|WikiProject Chemistry||(Rated C-class, Mid-importance)|
Carcinogenity of carbon black
The article states: It is known to be carcinogenic and harmful to the respiratory tract if inhaled, because it contains large amounts of Polycyclic aromatic hydrocarbons.
Carbon Black MSDS shows that In 1995 IARC concluded, “There is inadequate evidence in humans for the carcinogenicity of carbon black.” Based on rat inhalation studies IARC concluded that there is, “sufficient evidence in experimental animals for the carcinogenicity of carbon black,” IARC’s overall evaluation was that, “Carbon black is possibly carcinogenic to humans (Group 2B)”. This conclusion was based on IARC’s guidelines, which require such a classification if one species exhibits carcinogenicity in two or more studies.
Columbian Chemicals MSDS is an example of an MSDS for a global supplier.
One problem with linking to such an MSDS is that it inevitably is a commercial site.
Other organisations cover the cacinogenicity of carbon black as well:
The American Conference of Governmental Industrial Hygienists (ACGIH) classifies carbon black as A4, Not Classifiable as a Human Carcinogen;
The German MAK Commission classifies carbon black as a suspect carcinogen category 3B;
The National Toxicology Program (NTP) has not listed carbon black as a carcinogen;
The Occupational Safety and Health Administration (OSHA) has not listed carbon black as a carcinogen;
The National Institute for Occupational Safety and Health (NIOSH) criteria document (1978)on carbon black recommends only carbon blacks with polycyclic aromatic hydrocarbon contamination levels greater than 0.1% (1,000 parts per million) be considered suspect carcinogens; and
The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency added “carbon black (airborne, unbound particles of respirable size)” (CAS No. 1333-86-4) to the Proposition 65 substances list on February 21, 2003. This listing, triggered by the “authoritative body” mechanism in the California Code of Regulations, was based solely on IARC's 1996 reclassification of carbon black as a Group 2B carcinogen.
Taken from carbon black a users guide, which is a publication of the International Carbon Black assosciation. The member companies of the ICBA are Cabot Corporation, Cancarb Limited, Columbian Chemicals Company, Continental Carbon Company, Degussa Corporation, Degussa Engineered Carbons, Sid Richardson Carbon Company, and The Birla Group.
Its my opinion that the ICBA publication is the best way to cite relevant saefty information in a way that doesnt directly promote one manufacturer over another.
The 'known to be carcinogenic' in the article should also be downgraded to a 'suspect' or 'possible' carcinogen, but some discussion first is merited first with others. Catwhoorg 13:47, 3 January 2007 (UTC)
Merge with Black Carbon
Strong Oppose carbon black is an engineered nano-material produced under very controlled conditions. Black carbon is impure and a catch all term. Catwhoorg 21:23, 11 January 2007 (UTC)
Black carbon has nothing to do with carbon black. Can someone take the merge suggestion header off before it starts confusing readers? 22.214.171.124 01:14, 18 January 2007 (UTC)
I agree. Please take off the merge suggestion. The use of the term carbon black for black carbon is a mistake. --Gami 00:47, 11 February 2007 (UTC)
My last edit to the main page was the removal of a commercial link that was effectively an advert. Lets keep the article encylopedic and commercial free as far as we can. Catwhoorg 13:59, 5 February 2007 (UTC)
Update "Common Uses" section to include food coloring?
I was surprised there was no mention on this page of the use of carbon black as a food coloring agent, as I linked to this page from http://en.wikipedia.org/wiki/Licorice_candy. Can someone who knows better how to use Wiki possibly add this at some point along with other foods it may be used this way in? (Sorry, no username, this is my first edit, I'll go register shortly)
Conductivity in "Surface Chemistry" section
Can someone knowledgable comment on whether conductivity in this section refers to electrical or thermal conductivity?
Needs actual photographs
The photo of the man is not useful, certainly not as the first picture. I wanted to see a sample of the material in a petri dish. The caption of the picture of the man needs to explain why he's there. --Jra (talk) 11:52, 6 May 2009 (UTC)
- I found the photo useful as an easy-to-understand illustration that carbon black is a useful industrial material. The article can say that, but it's much more effective to show it. If better images turn up we can of course use them, and move this image to lower in the article; but in the meantime it's the best image we have, so let's keep it. Eubulides (talk) 05:07, 27 May 2009 (UTC)
- I agree with Jra. The photo is supremely awesome and bad-ass but I don't see how it is relevant enough to be the lead photo. --Thomasdelbert (talk) 20:28, 17 May 2012 (UTC)
The article states 70% is used in tyres. Then later that 20% is used in rubber hoses, belts and other products, the balence used in ink. Should that read 80% (70% tyres, 10% hose belts etc, 20% ink and other) or is it to read that 70% is tyres, 20% other items, leaving 10% for ink etc. Certainly needs some calrification there i feel?
Soot, Black Carbon, Carbon black
I think that we need to more clearly differentiate between this article, soot and Black carbon. I agree with the previous consensus that this article and Black carbon probably cover different enough topics that they should remain separate. However, I think that we need a hat note that more clearly distinguishes the topics. I also think that soot may be redundant and most of should be merged to black carbon. However, some people will be looking for information on the material which lines their chimney after a fire. So soot could cover that or be a disambiguation page. Finally I think that the lead of Black carbon needs to be broadened so that it mentions other aspects of BC in the atmosphere.
In summary the new articles would be:
- Carbon black. As at present but with a lead that clearly states it is about an industrial product.
- Black carbon. Expanded to cover all aspects of particulate elemental carbon in the atmosphere.
- Soot. A disambiguation page or a page covering the deposits of elemental carbon in chimneys, flues etc.
- I notice that while the lead states that carbon black is different from soot, having more surface area and less polycyclic aromatic hydrocarbons, the "Pigment" section states that carbon black "is known by a variety of names, each of which reflects a traditional method for producing carbon black:" including "Lamp black was traditionally produced by collecting soot, also known as lampblack, from oil lamps." If carbon black is not soot, this isn't correct. Should it say something more like "... a traditional source of black carbon pigments"? Wombat140 (talk) 17:22, 14 March 2014 (UTC)
- Would it be possible to add the specification limits used to differentiate between carbon black and other forms of carbon (e.g. surface area....). When is carbon "carbon black" and when is it something else? — Preceding unsigned comment added by HeSeng (talk • contribs) 06:33, 2 May 2014 (UTC)
- The requests by HeSeng are reasonable, but probably difficult to do in practice. Surface area, for example, depends in the case of bulk materials on the heating temperature, the composition and even the structure of the biomass or fuel source, the heating atmosphere and heating time. Also, in the case of particulate matter, the surface area increases as the size of the microscopic particles decreases (very small particles like pm2.5 have very large surface area). All of these materials have some similarity chemically and often the choice of the name of the material depends on its method of generation or source, e.g,. a wood fire, a combustion chamber or furnace, automobile and diesel exhaust etc. While "black carbon" is something of a catch all term, 'carbon black' is more specific in that it is prepared by especially designed reactors for commercial purposes. Another catch all term is simply "carbonaceous material", which tends to grab everything that is a product or residue of incomplete combustion containing a significant component of refractory carbon in the form of very large networks of fused aromatic rings (PAH's). "Black carbon" often is mentioned in terms of microscopic particulate matter in the atmosphere, it also can refer to the carbonaceous material in soil, whether or not it originated from the atmosphere. Nevertheless, my comments are meant to suggest that the inclusion of some descriptive definitions of these materials would be a very useful addition to the encyclopedic commentary because it is seldom presented anywhere else. There may be a good unified discussion in the literature somewhere, but I suspect that the relevant material is scattered around many sources in disparate places depending on whether these substances are discussed in combustion, atmospheric chemistry, chemical, engineering, environmental journals, textbooks etc. It can be done. Tachyon 00:32, 22 October 2014 (UTC) — Preceding unsigned comment added by Janopus (talk • contribs)