it to sterilze the HEPT filters. http://encarta.msn.com/encyclopedia_761578019/Formaldehyde.html

[edit] Boiling Point Temperature?

Entry says that the boiling point is -21 celsius, or 262 Kelvin; this is wrong. Minus 21 celsius is 252 Kelvin, 262 Kelvin is -11 Celsius. Which of these is correct? DS 16:24, 14 August 2005 (UTC)

Uppercase degrees "Celsius", lowercase "kelvins". -Unknown
Don't ovrlook the fact that the infobox value is different from either of those numbers: -19.0 °C (254.1 K) (and I wouldn't bet on there being a significant zero in that number). Gene Nygaard 18:25, 14 August 2005 (UTC)
253.85±0.2 K according to NIST, which converts to -19.3±0.2 °C. I shall change the infobox and text accordingly. Physchim62 18:34, 14 August 2005 (UTC)

[edit] Organic molecules in space

According to Isaac Asimov's Guide to Science, formaldehyde is also found in interstellar space. -Unknown

[edit] Is it a Carcinogen?

While this might be true, I'd like to see a source on it. You can't just label something a carcinogen after all, I think we need an explanation of how it causes cancer. As far as I know, that involves damaging DNA, since damaged DNA is what leads to cancer. I'm not sure how formaldehyde would do that. Tyciol 05:30, 19 February 2006 (UTC)

Carcinogenicity is usually measured by exposure studies on experimental animals and (where applicable) on humans, rather than by a purely mechanistic approach. At Wikipedia, we usually rely on the monographs published by the IARC, which are internationally recognised: the IARC classes formaldehyde as a group 1 carcinogen, the highest level. Details of the studies can be found in the links I have added at the bottom of the article. Physchim62 (talk) 07:16, 19 February 2006 (UTC)
Thanks, now I know where to look on information. I think case studies and evidence like you've said, are very important. Even so, I think it's more sufficient to at least have an operating theory on how the carcinogen functions in increasing cancer risk, because then countermeasures can be invented. The reason I'm drawn to this article is my investigation into Aspartame, and the metabolism-produced formaldehyde and how they might differ in health risks. Tyciol 16:59, 20 February 2006 (UTC)
To hazard a guess, formaldehyde would react with the free amino groups on DNA bases producing Schiff bases, which could effectively be reduced to methylated bases. It also apparently promotes DNA-protein cross linking, possibly by a similar mechanism. Both of these would interfere with DNA transcription and hence be carcinogenic. As for metabolic formaldehyde, you would need to look at where it is produced; I would image that aspartame is mostly metabolized in the liver, so the formaldehyde would be rapidly oxidized out of harm's way. The three cancers which are associated with formaldehyde exposure are nasopharyngeal cancer, leukemia and sinonasal cancer, characteristic of cell damage at or near the site of exposure (by inhalation). Physchim62 (talk) 18:45, 20 February 2006 (UTC)
Cool thanks. I'm going to study these terms so I can get more familiar with methylation and stuff. That info about aspartame being oxidized is good though, now I can get some diet pop... because sugar's a cancer contributer too in excess, also crosslinking proteins and stuff. Tyciol 03:53, 21 February 2006 (UTC)

The statement citing "studies" that show no evidence of carcinogenicity at low levels still needs a citation. Cognisant that carcinogenesis is a stochastic process, I'm not sure if the statement is defendable. I added a reference to the IARC determination of sufficient evidence, and corrected the dose threshold for non-stochastic effects (irritation) citing Health Canada and USEPA.Vdaliessio 18:40, 5 March 2007 (UTC)

I am new at this so I hope I am doing this correctly. May I offer two items for consideration? First, the url for the June 2004 IARC news release is http://www.iarc.fr/ENG/Press_Releases/archives/pr153a.html. The release is entitled "IARC CLASSIFIES FORMALDEHYDE AS CARCINOGENIC TO HUMANS." The US National Toxicology Program (part of HHS) is the keeper of the official US carcinogens list. Based on a nomination from NIEHS, NTP will consider codifying for the US the IARC 2004 determination, i.e., to move formaldehyde to known human carcinogen status. The NTP url is http://ntp.niehs.nih.gov/index.cfm?objectid=7BE524E1-F1F6-975E-76BB0ABD6CC9076A. Second, the article states that it needs a footnote for the statement that formaldehyde is a common indoor air pollutant. As one authority, I would offer the 2005 California EPA Air Resources Board Report entitled "Indoor Air Pollution in California." The url for the Report is http://www.arb.ca.gov/research/indoor/ab1173/finalreport.htm and the section on formaldehyde begins on page Report page 65. A point of full disclosure - I am with Johns Manville, which in 2002 switched its entire line of fiber glass building insulation to no added formaldehyde. We thought it was a smart thing to do and it has been well recieved. So, formaldehyde health issues are important to us. Thanks. bruceray-jm; 9-11-07 —Preceding unsigned comment added by Bruceray-jm (talk • contribs) 03:02, 12 September 2007 (UTC)

[edit] Oxide Catalyst

It is unclear which iron oxide is used (does it matter?) and whether the molybdenum and vanadium are present as the metal or as oxides. Does anyone know more?

[edit] Allergen?

I strongly doubt that there is a formaldehyde allergy, as an allergy is an IgE-dependent response which can hardly be caused by a small molecule. There might well be a formaldehyde hypersensitivity. And we obviously need better sources for that (i.e. from the scientific literature). Icek 12:38, 6 July 2007 (UTC)

[edit] European Ban

I added that Europe was banning formaldehyde on the 22nd of Semptember, 2007. The section 'Embalming' now needs cleaning up (it no longer makes sense the way it is phrased). Can somebody help with this? Dancanm 18:39, 9 July 2007 (UTC)

I have tried to do this by moving a passage around. I have deleted the following passage :

'The European Union is considering a complete ban on formaldehyde usage (including embalming), subject to a review of List 4B of the Technical Annex to the Report from the Commission to the European Parliament and the Council on the Evaluation of the Active Substances of Plant Protection Products by the European Commission Services'

I hope it makes a bit more sense now. Also see my comment in the 'Embalming' section below.--Godfinger 19:33, 22 August 2007 (UTC)

[edit] Formaldehyde in marijuana?

Far be it from me to question whoever wrote this section, but I hardly think formaldehyde is frequently found in marijuana.

Marijuana, like most leafy plant materials is rich in sugars and starches, when these are combusted at less than stoichiometrically optimum air / fuel ratios, the partial combustion products likely contain aldehydes including formaldehyde. I assume this is what the section refers to. Same is true for tobacco cigarettes and others.Vdaliessio (talk) 18:57, 7 March 2008 (UTC)


I'm pretty sure this is referring to a substance being added to marijuana. That Substance being Phencyclidine or PCP. The drug is often called "Embalming Fluid". (talk) 14:51, 25 March 2008 (UTC)

[edit] Embalming

I added a reference that I think supports the following statement that was previously uncited :

Countries with a strong tradition of embalming corpses, such as Ireland and other colder weather countries, have raised concerns.[7]

The link leads to a Wall Street Journal article but the full article is only available to subscribers of which I am not, so I was not able to check if it actually supports the statement but it looks like it probably does from the first paragraph. It would be a good idea to check it to see if the reference is accurate-so if anyone is a subscriber could they check it and see if it is suitable.--Godfinger 19:06, 22 August 2007 (UTC)