Carbon Black

Full Profile

General Information

Carbon black is essentially composed of elemental carbon.^[2] Its fundamental units are aggregated carbon particles (chains) with large surface areas, which are used to absorb fluids and reinforce materials.^[3] Various types of carbon black are manufactured in powder or pellet form; all are insoluble in water and organic solvents, but vary in particle size, surface area per unit mass, and aggregate size.^[2,3] Other names for carbon black include “acetylene black”, “channel black”, “furnace black”, “lampblack” or “thermal black”. There are numerous other synonyms and product names; see HSDB for more information.^[4]

Carbon black has been classified by IARC as a group 2B carcinogen, possibly carcinogenic to humans, with evidence from animal inhalation studies showing significant increases in the incidence of benign and malignant lung tumours.^[2] In humans, excess risk of lung cancer was found in some epidemiological studies, however findings of a dose-response relationship between lung cancer and carbon black exposure were inconclusive.^[2] Isolated epidemiological results indicate potential excess risks of urinary, bladder, kidney, stomach and esophageal cancers following exposure to carbon black.^[2]

Acute respiratory effects following carbon black exposure include cough, sputum production, and shortness of breath; potential chronic effects include reduced lung function, emphysema, chronic bronchitis and fibrosis.^[13] Carbon black “tattoos” may result when carbon black particles become embedded in the skin, causing discolouration.^[13]

Carbon black has been ranked by CAREX Canada as Group A (immediate high priority) for both occupational and environmental settings. Prioritization was based on the carcinogenicity and other toxic properties of the substance, the prevalence of exposure in Canada, and the feasibility of assessing exposure.

Regulations and Guidelines

Occupational Exposure Limits (OEL)

Canadian Jurisdictions	OEL (mg/m3)
Canada Labour Code	3.5
BC, AB, MB, ON, QC, NL, PE, NS, NB	3.5
SK	3.5 7 [stel]
Other Jurisdictions	OEL (mg/m3)
ACGIH 2010 TLV	3.5

Canadian Environmental Guidelines

Canadian Agencies/Organizations

Agency	Designation/Position	Year
Health Canada	DSL – high priority substance with greatest potential for exposure	2006[7]
CMP Challenge	Batch 12	1999[9]
Environment Canada	Vinyl chloride release regulations: limit the release of vinyl chloride from vinyl chloride plants and polyvinyl chloride plants	2009[12]

Carbon black is not included in other environmental regulation guidelines.^[8]

Main Uses

About 90% of produced carbon black is used to reinforce rubber products, predominately tires; 9% is used as a pigment in inks and paints.^[2,10] The remaining 1% is used in various other applications including coatings, paper and plastics.^[2,10]

Canadian Production & Trade

Canada is a net exporter of carbon black; the majority of export is to the US.^[11] In 2004 there were 4 facilities producing carbon black (2 in Ontario, 2 in Alberta) with a total capacity of 293,000 tonnes.^[11] Most of the carbon black produced in Canada is furnace black.^[11]

Production and Trade

Activity	Quantity	Year
Canadian Production	273,000 t	2005*[11]
Domestic Consumption	235,000 t	2005*[11]
Export
Mainly to the US	112,000 t of ‘carbon: carbon black and other forms of carbon’	2009[12]
Import
Mainly from the US	51,000 t of ‘carbon: carbon black and other forms of carbon’	2009[12]

Occupational Exposures

Inhalation is the most important route of occupational exposure to carbon black.^[12,16] The highest levels of exposure occur in occupations involved in the production of carbon black, particularly packers and site cleaners.^[2] Occupational exposure may also occur in the rubber industry, mainly in compounding and mixing areas, and in other user industries such as paint and printing.^[2]

Environmental Exposures

As of 2009, Canadian monitoring data for the presence of carbon black in air, water, soil or sediment could not be located.^[17] Carbon black is emitted into the air by carbon black manufacturers, but modern production plants generally use filters to reduce emissions to under 50 mg/m³.^[3] Since carbon black particles are bound within consumer product materials, exposure from the use of these products is also likely to be limited.^[2]

Carbon black release is not reportable to the National Pollutant Release Inventory (NPRI) in Canada.^[18] A search of a consumer product database yielded the following results:

US Household Products Database

NPRI 2010[16]
Search term: 'carbon black'
Category	Quantity	Product type
Total	>100	Auto paints and primers, gasket makers, shoe polish, printer toners and inks, wood finishers, and urethane patch kits.

Sources

1. Wikimedia Commons photo for carbon black
2. IARC (2010) Monograph Volume 93: Carbon Black, Titanium Dioxide, and Talc
3. IARC (1996) Monograph Volume 65: Printing Processes and Printing Inks, Carbon Black and Some Nitro Compounds
4. US National Library of Medicine (2010) Hazardous Substances Data Bank entry for Carbon Black (Search term: ‘carbon black’)
5. Health Canada (2010) Guidelines for Canadian Drinking Water
6. Health Canada (1987) Exposure Guidelines for Residential Indoor Air Quality
7. Health Canada (2006) Categorization of the Domestic Substances List under CEPA
8. Environment Canada (2010) Toxic Substances List – CEPA Schedule 1
9. Government of Canada (2008) Chemicals Management Plan – List of all Challenge Substances
10. International Carbon Black Association (2006) What is Carbon Black
11. Camford Information Services (2004) Product Profiles: Carbon Black
12. TradeMap (2010) Canadian international trade (free subscription required)
13. CCOHS (1997) Health Effects of Carbon Black
14. Environment Canada (2009) Substance Profile for the Challenge: Carbon Black
15. Environment Canada (2009) The National Pollutant Release Inventory
16. US Department of Health and Human Services (2010) Household Products Database