TI: Steven Cragg RAD Disposition Meeting PM: Zofia Kosim October 21, 2010

Revised January 12, 2009 with new exposure information and a revised NCEL

Risk Assessment for P09-417 (formerly X09-0004)

This Report Contains CBI Information

Background Information

P09-417, submitted by the CNano Corporation, is comprised of multi-walled nanotubes. The PMN is imported and expected to be used as an Electrical conductor in conductive polymers for anti-static and EMI appli cations (70%), a mechanical strength additive for liquid epoxy resins for numerous composites and adhesive applications (10%), and elec trical conductor in electrode materials for super-capacitor/battery applicatio ns (20%).

P09-417 is comprised of multiwalled carbon nano tubes (MWCNT) with the molecular weight, length, and diameter ranges stated below. The PMN particles are highly agglomerated resulting in a size range of 95% larger than 100 micrometers based on the particle sizing method of Dynamic Light Scattering (DSL), which is conduct ed in a fluid. Conseque ntly, at least 95% of the particles would not be expected to be respir able into the deep lung. Deep lung respirable particles are considered to have a maximum diam eter of 10 micrometers thus perhaps 99% plus percent may not be deep lung respirable. However, there is considerable uncertainty in the DSL

method since it is conducted in a fl uid and may miss smaller particles.

Physicochemical Properties (Chemistry Report)

Properties

Molecular

Formula: C Molecular Weight: 1000000.00

%<500: %<1000:

MP: MP Estimate: BP: BP Pressure (Torr): BP Estimate: >400

VP: VP Estimate: <0.000001

Water Solubility: Water Soluble

Estimate: <0.000001

Log P: Log P Estimate: Physical

State--Neat: Solid Physical State--

Manuf: NK: Import

Physical

State-- Processing: Solid: Physical State--End

Use: Solid:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 2 of 47 Chemical structure P09-417

Health Hazard Reports

Stated Concerns from the Stru cture/Activity Team (SAT) Report :

There are possible concerns for immunotoxicity, oncogenicity and mutagenicity based on analogs (SAT Report)

Absorption, Distribution, Metabolism, Excretion :

The PMN is expected to be poorly absorbed vi a all routes of exposure based on analogues. There are concerns for lung overload for poorly so luble particulates and for lung effects based on submitted test data (submitted with P09-417). There are possible concer ns for immunotoxicity, oncogenicity and mutagenicity based on analogs (SAT Report)

General Toxicity (D. Lai) :

A number of non-genetic in vitro and in vivo toxicity studies on the PMN substance were submitted. P09-417 appeared to show low/no cy totoxicity and pro-inflammatory effects on HepG2 cells, and low/no dermal t oxicity or sensitizing effects on in vitro reconstituted epidermis. However, in vitro assays have limited usefulness for hazard identification of nanoparticles due to a number of inherent issu es; several studies have shown no correlations

between in vitro and in vivo assays of some nanoparticles. Additional

Chemical

Info: The molecular weight is variable and de pends on the size of the nanotube

Estimated Data: BP > 400 °C (High MW); VP < 0.000001 torr (High MW); WS < 0.000001 g/L (High MW).Standard Review Risk Assessment for P09-417

January 12, 2010 Page 3 of 47 A 5-day inhalation study in rats showed moderate increases in several biochemical parameters in the bronchoalveolar lavage fluid (BALF) analysis and mild multifocal granulomatous inflammation in the lungs.

A 90-day inhalation study conducted by w ith P09-417 MWCNT’s revealed moderate granulomatous inflammation, severe alveolar histiocytosis, lipoproteinosis and minimal neutrophil infiltration

.

is another MWCNT analogous to P09-417 w ith m ore detailed info rmation regarding its dimensions. has an average diameter of and an average length of . exists as simple and comple x agglomerates of carbon nanotubes by weaving around each other and held together by van der Waals force. The carbon nanotube agglomerates are roughly spherical in shape a nd their dimensions range from a bout 10 to 100 μm. Some of the small agglomerates of (< 10 μm) are respirable in humans. Furthermore, the agglomeration strength is not very high and they are considered loose with empty space between

the individual carbon nanotube fibers. On ce deposited in the alveolar region, simple agglomerates of may dissociate to indi vidual carbon nanotubes wh en interacting with lung surfactant. Some research has suggested that carbon nanotubes may behave as asbestos fibers with similar consequences. Therefore, by analogy to asbestos fibers and based on data of some carbon nanaotubes (MWCNT and SWCNT), there is concern for pulmonary toxicity, fibrosis, lung cancer, and mesothelioma for these materials. Evidence in mice shows that carbon nanotubes can translocate from the respiratory tract to regional lymph nodes as well as penetrate to the pleural lining of the lung causing inflammation. In addition, there are data suggesting that pulmonary deposition of some nanoparticl es, including carbon nanotubes, may induce cardiovascular toxicity when inhaled.

Mutagenicity :

No mutagenicity data were provided with PMN P09-417. Based upon reports on similar materials, P09-417 (1) may induce gene mutations in mammalian cells in culture but not in prokaryotes or lower eukaryotes; (2) may be a weak inducer of an euploidy but not of structural

chromosome aberrations in mammalian cells in culture; (3) may induce DNA effects in mammalian cells in culture, but not in lower eukaryotes in vivo , and; (4) may not induce cell

transformation in mammalian cells in culture.

Due to uncertainty about their ability to penetrat e cells, testing of nanomaterials in genotoxicity assays is problematic, and negative responses wo uld not conclusively ru le out the potentialStandard Review Risk Assessment for P09-417

January 12, 2010 Page 4 of 47 mutagenicity hazard of nanotubule materials in hu mans. No testing of the PMN is recommended

at this time.

Immunotoxicity :

Based on published scientific data for similar multi-walled carbon nanotubes, P09-417 as the potential to cause immunotoxicity. Pulmonary exposure to this PMN may lead to reduced alveolar macrophage phagocytosis, impaired cl earance of inhaled bacteria, inflammation, possible systemic immunosuppressi on, and promotion of allergy.

Occupational Exposure :

From the submission, the stated use of P09-417 MWCNTs is to improve electrical, thermal and/or mechanical properties in plastics. Othe r uses for analogous MWCNTs in the past have been for reinforcing agents for ceramics in bulle t-proof vests, electrical conductors to enhance conductivity of electrodes fo r batteries, and as conductors (elect rical and thermal) for use in resin composites. Other uses are described in the attached engineering report.

The PMN will be imported as pure MWCNTs or mixed into “master batches” of plastic precursors containing from 0.5 to 20% MWCN Ts.

It is assumed that the PMN will be used in the production of plastics at sites operating 250 days/year with no direct exposure of th e general public. The number of workers is expected to range from per site.

Health Risk Assessment

The major health concerns for the PMN are for pot ential pulmonary toxicity, fibrosis and cancer to workers exposed via the inhalation route. There are also data suggesting that pulmonary deposition of some nanoparticles, including carbon nanotubes, may induce cardiovascular toxicity when inhaled. Scenario # Sites # Workers Release d/ yr Inhal (mg/d) Derm (mg/d) Processing 1: Incorporating CNTs

into Master Batches 250 0.0018 6

Processing 2: Incorporating CNTs into Coatings 250 0.2 worst-case 6-8

Use: Application of Coating to

Metal or Wood 250 Negligible 8Standard Review Risk Assessment for P09-417

January 12, 2010 Page 5 of 47 Hum an Health Testing Recommendation

The concerns for significant inhalation risk s are confounded by limited unde rstanding of both the health hazards and estimated exposures in this case. The need for testing is questionable because

Use of natural material that has not been micronized could be expected to provide a higher LOAEL than for unmicronized material (i.e., be toxic only at higher concentrations or not to xic at all). Thus, the findings in the rat study reflect artificially enhanced exposure not likely to be encountered in the work envir onment. If realistic particle sizes had been used in the rat study, the NCEL derived from it may have been enough higher to exceed estimated exposures.

Due to the great uncertainty in assessing particle sizes of the CNT’s, be tter characterization of actual particle size distributions of respirable particles in the wo rk environment is needed using instruments such as a cascade impactor. Defini tive particle-size distribution information would

indicate the need for and stru cture of subsequent toxicity testing on the PMN substance.

Personal Protective Equipment and Indus trial Hygiene Control Recommendations

Until such time as particle size information is better characterized, PPE and IH controls should include: a NIOSH-approved, full-face air-purifying particulate respirator with N, P, or R-100 filter, or hood respirator with an assigned prot ection factor (APF) of at least 25; permeation resistant gloves; and impervious clothing.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 6 of 47 Ecological Risk Assessment for P09-417

Hazard Assessment : This PMN and other carbon nanotubes (CNTs) have very low water solubility – estimated to be less than 1 μg/L (see chemistry report). As a result, one might expect

that the concentrations of CNTs in the water co lumn of surface water bod ies or in groundwater would be negligible with little or no adverse effects to aquatic sp ecies. However, reports in the

literature indicate adverse effects to aquatic species tested in th e laboratory at concentrations claimed to be above the expected water solubi lity limit. Reasons that might account for this apparent discrepancy include: 1) us e of artificial technique s to enhance the solubility of CNTs in the test media (e.g., with solvents ), or 2) contamination of CNTs used during manufacture that may leach out during solubilization and be the actual cause of any observe d toxicity at the CNT loading ra tes above anticipated solubility limits. Beyond this, CNTs may be derivatized w ith chemical moieties that confer desired performance properties for a variety of applicat ions. Some of these chemical moieties (e.g., hydroxylated derivatives, protein coats) may incr ease water solubility of CNTs, accounting for reported effects at concentrations higher than the theoretical sol ubility limit. With regard to exposure in the environment, greater than expected concentrations may be attained by CNTs in ambient waters due to the presence of organic pa rticulate matter such as humic acid or other forms of organic materials upon which CNTs may adsorb.

CNTs adsorbed onto in the water column or in sediments, if strongly bound, might be expected to show little toxicity to aquatic organisms. Or observed toxicity might be due to physical effects rather than direct chemical toxi city, such as particles adhering to gills thereby interfering with oxygen transfer, or blocking the gut of larval fish or copepods and causing

immobilization or death from this effect. A br ief review of the published literature follows.

Using “small scale” in vitro tests with a variety of microorga nisms, Blaise et al. (2008) found growth inhibition in Pseudokirchneriella subcapitata at a reported nominal concentration of 1 mg/L and no effects for other orga nisms. Actual concentrations were not reported.

Hyung et al. (2007) reported enhanced solubilization of MWCNTs in the presence of “natural organic matter” that remained stable for over 1 month at measured concentrations as high as 500 mg/L.

Mouchet et al (2008) studied the effects of double-walled CN Ts on larvae of Xenopus laevis exposed for 12 days at concentrations ranging from 10 to 500 mg/L. No genotoxicity (i.e., erythrocyte micronuclei) were f ound at any concentration but fra nk toxicity was observed at all concentrations, which the authors attributed to physical blockage of the gills and/or digestive

tract.

Petersen et al. (2008) evaluate d uptake and depuration of C 14 -radiolabeled single- and doublewalled CNTs on Lumbriculus variegatus finding little test substance accumulation in this sediment-dwelling species compared to pyrene.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 7 of 47 Roberts et al. (2007) facilitated solubilization of SW CNTs in water by coa ting with the lipid, lysophosphatidylcholine. Daphnia were subsequently exposed to and ingested the particles. The lipid coating was digested leaving the uncoated particle. The authors concluded that aquatic organisms could alter SWCNTs. Toxicity to the daphnia occurred at 10 mg/L or higher.

Smith et al. (2007) exposed juve nile rainbow trout to SWCNTs at concentrations of 0, 0.1, 0.25, or 0.5 mg/L (facilitated by the de tergent-like solvent, sodium dod ecyl sulfate and sonication) for up to 10 days under semi-static conditions monito ring a variety of endpoi nts including clinical observations, clinical chemistry, differential blood analysis, an d histopathology. Effects on the gill and brain were found that may be rela ted to the accumulation of SWCNTs on gills (inhibiting oxygen uptake) and/or to the sodium dodecylsulfate vehicl e rather than a direct toxic

effect of SWCNTs to fish.

Templeton et al (2006) found no sign ificant effects in full life-cy cle studies with the estuarine meiobenthic copepod, Amphiascus tenuiremis exposed either acutely or chronically to chemically purified SWCNTs at sedimentary c oncentrations of 0, 0.58, 0.97, or 1,5, or 10 mg/L (presumed to be loading concentrations).

Zhu et al. (2009) examined the acute toxicity (immobilization) of singl e- and multi-walled CNT suspensions to Daphnia magna . The 48-hr EC50s for SWCNTs was 1.3 mg/L and for MWCNTs was 8.7 mg/L. Reported exposure concentr ations are presumed to be nominal. When examined microscopically, large amounts of bl ack material were found in the guts of the daphnids which may have accounted for the toxicity.

To summarize, toxicity from exposure to CNTs ha s been reported in multiple aquatic species at concentrations much higher than estimated sol ubility limits. Various techniques have been employed to increase solubili zation and creation of stable suspensions. Most reported concentrations are nominal with high loading rate s. Actual concentratio ns have rarely been reported. Thus, the actual concentrations may be much less than reported. In those studies that have reported significant toxicit y, the reported adverse effects ma y have been due to: 2) toxic so lvent vehicles; 3) physic al disruption of oxygen transport via the gills, or; 4) intestinal blockage after ingestion of CNTs rather than direct toxicity from CNTs.

Further studies need to be conducted before a co ncentration of concern may be derived. Such

studies must measure actual concentrations of CNTs and must control for the effects of contaminants, solvents, and physical factors su ch as blockage of gills or intestines.

Ecological Exposure Assessment : The average surface water concentration of these materials cannot be predicted reliably with the present state of knowledge (EPA/EETD). Moreover, in the aquatic ecotoxicity studies conducted to date, the analytical charac terization of the CNTStandard Review Risk Assessment for P09-417

January 12, 2010 Page 8 of 47 concentrations has been poor or not performed for most of the investigations. Rather, nominal or loading rate concentrations have been relied upo n. For most of the studies, attendant toxicities

have been associated with these nominal concen trations without a true understanding of actual

concentrations.

Ecological Risk Characterization : Consequently, the risk of such materials to aquatic organisms in the environment cannot be determined quant itatively by comparing predicted surface water

concentrations with a concentration of concern. Qualitatively, risk to aquatic organisms from the chemical characteristics of CNTs might be expe cted to be low because of the extremely low solubility of these materials in water. No eco toxicity testing is recommended at this time.

References:

Blaise, C. Gagne, F., Ferard, J.F., Eullaffroy, P ., (2008). Ecotoxicity of Selected Nano-Materials to Aquatic Organisms. Environ. Toxicol . 23:591-598.

Hyung, H., Fortner, J.D., Hughes, J., Ki m J.H., ( 2007). Natural Organic Matt er Stabilizes Carbon Nanotubes in the Aqueous Phase. Environ. Sci., Technol. 41:179-184.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 9 of 47 Mouchet, F., Landois, P., Sarremejean, E., Bern ard, G., Puech, P., Pinelli, E., Flahaut, E., Gauther, L., (2008). Characteris ation 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 Biomodificat ion of Lipid-Coated Carbon Nanotubes by Daphnia

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

Smith, C.J., Shaw, B.J., Handy, R.D., (2007). To xicity of Single Walled Carbon Nanotubes to Rainbow Trout, (Oncorhynchus mykiss): Respirat ory Toxicity, Organ Pa thologies, 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 Toxi cities of Six Manufactured Nanomaterial Suspensions to Daphnia magna . J. Nanopart. Res. 11:67-75.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 10 of 47 

## Appendices

Structure Activity Report (SAT) (J. Kwait) Page 11 Human Health Review (D. Lai) Page 14 Immunotoxicity (R. Ward) Page 19 Genotoxicity (M. Cimino) Page 22 Chemistry Report (D. Darling) Page 26 Engineering Report (F. Arnold) Page 29 Exposure Report (C. Cinalli) Page 40 Economics Report (K. Loughery) Page 43Standard Review Risk Assessment for P09-417

January 12, 2010 Page 11 of 47 

### SAT Report

PMN Number: P-09-0417

SAT Date: 3/10/2009

Print Date: 9/4/2009

Related cases: CBI: Yes

Health related cases:

Ecotox related cases:

Concern levels:

Type of Concern: Health Eco Comments

Level of Concern: 2 1

Persistence Bioaccum Toxicity Comments

3 U

Exposure Based Review:

Health: No

Ecotox: No

Routes of exposure: Health: Inhalation, dermal, drinking water

Ecotox: No releases to water

Fate: ;

Keywords: Keywords: LUNG

IMMUNO

UNCERT MUTA

ONCO

Summary of Assessment:

Fate: Fate Summary:

FATE:

Solid S < 0.001 mg/L at 25 EC (E) VP < 1.0E-6 torr at 25 EC (E) BP > 400 EC (E) H < 1.00E-8 (E) POTW removal (%) = U via U Time for complete ultimate aerobic biodeg = UStandard Review Risk Assessment for P09-417

January 12, 2010 Page 12 of 47 Sorption to soils/sediments = U

PBT Potential: P3BU *CEB FATE: Migratio n to ground water = U

Health:

Health Summary: Expect poor absorption via all routes (analog). There is concern for lung overload for a poorly soluble particulate, and fo r lung effects, based on submitted test data. Possible concerns for immunotoxicity and oncogeni city, and uncertain concern for mutagenicity, based on analogs.

Test Data: Submitted with the PMN:

Rat acute (inhalation) toxicity with moderate in creases in total protein and enzymes at all doses and in creased lung weights an d lung discoloration at higher doses;

Rat acute oral with no toxic signs (summary only; unclear data) Rat 90 D inhalation toxicity with adverse lung effects; In vitro human skin model test showed no cytotoxicity or irritation

Submitted with Rat acute oral (gavage) toxicity LD50 > 2000 mg/kg; Not a dermal irritant in rabbits; Mild eye irritant in rabbits

Ecotox:

Test Organism Test Typ

e Test End

Point Predicted Measured Comments

fish 96-h LC50 * daphnid 48-h LC50 * green algal 96-h EC50 *

fish chronic value * daphnid _ chronic

value *

algal _ chronic

value *

Sewa g e Sludge 3-h EC50 _

Sewa g e Sludge _ Chronic

Value _

Ecotox Values Comments: Predictions are based on SARs fo r neutral organic chemicals; SAR chemical class = C-graphite-multi-walle d carbon nanotubes; MW>1,000,000; solid; logStandard Review Risk Assessment for P09-417

January 12, 2010 Page 13 of 47 Kow >> 10 (P); S = negligible; pH7; effectiv e concentrations based on 100% active ingredients and nominal concentrations; DW hardness < 15 0.0 mg/L as CaCO3; and DW TOC <2.0 mg/L;

Factors Values Comments

Assessment Factor 10

Concentration of Concern (ppb) *

SARs neutral organic chemicals SAR Class carbon allotrope

Ecotox Factors Comments:

SAT Chair: J. KwiatStandard Review Risk Assessment for P09-417

January 12, 2010 Page 14 of 47 April 24, 2009

MEMORANDUM

SUBJECT: Health Hazard Review of X-09-4

FROM: David Lai (ECAB/RAD)

TO: Steve Cragg (NCSAB/RAD)

THRU: Jennifer Seed (ECAB/RAD)

Attached is my review of the health hazard potential of the subject PMN. Please contact me should you have any questions regarding this review.

This memo. contains Confidential Business Information.

Attachment

cc: Bob Morcock

Health Hazard Review of X- 09-4 (Re-Designated P09-417)

I. CONCLUSION

X-09-4 contains multiwalled carbon nanotubes (MWCNT) with an

Therefore, the PMN are mostly are not expected to be respirable to the lungs and permeable to

the skin.

A number of in vitro and in vivo toxicity studies on the PMN substance were submitted. X-09-4 appeared to show low/no cytotoxicity and proinflammatory eff ects on HepG2 cells, and low/no dermal toxicity or sensitizing effects on in vitro reconstituted epidermis. However, in

vitro assays have limited usefulness fo r hazard identification due to a number of inherent issues;

seversl studies have shown no correlations between in vitro and in vivo assays of some nanoparticles. A 5-day inhalation study in ra ts showed moderate increases in several biochemical parameters in the bronchoalveolar lavage fluid (BALF) analysis and mild multifocal granulomatous inflammation in the lungs. A 90-day inhalation study revealed moderate granulomatous inflammation, severe alveolar histiocytosis, lipoproteinosis and minimal neutrophil infiltration at 2.5 mg/m 3 . The histopathological findings at lower concentration levels were similar to those observed at 2.5 mg/m 3 but of less severity. The No Observed Effect Concentration (NOEC) was 0.1 mg/ m 3 . The aerosol of X-09-4 in these inhalation studies wereStandard Review Risk Assessment for P09-417

January 12, 2010 Page 15 of 47 generated by brush particle generators to re spirable sizes (MMAD: 0.5-2.0 μm) and may not be representative to the PMN substance being expo sed to workers or the general populations.

II. BASIS OF CONCLUSION

X-09-4 contains multiwalled carbon nanotubes (MWCNT)

the PMN are mostly are not expected to be respirable to the lungs and permeable to

the skin.

A number of in vitro and in vivo toxicity studies on the PMN substance were submitted. These studies were conducted following OECD gu idelines for the Testing of Chemicals.

1. In Vitro Assays

X-09-4 were suspended in an aqueous solution and dispersed by agitation and

sonication.

In order to investigate th e potential cytotoxicity of the PMN substance, the hum an hepatoma cells HepG2 were incubated with X-09-4 at concentrations of 100 μg/ml, 500 μg/ml, and 1 mg/ml for 24 hrs. or 48 hrs. X-09-4 did not induce LDH release, caspase-3 activation and secretion of IL-8 in HepG2 cells, suggesti ng that the PMN substance may have low/no cytotoxicity and pro-inflammatory effects on HepG2 cells.

In order to determine whether X-09-4 are ab le to cross the cornified layer and induce morphological changes in epidermis, epidermis r econstituted from human keratinocytes with a

functional stratum corneum were incubated w ith the PMN substance as dry powders (2.5 mg/cm 3 ) directly deposited on the cornified layers for 24 hrs.or 72 hrs. No cytotoxicity, irritation, sensitizing effects, nor any local cell damages were obs erved, suggesting that X-09-4 is not able to cross the cornified layers of epidermis.

2. In Vivo Studies

A. Acute (5-day) Inhalation study

.

To determine the appropriate concentrati ons for a 90-day subchr onic inhalation study, a 5-day range finding study wa s carried out with X-09-4. Groups of8 male Wistar rats were headnose exposed to respirable dusts of the PMN substance at 2, 8, and 32 mg/m 3 6 hr/day for 5 days. The aerosol of X-09-4 were genera ted by brush particle generators and the sizes of the generated aerosol (Mass Median Aerodynamic Diameter/MM AD: ) were within the respirable range ( ). Animals were sacrificed on study day 7 and 28. Five animals/group underwent bronchoalveolar lavage fluid (BALF) analysis and 3 animals/group were used for histopatho logical examination.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 16 of 47 Examination of the BALF showed moderate in creases of total protei ns, total cell counts and enzymes in all test groups as compared to the controls. Some effects were reversible at the low concentration, whereas other effects, such as polymorph nuclear gr anulocytes activation were still observed, albeit less pronounced, afte r a 3-week recovery period. Gross necropsy

examination showed the absolute and relative lung weights were significantly increased in animals exposed to 8 and 32 mg/m 3 . These increases were still measured in the high-dosed rats after a 3-week recovery period. Histopathol ogical examination showed a concentrationdependent multifocal granulomatous inflamma tion accompanied by diffuse histiocytosis, hyperplasia/-trophy of the bronchial epithelium and granulocytic in filtration in the lungs of the

treated rats.

B. Subchronic (90-day) Inhalation study

.

Groups of 10 male and 10 female Wistar rats were exposed nose-only to dust aerosol of the PMN substance at 0, 0.1, 0.5, and 2.5 mg/m 3 6 hr/day, 5 day/week for 90 days.. The MMAD of the aerosol generated by brush particle generators ranged between During necropsy, the absolute and relativ e lung weights were significantly increased in animals exposed to 0.5, and 2.5 mg/m 3 . Histopathological examination showed moderate granulomatous inflammation, severe alveolar histiocytosis, lipop roteinosis and minimal ne utrophil infiltration at 2.5 mg/m 3 . The histopathological findings at 0.5 mg/m 3 were similar to those observed at 2.5 mg/m 3 but of less severity. At 0.1 mg/m 3 , granulomas were also seen in one male and 4 of the 10 female rats. Based on these findings, the No Observed Effect Concentration (NOEC) is 0.1 mg/m 3

.

Summary and Discussions

X-09-4 appeared to show low/no cytotoxic ity and proinflammatory effects on HepG2 cells, and low/no dermal toxic ity or sensitizing effects on in vitro reconstituted epidermis.
However, in vitro assays have limited usefulness for h azard identification due to a number of inherent issues; severa l studies have shown no correlations between in vitro and in vivo assays of some nanoparticles

In the acute and subchronic inhalation st udies, findings in both BALF analysis and histopathological examination indicate a pulmonary carcinogenicity potential of the test materials. These findings are not too surprisi ng because the test mate rials are long and thin carbon nanotubes with a high aspect ratio, and therefore, may exhibit some of their effects (through oxidative stress and inflammation) as asbe stos fibers (Donaldson et al., 2006). A recent panel review has identified many similarities be tween high aspect ratio nanoparticles (HARN) and asbestos with regard to their physicochemi cal properties and toxico logical effects and has

concluded that there is sufficient evidence to suggest that HARN which have the same characteristics (diameter, length and biopersisten ce) as pathogenic fibers are likely to have similar pathology (Tran et al., 2008). Studies conducted by Lam et al. (2004) and Warheit et al.(2004 ) examining the pulmonary toxicity of SWCNT by intratracheal instillation in mice and rats, respectively, have both reported an ep ithelial granulomatous reaction to SWCNT. Exposures to MWCNT by pharyngeal aspiration (Wol farth et al., 2009) or by short-term (up to 8 days) or subchronic (90-days) inhalation (Lands iedel et al., 2009; Port er et al., 2009) haveStandard Review Risk Assessment for P09-417

January 12, 2010 Page 17 of 47 resulted in dose-dependent increases in pulmonary inflammation and evidence of fibrosis in rats and mice. Exposing the mesothelial lining of the body cavity of mice (a s a surrogate for the mesothelial lining of the chest cavity) to long MW CNT by injection has result ed in asbestos-like, length-dependent, pathogenic behavior (Poland et al., 2008). Evidence that MWCNT can cause persistent pulmonary inflammation, can be translo cated from the lung to the regional lymph node and can penetrate the pleura to cause pleura l inflammation has indeed been shown in mice exposed by pharyngeal aspiration (Hubbs, et al., 2009) or by i nhalation (Bonner et al., 2009).

However, the aerosol of X-09-4 in these i nhalation studies were generated by brush particle generators to respirab le sizes (MMAD: 0.5-2.0 μm) and ma y not be representative to the PMN substance being exposed to workers or the general populations. of the PMN substance is expected to modify many of the physicochemical properties ( e.g., surface properties) which are important for their toxicity/carcimnogenic ity have shown that preparation of a MWCNT test sample by can lead to generation of surface structural defects and chemically reactive oxidation site s in the carbon nanotube framewor k. Photomicrographs of the

nanotube structures of another PMN substance before and after the illustrating the disrupti on of the nanotubes from a solid to lacey surface has been

shown.

III. TEST RECOMMENDATION

According to the submission, the agglomerated PMN particles are embedded in a polymeric matrix, and as such, human exposures are expected to be negligible. No further testing is recommended unless there is evid ence that this PMN substance will be deagglomerated to respirable sizes during processi ng or uses. In that case, a 2-yr. inhalation bioassay in rats is recommended for the samples generated.

REFERENCES

Bonner, J.C. et al., 2009. Inhaled multi-wa lled carbon nanotubes stimulate a pleural inflammatory response in the lung of mice. SOT Abst. NO. 2205.

K. Donaldson, R. Aitken, L. Tran, V. Stone, R. Duffin, G. Forrest, a nd A. Alexander, Carbon

nanotubes: A review of their properties in relation to pulmo nary toxicology and workplace safety, Toxicol. Sci.

, 92 , 5-22, 2006.

Hubbs, A. et al., 2009. Persistent pulmonary inflammation, airway mucousmetaplasia and migration of multi-walled carbon nanotubes from th e lung after subchronic exposure. SOT abst.

No. 2193.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 18 of 47 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. Muller, J. et. Al., 2005. Respiratory toxicity of multi-wall carbon nanaotubes. Toxicol Apply.

Pharmacol. 207: 221-231.

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

Abst. No. 2194.

Poland, C.A., R.Duffin, I. Kinloch, A. Maynard , W.A.H. Wallace, A. Seaton, V. Stone, S. Brown, W. MacNee, and K. Donaldson, Carbon na notubes introduced into the abdominal cavity of mice show asbestos-like pathog enicity in a pilot study. Nature Nanotechnology 3 , 423 – 428,

2008.

Porter et al., 2009. Pulmoanry toxicity in inha led multi-walled carbon nanotubes. SOT Abst. No.

2195.

Tran, C.L. et al., 2008. An outline scoping stud y to determine whether high aspect ratio nanoparticles (HARN) should raise the same con cerns as do asbestos fibres. Institute of Occupational Medicine, UK, Re port on Project CB0406, August 13.

Warheit D.B. et al. 2004. Comparative Pulmonary Toxicity Assessmen t 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.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 19 of 47 04/27/09

MEMORANDUM

X09-0004 has been re-designated P09-417

SUBJECT: X09-4: Immunotoxic ity Standard Review

FROM: Ronald E. Ward Ph.D., Microbiol ogist/Immunologist RAD/SSB (7403M)

THRU: Donald Rodier, Branch Chief RAD/SSB (7403M)

TO: Steve Cragg Ph.D., T echnical Integrator NCSAB (7403M)

TSCA CONFIDENTIAL BUSINESS INFORMATION

Conclusion: Based on published scientific data analogs, (Multi-walled carbon nanotubes) would be an immunotoxi city hazard. Pulmonary exposure to this PMN may lead to reduced alveolar macrophage phagocytosis, impaired clearance of inhaled bacteria, inflammation, possible systemic immunos uppression, and promotion of allergy.

Basis for Conclusion: X09-4 will be used as a plastics additive to improve electrical, thermal and/or mechanical properties (1). This PMN will be poorly absorbed into the body via all routes (2). Since there were no immunotoxicity data associated with this PMN, the conclusions reached here are based on analog published scientific data. This PMN consists of nano-sized particles. There is a concern that nano-sized particles, having an increased surface area per unit mass, may be more toxic than larger particles. Due to the concerns over the risk of nanomaterials, there has been a recent increase in nanomaterialrelated safety research. In addition, seve ral related reviews have been published.According to two recent reviews (3,4), most research supports the idea that both multiwalled and single-walled carbon nano tubes have the potential to cau se pulmonary toxicity. Once taken up by humans, carbon nanotubes may cause oxidative stress, inflammation, and cell damage leading to effects like granulomas, fibros is and wall thickening. The review by Stern et al.(4) lists 7 published rodent pul monary CNT toxicity studies. All but one showed evidence of lung toxicity.

Studies in the literature also support the idea that both local pulmonary immunity and systemic immunity can be impacted followi ng CNT inhalation. Alve olar macrophages are important in both innate and adapti ve immunity in the lung. These ce lls play a central role in the defense against respiratory bacteria , virus, and fungal infections. In a recent publication, Shvedova and coworker s (5) showed that intratracheal instillation of SWCNT in mice not only elicited inflamma tion and lung damage, but also caused a delayed

clearance of Listeria monocytogenes . In their experiments, C57Bl/6 mice were given SWCNT (0, 10 and 40 μ g/mouse via pharyngeal aspirations ) and 3 days later exposed to Listeria

monocytogenes (10 3 bacteria/mouse). Exposure to both SWCNT and Listeria monocytogenesStandard Review Risk Assessment for P09-417

January 12, 2010 Page 20 of 47 amplified lung inflammation and collagen form ation. Despite this inflammatory response, SWCNT pre-exposure significantly decr eased the pulmonary clearance of Listeria

monocytogenes measured 3 - 7 days after microbial in fection relative to controls. Decreased bacterial clearance in SWCNT pre-exposed mice wa s associated with decr eased phagocytosis of bacteria by macrophages and a decrease in nitr ic oxide production by these phagocytes. These results support the idea that SWCNT exposure may lead to in creased susceptib ility to lung infections in exposed populations. Systemic immunotoxicity to inhaled multiw alled carbon nanotubes was the subject of a recent published study (6). In this study, C57BL/ 6 adult (10-12 weeks old) male mice were exposed via whole body inhalation to control air or 0.3, 1, or 5 mg/m 3 respirable aggregates of MWCNTs (diameter=10-20 nm and length=5-15 μ m) for 7 or 14 days (6 hr/day). (In a later publication, this material was shown to be a mixt ure of MWCNTs and nanofibers.) At the end of this period, pulmonary injury was analyzed us ing standard measures including histopathology, WBC count, and some measurements of oxidative st ress and cytokine induction. In addition, the ability of this substance to cause sy stemic immunosuppression was analyzed. The histopathology results of th is study showed that particul ate material was contained in alveolar macrophages, but no inflammation or tissu e damage was observed. Bronchial alveolar lavage fluid analysis also dem onstrated particle-laden macropha ges, with no increase in WBC count. However, MWCNT/nanofiber exposure of 0.3 mg/m3 and higher concentrations caused systemic immunosuppression after exposure for 14, but not 7, days. The immunosuppression was characterized as a reduced T-cell dependent antibody response to sheep erythrocytes, as well as a reduced T cell proliferation induced by conc anavalin A, a T cell mitogen. Animals exposed to 1 mg/m3 also had decreased NK cell function. These results showed that, even though the nanoparticle material caused no pulmonary inju ry or inflammation, MWCNT/nanofiber mixture exposure resulted in systemic immunosuppression. To help elucidate a mechanism, the authors of this report found that the mRNA levels for the cytokine interleukin-10 (IL- 10) and the enzyme NAD(P)H oxidor eductase 1 (an indicator of oxidative stress) were increased in the spleen, but not the l ung, upon 14 day exposure. These authors suggest that oxidative stress and IL-10 may play role s in inducing immunosuppression. In a recent publication, (7) MW CNTs have also been shown to promote allergic immune responses in mice. This publication show ed that both MWCNT and SWCNT could act a adjuvants and help promote airway inflammation and a specific IgE response to ovalbumin upon inhalation exposure in BALB/c mice. Collectively, these results support the idea that X09-4 would be a potential immunotoxicity hazard. Pulmonary exposure to this PMN may lead to reduced alveolar macrophage phagocytosis, impaired clearance of inhaled bacteria, inflammation, possible systemic immunosuppression, and promotion of allergy.

References

3. Helland, A. et al. Reviewing the Environmen tal and Human Health Knowledge Base of Carbon Nanotubes. EHP 115 (8), 1125-1131 (2007). 4.Stern, S, and McNeil, S. Nanotechnology Safety Concerns Revisited. Tox. Sci. 101, 4-21 (2008).Standard Review Risk Assessment for P09-417

January 12, 2010 Page 21 of 47 5. Shvedova, A. et al. Sequential Exposure to Carbon Nanotubes and Bacteria Enhances Pulmonary Inflammation and Infectivity. Am. J. Respir. Cell Mol. Biol ., Volume 38, Number 5, May 2008, 579-590. 6. Mitchell, L. A. et al. Pulmonary and Systemic Immune Response to Inhaled Multiwalled Carbon Nanotubes. Toxicological Sciences 100 (1), 203-214 (2007). 7. Nygaard U.C. et al. Single-walled and Mu lti-walled Carbon Nanotubes Promote Allergic Immune Responses in Mice. Tox. Sci., 2009.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 22 of 47 April 6, 2009

MEMORANDUM

Since this review, X09-004 was re-designated P09-417

SUBJECT: Mutagenicity Hazard Review of X09-4

FROM: Michael C. Cimino, Ph.D. Biologist Science Support Branch Risk Assessment Division (7403M)

TO: Steven Cragg, PhD, DABT Technical Integrator Existing Chemicals Assessment Branch

THRU: Donald Rodier

Branch Chief Science Support Branch Risk Assessment Division (7403M)

THIS MEMORANDUM CONTAINS

TSCA CONFIDENTIAL BUSINESS INFORMATION

I. CONCLUSION

No mutagenicity data were provided w ith PMN X09-4. Based upon reports on similar materials, X09-4 (1) may induce gene mutations in mammalian cells in culture but not in prokaryotes or lower eukaryotes; (2) may be a weak inducer of an euploidy but not of structural

chromosome aberrations in mammalian cells in culture; (3) may induce DNA effects in mammalian cells in culture, but not in lower eukaryotes in vivo , and; (4) may not induce cell

transformation in mammalian cells in culture.

Due to uncertainty about their ability to penetrate cells, testing of nanomaterials in genotoxicity assays is problema tic, and negative responses would not conclusively rule out the potential mutagenicity hazard of nanotubule mate rials in humans. No testing of the PMN is

recommended at this time.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 23 of 47 II. STRUCTURE OF X09-4 (i.e., P09-417) AND ANALOGUES

III. BASIS FOR THE CONCLUSIONS

No mutagenicity data were provided with the Premanufacturing Notice on PMN X09-4 (Multi-walled carbon nanotubes; no CAS#; ; st ructures in Section II).

A document provided in the notice by “Nanocyl” states that an in vitro gene mutation assay in mammalian cells on multiwall carbon nanot ubes (MWCNT) will be conducted. It states that, as part of the test, a determination is made on cellular cytotoxicity, which is characterized as “a pre-requisite before genotoxicity”. It is al so stated that MWCNT is not cytotoxic. These statements imply that genotoxicity is not possibl e unless cytotoxicity is obtained. This is decidedly not the case, and not th e reason cytotoxicity is determin ed in mutagenicity assays. Rather, cytotoxicity is determined in order to set dose levels. To have genotoxicity without any cytotoxicity is certainly possible.

The only basis for concern for this PMN is that it is a nanotech material. Nanotech analogues of the PMN have been reviewed in detail previously

are structurally identical to X09-4. Both were tested and found not to be gene mutagens in Salmonella strains TA98, TA100, TA102, TA1535 and TA1537 and in Escherichia coli strain WP2 uvrA , and not chromosome mutagens in mammalian CHL cells in vitro , in both cases without and with metabolic activation ( ).

(Open-ended multi-walled scrolled nanotubes; synonyms: also was not a gene mutagen in

Salmonella strains TA98, TA100, TA102, TA1535 and TA1537, and was not a chromosome mutagen in mammalian V79 cells, in both cases w ithout and with metabo lic activation

The data on carbon-based nanoparticles are summ arized in the Table that follows (all data except for a nd SWCNT are as reported in abstracts):Standard Review Risk Assessment for P09-417

January 12, 2010 Page 24 of 47 TABLE I: MUTAGENICITY DATA ON NANOTECH PRODUCTS

Gene mutations Chromosome

mutations DNA Other Chemical

SAL lower eukaryotes mammalian in

vitro CA

vitro MN

vitro Cell

transformation

neg neg

neg neg

neg neg

SWCNT neg weak pos comet vit

CNT pos ES vit neg rat BFU viv neg neg SCE vit

[5,6]FullereneC60-ih pos

neg neg SMART neg SMART neg BALBc

carbon black pos pos L51 pos SCE vitro

Abbreviations:

BFU = body fluid urine

CA = chromosome aberrations ES = mouse embryonic stem cells L51 = mouse lymphoma cells

MN = micronucleus neg = negative pos = positive

SAL = Salmonella SCE = sister chromatid exchange

SMART = somatic mutation and

recombination test in Drosophila

vit = in vitro

vv = in vivo weak = weakly positiveStandard Review Risk Assessment for P09-417

January 12, 2010 Page 25 of 47 As a nanotech material, X09-4 may be a weak inducer of aneuploidy a nd of DNA effects in mammalian cells in culture. Based upon reports on si milar materials, it may induce gene mutations in mammalian cells in culture but not in pr okaryotes, lower eukaryotes, or mammals in vivo ; it may not induce DNA effects in lower eukaryotes in vivo , nor cell transformation in mammalian cells in culture.

Due to uncertainty about their ability to penetr ate cells, testing of nanomaterials in genotoxicity assays is problematic, and negative responses wo uld not conclusively ru le out the potential mutagenicity hazard of nanotubule ma terials in humans. No testi ng of the PMN is recommended at

this time.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 26 of 47 EETD Standard Review Report ICB Chemistry Section

Case Number : X-09-4 CBI : Yes

Chemist : Dr. Diana Darling Date : 4/06/2009

Submitter : Nanocyl Corporation (a Georgia Corporation) [The foundation of Nanocyl, which was established in 2002 in Belgium, stems from the research work of Professor Janos B. Nagy of the University of Namur and Professor Jean-Paul Pirard of the University of Liege.]

Chemical Name: Short tangled multi-wall carbon nanotubes [The submitter claims that there are two kinds of nanotubes, short tangled nanotubes and long rigid

nanotubes.

CAS No : NA

Categorical Name : Carbon nanotube

Trade Name:

Structure :

Use : Plastic (therm oset and thermopl astic) additive to improve electric al, thermal, and/or mechanical propertiesStandard Review Risk Assessment for P09-417

January 12, 2010 Page 27 of 47 Chemical properties affecting exposure and releases :

Physical Form: Amorphous black powder

Molecular Formula: C

x Molecular Weight: > 100,000 (est) Vapor Pressure: < 0.0000001 torr (est) Water Solubility: < 0.000001 g/L (est)

Explodability : Kst = 42 bar*m/sec (VDI). Stable up to 480 °C in an oxidative atmosphere

By-products:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 28 of 47 None reported

General Nanotube information: Different types of nanotubes can be forme d, depending on which direction the "graphite sheet" appears to be rolled to form the nanot ube. These types of na notubes are denoted by a pair of integers, n and m, and are called armcha ir (n=m), zigzag (n=0 or m=0), and chiral (any other n and m). The integers n and m represen t the magnitude of vectors which add up to the diameter of the nanotube, and cannot be adequa tely described without an illustration. Armchair SWNTs are considered metallic, presumably because of their conductivity. SWNTs where n-m is divisible by 3 are semiconduc tors with a tiny band gap. All others are semiconductors, whose band gap depends on the re lative values of n and m, as well as the

nanotube diameter. The incorporation of 5- and 7-member rings in to a nanotube can cause it to bend or kink, or to change at a point along its length from one type to another (i.e. one part of the nanotube being armchair and another part being zigzag). The sidewalls of nanotubes can be chemically modified, either covalently or non-covalentl y. The zigzag and armchair types of nanotubes

are so named because when the nanotube is cu t perpendicular to the tube axis, the pattern around the periphery of the tube edge resembles e ither a zigzag pattern or the arm and seat of an armchair repeated n times. Nanotubes are the stiffest known fiber, with a Young's modulus of 1-1.4 TPa. They have an expected elongation to failure of 20-30%, which combined with their stiffness, projects to a tensile strength above 100 GPa, by far the highest known.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 29 of 47 STANDARD REVIEW ENGINEERING REPORT CBI: Yes

PMN: 09-0417 Focus Ready Draft 3/19/2009 Standard Review Report 6/22/2009
Revised 10/26/2009 **Revised 11/04/2009** ENGINEER: Arnold \ AG
PV (kg/yr): Import Only

SUBMITTER: Nanocyl Corporation

USE: Plastics additive to improve electrical, thermal, and/or mechanical properties; **additive to coatings**

.

OTHER USES:

MSDS: Yes Label: No

Gen Eqpt: protecting gloves (e.g. nitrile rubber, thickness greater than 0.35 mm) / chemical goggles or safety glasses Respirator: suitable respiratory equipment with High Efficiency Dust Cartridge (at least a P2 filter) when directly exposed or handling the powder Health Effects: contact with eyes may cause irritation due to abrasive action of the dust; not expected to cause prolonged or significant eye irritation / skin contact: no known hazards, but may be mildly irritating to the skin; it is not expected to be absorbed through the intact skin / inhalation of the dust from this material may cause respiratory irritation / ingestion: no known hazards; not expected to be harmful if swallowed / acute and chronic health effects: high concentration of dusts may be irritating to eyes, skin, mucous membranes and respiratory tract; no applicable chronic information at this moment, but none of the components is known to be a carcinogen or a suspected carcinogen

TLV/PEL:
Carbon nanotubes 2.5 ug/m^3 LOAEC (Low Observed Adverse Effect Concentration) Nanocyl recommends a LOAEC of 0.1 mg/m^3 and applies a safety factor of 40 to achieve an air threshold of 2.5Standard Review Risk Assessment for P09-417

January 12, 2010 Page 30 of 47 ug/m^3.

CRSS :

Chemical Name: Multi-walled carbon nanotubes
S-H20: 0.000001 g/L @

VP: 1.0E-6 torr @

MW: %<500 %<1000 Physical State and Misc CRSS Info: Neat: Solid Mfg: NK: Import Proc/Form: NK End Use: Solid: LVE material entrained within polymer. The molecular weight is variable and depends on the size of the nanotube. It is expected to be much greater than 100,000 g/mole. The submitter claims that there are two kinds of nanotubes, short tangled nanotubes and long rigid nanotubes.

Submitted Data: Burns before melting; Insoluble in water;

9

Estimated Data: BP > 400 °C (High MW); VP < 0.000001 torr (High MW); WS < 0.000001 g/L (High MW).

Consumer Use: No

SAT (concerns) (03/10/2009):

Related Cases and Related Cases and Misc SAT Info:

Migration to groundwater: Unknown PBT rating: P3BT PBT: P3; B Unknown; T Unknown Health: 2 Dermal, Drinking Water, Inhalation

Eco: 1 No releases to Water

OCCUPATIONAL EXPOSURE RATING: 1-2B

NOTES & KEY ASSUMPTIONS: Generated by the 06/07/2005 version of ChemSTEER. This

submission is a LOREX case. This submission is for multi-walled carbon nanotubes (MWCNTs). Note that some air monitoring data for packaging the CNTs is provided in the attached dossier on page 26. This dossier also provides explanation of some risk management practices including engineering controls used (butterfly valves). See contact report. The following past cases were referenced for consistency:

/// For IMPORT: Technical contact indicated up to
20 customers for max PV (note this is an estimate). Submitter

will offer CNTs to customers either as 100% raw CNTs or as incorporated into master batches. As customer choices are uncertain (choices have not been made yet), CEB assesses 100% ofStandard Review Risk Assessment for P09-417

January 12, 2010 Page 31 of 47 PV imported as raw CNTs (100% powder). Technical contact noted that it is possible some customers may hire another company to incorporate raw CNTs into master batches for them. CEB assumes this would not alter the total number of sites that produce master batches. /// For PROC (production of master batches): The current IRER assesses sites operating 250 days/year as default as actual production days/year are uncertain (see contact report). Consistent with past cases:

**Amendment received on**
**3 November 2009 indicates the usage of CNTs sold as powder will in the same**
**applications as stated for other applications and in the same proportions.**

POLLUTION PREVENTION CONSIDERATIONS:

None.

EXPOSURE-BASED REVIEW: NoStandard Review Risk Assessment for P09-417

January 12, 2010 Page 32 of 47 STANDARD REVIEW ENGINEERING REPORT CBI: Yes

PMN: 09-0417

Processing:

Number of Sites/ Location:

Unknown Cus mer Sites
Days/yr:

Basis:

Process Description:

ENVIRONMENTAL RELEASES ESTIMATE SUMMARY IRER Note: The daily releases listed for any source below may coincide with daily releases from the other sources to the same

medium. //

Incineration or Landfill Output 2: 4.0E-2 kg/site-day over 250 days/yr from
or 2.0E+2 kg/yr

to: Incineration

f

basis:

Incineration Output 2: 4.0E-2 kg/site-day over 250 days/yr from
or 2.0E+2 kg/yr

to: IncinerationStandard Review Risk Assessment for P09-417

January 12, 2010 Page 33 of 47 from:

basis:

RELEASE TOTAL 4.0E+2 kg/yr - all sites

OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY Tot. # of workers exposed via assessed routes:

B

Dermal:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 34 of 47 STANDARD REVIEW ENGINEERING REPORT CBI: Yes

PMN: 09-0417

Processing:

Number of Sites/ Location:

Unknown Cus mer Sites
Days/yr:

Basis:

ENVIRONMENTAL RELEASES ESTIMATE SUMMARY IRER Note: The daily releases listed for any source below may coincide with daily releases from the other sources to the same

medium.

Incineration or Landfill Output: 1.3E-3 kg/site-day over 250 days/yr from
or 3.1E-1 kg/yr

to: Incineration or land

from:

basis:

Land or water Output 2: 5.3E-3 kg/site-day over 250 days/yr from
or 1.3E+0 kg/yr

to: Land or water

from:

basis:

.

RELEASE TOTAL 1.6E+0 kg/yr - all sites

OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY Tot. # of workers exposed via assessed routes:

Basis:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 35 of 47 Exposure to Particulate in Coating Output: negligible over 250 days per year Number of workers (all sites) with inhalation exposure:

Basis:

Dermal:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 36 of 47 STANDARD REVIEW ENGINEERING REPORT CBI: Yes

PMN: 09-0417

**Use:**

Number of Sites/ Location:

Unknown Customer Sites
Days/yr: 250 Basis: Generic scenario for coating application in the furniture industry.

Process Description:

ENVIRONMENTAL RELEASES ESTIMATE SUMMARY IRER Note: The daily releases listed for any source below may coincide with daily releases from the other sources to the same

medium.

Incineration or Landfill Output: 1.3E-3 kg/site-day over 250 days/yr from
or 1.9E+0 kg/yr

to: Incineration or land

from:

basis:

Land or water Output: 8.3E-4 kg/site-day over 250 days/yr from
or 1.3E+0 kg/yr

to: Land or water

from:

basis:

Land or incineration Output: 2.4E-2 kg/site-day over 250 days/yr from
Or 3.9E+1 kg/yr

To: land or incineration

From:

B

RELEASE TOTAL 4.2E+1 kg/yr - all sites

OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY Tot. # of workers exposed via assessed routes:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 37 of 47 Basis:

Dermal:Standard Review Risk Assessment for P09-417

January 12, 2010 Page 38 of 47 CBI: Yes

MEMORANDUM of CBI TELEPHONE CONVERSATION

CALL BY: Anthony Gaglione Organization: ERG

CALL TO: Michelle B. Walker

Organization: Morris, Manning & Martin, LLP

Date: 03/11/2009

Time: 10:30 AM

Phone:

Concerning what TSCA CBI?

LOREX: 09-0004

CBI: Yes

MEMORANDUM of CBI TELEPHONE CONVERSATION

CALL BY: Anthony Gaglione Organization: ERG

CALL TO: Michelle Walker, Esq

Organization: Morris, Manning & Martin, LLPStandard Review Risk Assessment for P09-417

January 12, 2010 Page 39 of 47 Date: 03/16/2009

Time: 9:30 AM

Phone:

Concerning what TSCA CBI?

LOREX: 09-0004Standard Review Risk Assessment for P09-417

January 12, 2010 Page 40 of 47 NANOMATERIAL STANDARD EX POSURE REPORT

X-09-0004 (since Re-designated P09-417) Date 3/18/09

Assessor: Cinalli

Production Volume:

USE: Plastics additive to improve electrical , thermal and/or mechanical properties.

OTHER USES:

Chemical Name: Multi-walled carbon nanotubes

Fate Assessment :

Due to the novel nature of nanomaterials, it is not possible at this time to make assumptions about their behavior in th e environment withou t the collection of physicochemical (p-chem) and fate data. The p- chem properties which seem most important

for fate assessment are: surface reactivity, aggregation/agglomeration, physical form, particle size distribution, surface area solubility, disp ersability, shape, adsorption tendency and surface charge porosity.

These p-chem properties are novel to nanom aterials and are not estimated by our current collection of fate models, EPI Suite. Therefore, specific data on the actual behavior

of the nanomaterial in waste water treatment plants (e.g., bi odegradation, sorption to sludge, volatilization, etc.) and drinki ng water treatment plants (e .g., effect of chlorination, oxygenation, etc.) are needed to determine removal rates. Add itionally, data are needed to assess the potential for ground water migration. Testing methods typically used for these parameters (e.g., ready biodegradation test, poro us pot, etc.) may or may not apply. If the

amount of the nanomaterial released is of concern, EAB recommends that the submitter evaluate the current OPPT guide lines for fate testing and then submit fate testing protocols based on their specific knowledge of the nanom aterial to the EAB’s fate experts for theirStandard Review Risk Assessment for P09-417

January 12, 2010 Page 41 of 47 review prior to the actual testing. It is possi ble that after se veral nanomaterials have gone through p-chem and fate testing, that models in EPI Suite could be validated for use, or, more likely, a new fate model or models could be developed to estimate the fate of a new

nanomaterial in the environment.

General Population and Environmental Exposure

A qualitative evaluation of the releases estimated by CEB indicates that there is some potential for exposure to the genera l population and the environment from water, landfill

and/or incineration releases as well as fugitive air releases . Due to the novel nature of this PMN chemical it is not possible to quantify the exposure from these release scenarios. Human inhalation, ingestion and derm al exposure may result from the water, landfill, incineration and fugitive releases.

It is not possible at this time to quantify th e exposure due to the uncertainty surrounding the

environmental fate of nanomaterials in wate r, air, incineration and landfill, and the uncertainty of applying existing fate and air dispersion models that were developed based on

chemicals that are not nanomaterials. It is recommended that the submitter work with EPA engineers, fate experts and exposure assessors to develop chemical-specific testing for this

PMN chemical.

Specific data needs from the submitter are summarized below:

Identify all releases and their media of release.

Questions for incineration releases: Provide information to CEB e ngineer on: What type of control technology is used for th e incineration releases? What is its removal efficiency for the PMN substance? Are there any monitoring data available that demonstrate this efficiency? Provide data. Information to be provided to the EAB assessor: Are there any monitoring data available dow nwind of the incineration releases? Provide data.

Questions for air (fugitive releases) provide information to CEB e ngineer on: What type of control technology is used for the fugitive releases? What is its removal efficiency for the PMN substance? Are there any monitoring data available that demonstrate this efficiency? Provide data. Information to be provided to the EAB assessor: Are there any monitoring

data available downwind of the f ugitive releases? Provide data.

Questions for water releases : If the facility the PMN substa nce is being release from is a direct discharger, is the waste water discharged directly into the stream or into a on-site treatment plant? If it is discharged into an on-site treatment plant, what is the treatment method, how much of the PMN substance is rem oved during treatment, where is the stream located, and are there an y monitoring data to determine th e amount released? Provide data.

If the waste water is being released into a Publicly Owned Treatment Works (POTW), how does the PMN substance behave during the vari ous treatment steps ty pical of POTWs (e.g., flocculation, activated sludge, filtration, etc.)? How much of the PMN chemical is removedStandard Review Risk Assessment for P09-417

January 12, 2010 Page 42 of 47 during treatment? What is the mechanism of removal (e.g., adsorption into the sludge, biodegradation, volatilation, etc.)? What test methodologies were used to determine the answer to the above questi ons? Also, where is the PO TW located? Provide data.

Questions for landfill releases: What type of landfill will the PMN substance be placed in? What is the potential for migration of the PM N substance to the ground water? What testing data are available to support the migration po tential of the PMN substance? Provide data.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 43 of 47 Summary Economic Analysis

For Standard Review of PMN P-09-417 Reviewer: Kristen Loughery

I. BACKGROUND

A. Submitter: Nanocyl Corporation

B. Chemical Name:

C. Generic Name: MWCT, specialty synthetic graphite

D. Trade Name: Series NC 7000

E. CAS Number: None

F. Use(s): Additive to improve electrical, thermal, and/or mechanical properties of thermoplastic, thermoset, and coating materials.

II. MARKET ANALYSIS

A. Intended Uses

The PMN states that 100% of the PMN subs tance will be used in production as an additive to improve electrical , thermal, and/or mechanical properties of thermoplastic, thermoset, and coating materials.

According to the PMN, the end uses for CNTs are conductive pl astics, structural composite materials, flat-panel displays, ga s storage, electronics, radar-absorbing coating, technical textiles, ultra-capacitors, AFM tip s, batteries, biosensors, and fibers.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 44 of 47 The PMN substance can be used in the fo llowing industries: electronics, automotive, aeronautic, construction, sports, ma rine, foams and wires and cables. In the electronics sector,

the PMN substance can be used in semiconductor packaging, hard disk dr ives, and IC test and burn sockets. In the automotive sector, the PMN substance can be used in fuel system line components, fenders, mirror housings, and door handles. In the aeronau tics sector, the PMN substance can be used as epoxy composites and flame retardant coatings . In the construction sector, the PMN substance can be used as pr otection for construction substrates including metal, concrete, wood, plaster, and fiberboard. In the sports sector, the PMN substance can be used to make bike frames, hockey sticks, tennis rackets, golf shafts, and skis. In the marine sector, the PMN substance can be used to make masts for sailing vessels for improved mechanical durability and as antifouling paints to prevent waterborne organisms from adhering to the coating. The PMN substance is us ed in flexible and rigid foams and wires and

cables as a flame retardant.

B. Submitter

The PMN was submitted by Nanocyl. Nanocyl’s current plans are to import the PMN substance from the Nanocyl facility in Belgiu m directly to sites not controlled by Nanocyl. There will be no manufacturing or processing of the substance in any Nanocyl-controlled U.S. facility.

C. Substitutes

According to the submitter, the PMN subs tance is a substitute for carbon black and chopped carbon fibers. The CNTs are not directly replacing any substance. Compared to existing toxic marine coatings, Biocyl does not co ntain any solvent, biocide, or heavy metal. The PMN substance can be incorporated in ther moplastics as substitutes for old metallicmade auto parts. The PMN substance can also be a substitute for halogen and halogen-free

flame retardants.

D. Benefits of the PMN Material

According to the PMN, the PMN substance has a lower loading needed to reach a given resistivity in clean room devices, therefor e minimizing the contaminants in micro chips. The electrical conductivity can be controlled and there is no mo re risk of hot spots on the

surface of sockets. The PMN substance has high electrical conductiv ity and mechanicalStandard Review Risk Assessment for P09-417

January 12, 2010 Page 45 of 47 properties, decreased weight, a nd improved strength, shelf life, and antistatic properties. It also provides flame retardant protection of app lications such as tanks and exhaust parts.

Telephone Log – PMN P-09-417

DATE: July 20, 2009

EPA STAFF: Kristen Loughery

RESPONDENT: Richard Jourdenais 202-828-8992

The EPA staff member contacted the s ubmitter’s technical contact to request information concerning the chemicals described in the PMN to complete the economic report

for the standard review. The conversation ha s been paraphrased for brevity and clarity.

Q1: Can you confirm the information in the PMN that the PMN substance is going to be used as an additive to improve electrical, thermal, and/or mechanical properties of thermoplastic, thermoset, and coating materi als? Are there any other uses that the PMN substance could work in, even if you aren’t planning on them now?

Can you confirm that the PMN substance will be 100% for industrial use and that there are no

consumer or commercial uses for the substance?

What is the percent of the PMN s ubstance in the end formulation?

A1: Yes, I confirm the use information. The end uses for thermoplastic materials are the

I can

confirm that there are no consumer or commercial uses for the substance.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 46 of 47 Q2: W here/who will the PMN substance be imported from? Where will it be processed (site controlled by Nanocyl)? Can you confirm that Nanocyl has no other manufacturing facilities

in the United States?

A2: Nanocyl’s current plans are to import the PMN substance from the Nanocyl facility in Belgium directly to sites not controlled by Nanocyl. There will be no manufacturing or processing of the substance in any Nanocyl-controlled U.S. facility.

Q3: Are there any other locations in the U.S. that may manufacture the substance in the

future?

A3:

Q5: Do you know of any products that th e PMN substance is replacing?

A5: Carbon black and chopped carbon fibers. The CNTs are not directly replacing anything. Compared to existing toxic marine coatings, BI OCYL does not contain any solvent, biocide, or heavy metal.

Q6: Are there any additional benefits, besides the electrical, thermal, and mechanical properties improvements?

A6: I have included all of the bene fits in the PMN attachment.Standard Review Risk Assessment for P09-417

January 12, 2010 Page 47 of 47 Q10: Would you like to add any other information?

A10: No.

The EPA staff person thanked the submitter for his cooperation.