Summary of EPA’s Current Assessments of Health and 

Environmental Effects of Carbon Nanotubes 

U.S. Environmental Protection Agency 

May 2010 

Docket Identification Number 

 EPA-HQ-OPPT-2008-0252 
Summary of EPA’s Current Assessments of Health and Environmental 

 Effects of Carbon Nanotubes

Human Health Effects Summary for Carbon Nanotubes:

Absorption is expected to be poor via all routes for the carbon nanotubes based on test data for 

chemicals with similar molecular structures and chemicals with similar physical/chemical 

properties. Data on other analogous substances indicate the potential for generation of increased 

amounts of respirable or absorbable particles during processing and use of nanoscale materials. 

Much more evaluation is needed to determine the toxicity of nanoscale materials for all routes of 

exposure. There are concerns for lung effects, based on the EPA Respirable, Poorly Soluble 

Particulates chemical category. See www.epa.gov/oppt/newchems/pubs/cat02.htm#Respirable. 

Based on test data for analogous chemicals including other carbon nanotubes, there are concerns 

for pulmonary toxicity, fibrosis, carcinogenicity, mutagenicity, and immunotoxicity of the PMN 

substance, There are also data suggesting that pulmonary deposition of some nanoscale 

materials, including carbon nano[tubes] in the agglomerated form, may induce cardiovascular 

toxicity when these nanoscale materials are inhaled. The major health concerns are for potential 

pulmonary toxicity, fibrosis and cancer to workers exposed via inhalation. Based on the 

uncertainty of the characterization and exposure of nanoscale materials in general, there may be 

additional potential for translocation across the dermis and effects on target organs. 

Bonner, J.C. et al., (2009). Inhaled multi-walled carbon nanotubes stimulate a pleural 

inflammatory response in the lung of mice. SOT Abst. NO. 2205. 

Holker V, et al., (2005). Cardiovascular responses in unrestrained WKY rats to inhaled ultrafine 

carbon particles. Inhal. Toxicol. 17:29-42. 

Hubbs, A. et al., (2009). Persistent pulmonary inflammation, airway mucousmetaplasia and 

migration of multi-walled carbon nanotubes from the lung after subchronic exposure. SOT abst. 

No. 2193. 

Jia, G. et al., (2005). Cytotoxicity of carbon nanomaterials: Single-wall nanotube, multi-wall 

nanotube, and fullerene. Environ. Sci. & Technol. 39(5):1378-1383. 

K. Donaldson, R. Aitken, L. Tran, V. Stone, R. Duffin, G. Forrest, and A. Alexander, (2006). 

Carbon nanotubes: A review of their properties in relation to pulmonary toxicology and 

workplace safety, Toxicol. Sci., 92, 5-22. 

Lam, et al., (2004). Pulmonary Toxicity of Single-Walled Carbon Nanotubes in Mice 7 and 90 

Days after Intratracheal Instillation. Toxicol. Sci. 77:126-134. 

Landsiedel et al., (2009). Carbon nanotubes tested in 5- and 90-day inhalation studies in rats. 

SOT Abst. No. 2194. 

Muller, J. et al., (2005). Respiratory toxicity of multi-wall carbon nanotubes. Toxicol Apply. 

Pharmacol. 207: 221-231. 

Muller, J. et al., (2008). Structural defects play a major role in the acute lung toxicity of 

mutiwalled carbon nanotubes: Toxicological aspects. Chem. Res. Toxicol. 21:1698-1750.
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Nemmar A. et al., (2003). Size effect of intratracheally instilled particles on pulmonary 

inflammation and vascular thrombosis. Toxicol. Appl. Pharmacol. 186:38-45. 

Nurkiewicz, et al., (2008). Nanoparticle inhalation augments particle-dependent systemic 

microvascular dysfunction. Particle and Fibre Toxicology 5,1. Available from: 

http://www.particleandfibretoxicology.com/content/5/1/1. 

Poland, C.A., R.Duffin, I. Kinloch, A. Maynard, W.A.H. Wallace, A. Seaton, V. Stone, S. 

Brown, W. MacNee, and K. Donaldson, (2008). Carbon nanotubes introduced into the abdominal 

cavity of mice show asbestos-like pathogenicity in a pilot study. Nature Nanotechnology 3, 423 – 

428. 

Porter et al., (2009). Pulmonary toxicity in inhaled multi-walled carbon nanotubes. SOT Abst. 

No. 2195. 

Sayes, C.M. et al., (2005). Functionalization density dependence of single-walled carbon 

nanotubes cytotoxicity in vitro. Toxicol. Lett. 162:135-142. 

Schladweier, et al., (2009). Single-walled carbon nanotubes induced pulmonary and vascular 

response following intratracheal instillation. SOT Abst. No. 2203. 

Shvedova A.A., et al., (2005). Unusual Inflammatory and Fibrogenic Pulmonary Responses to 

Single Walled Carbon Nanotubes in Mice. Am. J. Physiol. Lung Cell Mol. Physiol.: 10.1152-

1184. 

Warheit D.B. et al., (2004). Comparative Pulmonary Toxicity Assessment of Single-wall Carbon 

Nanotubes in Rats. Toxicological Sciences 77:117-125. 

Wolfarth, M.G. et al., (2009). Pulmonary toxicity of multi-walled carbon nanotubes. SOT Abst. 

No. 2196. 
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Environmental Effects Summary for Carbon Nanotubes:

Toxicity from carbon nanotubes exposure has been reported in many aquatic species at 

concentrations much higher than any estimated solubility limits. Even though CNTs are not 

appreciably water soluble as manufactured, aqueous suspensions can be easily made through 

reaction with strong acids, ozone, or dispersing agents. Recent laboratory research shows that 

carbon nanotubes combine with dissolved organic matter to form stable aqueous suspensions. 

No studies on carbon nanotubes are available in which a broad range of production methods, 

sources, purification, functionalization, etc. were investigated. EPA expects that some fraction 

of the carbon nanotubes, if released into the environment, will eventually become suspended in 

water. Sublethal effects have been noted for single-walled carbon nanotubes in fish at levels as 

low as 100 ppb. Noted effects included respiratory stress, ventilation rate, gill mucus secretion, 

gill damage, and aggressive behaviors. Liver cell injuries were also readily apparent at these 

exposure levels and suggest the possibility of liver tumor formation over longer exposure periods. 

This response is also notable because effects were seen in cells closest to blood vessels, 

suggesting transport of respired or ingested single walled carbon nanotubes via the blood stream. 

Some effects in the gut lumen were also observed at these exposure levels. Further studies need 

to be conducted before EPA can determine a concentration of concern. Such studies must 

measure actual concentrations of carbon nanotubes and control for the effects of contaminants, 

solvents, and physical factors such as blockage of gills or intestines. Before such testing is 

conducted, advanced fate testing may also be needed to determine the environmental behavior. 

Baun, A., Hartmann, N.B., Grieger, K. Kusk, K.O., (2008). Ecotoxicity of Engineered 

Nanoparticles to Aquatic Invertebrates: A Brief Review and Recommendations for Future 

Toxicity Testing. Ecotoxicology. 17:387-395. 

Blaise, C. Gagne, F., Ferard, J.F., Eullaffroy, P., (2008). Ecotoxicity of Selected Nano-Materials 

to Aquatic Organisms. Environ. Toxicol. 23:591-598. 

Cheng, J., Flahaut, E., Cheng, S.H., (2007). Effect of Carbon Nanotubes on Developing 

Zebrafish (Danio rerio) Embryos. Environ. Toxicol. Chem. 26:708-716. 

Farre, M., Gajda-Schrantz, K., Kantiani, L., Barcelo, D., (2009). Ecotoxicity and Analysis of 

Nanomaterials in the Aquatic Environment. Anal. Bioanal. Chem. 393:81-85. 

Handy, R.D., Owen, R., Valsami-Jones, E., (2008). The Ecotoxicology of Nanoparticles and 

Nanomaterials: Current Status, Knowledge Gaps, Challenges, and Future Needs. Ecotoxicology. 

17:315-325. 

Hyung, H., Fortner, J.D., Hughes, J., Kim J.H., (2007). Natural Organic Matter Stabilizes Carbon 

Nanotubes in the Aqueous Phase. Environ. Sci., Technol. 41:179-184. 

Klaine, S.J., Alvarez, P.J.J., Batley, G.E., Fernandes, T.F., Handy, R.D., Lyon, D.Y., Mahendra, 

S., McLaughlin, M.J., Lead, J.R., (2008). Nanomaterials in the Environment: Behavior, Fate, 

Bioavailability, and Effects. Environ. Technol. Chem. 27(9):1825-1851. 
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Maynard, A.D., Baron,P.A., Foley, M., Shvedova, A.A., Kisin, E.R., Castranova, V. (2004). 

Exposure to Carbon Nanobube Material: Aerosol release During the Handling of Unrefined 

Single-Walled Carbon Nanotube Material. Journal of Toxicology and Environmental Health, 

Part A. 67(1):87-107. 

Mouchet, F., Landois, P., Sarremejean, E., Bernard, G., Puech, P., Pinelli, E., Flahaut, E., 

Gauther, L., (2008). Characterisation and in vivo ecotoxicity evaluation of double-wall carbon 

nanotubes in larvae of the amphibian Xenopus laevis. Aquatic Toxicol. 87:127-137. 

Petersen, E.J., Huang, Q., Weber, W.J., (2008). Ecological Uptake and Depuration of Carbon 

Nanotubes by Lumbriculus variegatus. Environ. Health Perspec. 116(4):496-500. 

Roberts, A.P., Mount, A.S., Seda, B., Souther, J., Qiao, R., Lin, S., Pu Chun Ke, Rao, A.M., 

Klaine, S.J., (2007). In vivo Biomodification of Lipid-Coated Carbon Nanotubes by Daphnia 

magna. Environ. Sci. Technol. 41:3025-3029. 

Smith, C.J., Shaw, B.J., Handy, R.D., (2007). Toxicity of Single Walled Carbon Nanotubes to 

Rainbow Trout, (Oncorhynchus mykiss): Respiratory Toxicity, Organ Pathologies, and other 

Physiological Effects. Aquatic Toxicol. 82:84-109. 

Templeton, R.C., Ferguson, P.W., Washburn, K.M., Scrivens, W.A., Chandler, G.T., (2006). 

Life-Cycle Effects of Single-Walled Carbon Nanotubes (SWNTs) on an Estuarine Meiobenthic 

Copepod. Environ. Sci. Technol. 40:7387-7393. 

Zhu, X., Zhu, L., Chen, Y., (2009). Acute Toxicities of Six Manufactured Nanomaterial 

Suspensions to Daphnia magna. J. Nanopart. Res. 11:67-75.