SUMMARY - Choose your language | Choisir une langueec.europa.eu/health/ph_risk/documents/tilmans.pdf · Submitted to DG SANCO by Dr. Harald Tillmanns PRO ... (e.g. like diamonds,

REACh

Contribution to the ongoing consultation on Risk Assessment of Nanotechnologies – A1.a Submitted to DG SANCO by Dr. Harald Tillmanns PRO-Coaching GmbH

© Copyright 2009, Dr. Harald Tillmanns PRO – Coaching GmbH, Idstein 1 Dr. Harald Tillmanns PRO-Coaching GmbH, Bahnofstr. 30; D-65510 Idstein -- Wiesbaden HRB 20712 / GF: Dr. Harald Tillmanns

SUMMARY

The objective of the studies is to find a reliable and science based definition to distinguish between bulk C-materials and nano scaled C-materials. Even if both substances are formed from the same element C, they can be differentiated by chemical and/or physical properties e.g. like structural pattern and especially by their formation mechanism. Objective is to separate and focus the obligation of evaluation on those substances which need to be studied on detail due to their intrinsic hazardous properties. Substances, even build up out of the same elements may significantly differ in there potential intrinsic properties and those which are proofed to be inert having no intrinsic hazardous properties. To distinguish between bulk type materials and nano scaled materials is needed any way, because otherwise the results of the data evaluation can not be interpreted nor understood. Furthermore it will lead to a confusion, while the bulk C materials are showing no hazardous properties whereas the nano scaled C material might show certain hazardous properties. As tools can be used e.g. physical and /or chemical properties like x-ray pattern and/or the formation mechanism for the interpretation of the results of the evaluation. This study is focused on substances formed out of the element C manufactured in bulk form (minimal particle size 1 – 10 µm by technical milling) respectively in C nano scaled the particles (< 1 up to 100 (500) nm maximum by a frozen nucleation mechansm).

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. Due to the sufficient reliable differentiation by physical and/or chemical properties (e.g. like crystal / molecular structural orientation detectable by x-ray analysis) and/or formation mechanism they have to be evaluated and handled separately in respect to the obligations of the REACh regulations:

• Synthetic bulk C materials (All forms of synthetic diamond / coke / carbon / charcoal / graphite) should be included in Annex V due to their intrinsic non hazardous properties,

• Naturally occurring substances (e.g. like diamonds, carbon and graphite) are exempted already by the Annex V, whereas

• Nano scaled C-materials have to be evaluated separate probably under the umbrella of carbon black due to their similarity in properties and formation mechanism.

Remark: The EINECS # is not a suitable tool for separating and/or grouping substances, it is only a code saying that the substance is listed as an existing substance, regardsless of there properties. It can only be used like the CAS # for identification) All studies reported here, where mainly focused on different substances formed by the element C.

For most types of initially nano C materials are below the threshold limit of 1 t/a in Europe and therefore not included in any obligations of REACh,

The volumes > 1 t/a, covered by REACh obligations, are carbon-black and nano tubes of carbon and fullerene

Whether these tools are applicable for other substances needs further studies, but for some of them (e.g. TiO2) a frozen nucleation process in a solution is described in literature.

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Conclusion

The different substances should be grouped, where possible, so that read-across principles can be used, following the scheme • carbon materials initially forming nano scaled particles (fullerene, C-nanotubes, carbon black, graphene foam) and • carbon material initially forming bulk scaled particles (diamond, carbon, coke, graphite) while being manufactured or naturally formed have different structural orientation (by x-ray) ------------------------------------------------------------------------------------------------------------------------- The bulk scaled carbon materials could be separated further in • mono-constituent substance - synthetic processed materials (diamond / coke- (petroleum / coaltar / coaltarpitch) / coke calcined / charcoal / carbon / graphite) and • mono- or multi constituent substance - naturally sourced materials (diamond / carbon (e.g. coke coal / anthracite / charcoal ?) / natural graphite) All bulk C – substances can be differentiated e.g. by x-ray analysis from the nano-scaled C-substances as well as by there formation mechanism and the intrinsic properties. ------------------------------------------------------------------------------------------------------------------------- A grouping of C substances by a C – nano C substances manufacturer is published and separates between diamond / graphite / fullerene and nano tubes - see next table.

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Several types of carbon from the point of view of a C-nano tube manufacturer

Diamond, a transparent mineral Chemical bonds between atoms are strong, and the tetrahedral symmetry is that of a dense and isotropic material. It is an electrical insulator, and the best refractory and thermal conductor known. Graphite, a black and friable mineral I ts structure consists of layers stacked together, each formed of regular hexagons of carbon atoms. This structure is 1/3rd weaker than that of diamond, making graphite an anisotropic and virtually two-dimensional solid. The layers are connected together by weak forces, and slip easily over one another. It is a semi-metal within the layer, with little conductivity in the other direction. Fullerene, or Buckminsterfullerene This molecule consists of 60 carbon atoms placed at the top of a regular polyhedron whose sides are hexagons or pentagons. Fullerene is electrophilic. It features high resistivity (approximately 1014 O/cm). Fullerene has a few applications, including microporous filters, sample supports for electronic microscopes, lubricants, etc. Carbon nanotubes Carbon nanotubes are a closed pipe-shaped material consisting of crystallized carbon. The length of the nanotubes can reach several microns, while their diameter ranges from 1 nm to 60 nm. The nanotube is represented by a graphene sheet wrapped or coiled based on a reference axis and direction. The helix angle (helicity) is variable, ranging from 0° to 30°. Nanotubes are closed by distortion of the hexagons, and by the introduction of pentagons in the nanotube structure. There are several types of nanotubes. Nanotubes are structured into single walls (Single Wall Nano Tubes, SWNTs) or multi

walls (Multi Wall Nano Tubes, MWNTs). The tubes nest within one another, with the distance between the walls close to the distance between two graphite planes (0.34 nm). Both structures are the result of different synthesis conditions. Reference: http://www.arkema.com/sites/group/en/products/spotlight/nanotubes1.page

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In the past I send already several contributions on the discussion of carbon respectively graphite bulk materials and the differences in structure of bulk C-substances and the significant different structure e.g. of nano-scaled C-materials like e.g. fullerens / nanotubes / graphene / graphene foam and others. (see up dated attachement)

A more detailed table of structural orientation is given in the next diagram.

Reference: Hill, J. W., and Petrucci, R. H., General Chemistry, 3rd edition, Prentice Hall, NJ, (2002)

Crystal structures of the different allotropes of carbon. (Left to right)Three-dimensional diamond and graphite (3D); two-dimensionalgraphene (2D); onedimensional nanotubes (1D); and zero-dimensionalbuckyballs (0D). (Adapted and reprinted with permission from66. © 2002 Prentice Hall.)

Reference: Hill, J. W., and Petrucci, R. H., General Chemistry, 3rd edition, Prentice Hall, NJ, (2002)

Crystal structures of the different allotropes of carbon. (Left to right)Three-dimensional diamond and graphite (3D); two-dimensionalgraphene (2D); onedimensional nanotubes (1D); and zero-dimensionalbuckyballs (0D). (Adapted and reprinted with permission from66. © 2002 Prentice Hall.)

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New investigations on further studies on the structure of the different types of C-materials showed that this can be proofed e.g. by x-ray analysis:

Substance Isotropy %sp? Symmetry3D Diamand : La = Lb = Lc sp3 tetrahedral3D Glassy carbon / Carbon Foam sp2<sp33D Isotropic - / Regular Coke sp2~sp33D Needle Coke / techn graphite sp2>sp33D Graphite : La = Lb <> Lc sp2 regular hexagons 2D Graphene : La = Lb sp2 regular hexagons 1D? Nanotubes : Lb <> La = Lc sp2 hexagons, (+pentagons)0D Fullerene : La = Lb = Lc sp2 hexagons+pentagons

Lc

La

Lb

Substance Isotropy %sp? Symmetry3D Diamand : La = Lb = Lc sp3 tetrahedral3D Glassy carbon / Carbon Foam sp2<sp33D Isotropic - / Regular Coke sp2~sp33D Needle Coke / techn graphite sp2>sp33D Graphite : La = Lb <> Lc sp2 regular hexagons 2D Graphene : La = Lb sp2 regular hexagons 1D? Nanotubes : Lb <> La = Lc sp2 hexagons, (+pentagons)0D Fullerene : La = Lb = Lc sp2 hexagons+pentagons

Lc

La

Lb

Lc

La

Lb

Lc

La

Lb

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• graphite is a stack of more or less perfect plane layers, 3 dimensional structred where the orientation

in the direction La = Lb are the same and may only differ in there extension. The orientation in Lc is defined by the number of stacked layers and an average interlayer distance of 3,35 up to < 3,44 Angstroem. Which can be characterised by x-ray diffraction pattern.

• carbon or amorphous respectively isotropic or glassy oriented carbons can be described also by a 3 dimensional structure with an average interlayer distance greater than 3,44 Angstreom. The perfect isotropic (-structure is called diamond. therefore all natural respectively synthetic carbons respectively graphite materials are located somewhere between a single crystal graphite structure and a diamond structure.

The structure of so called bulk carbons / graphite differ clearly and detectable by structural key data from so-called nanoscaled C-substances / molecules . Here a few e.g.

• fullerene are isotropic ball like structure of single or multilayer structure with equal structure orientation La=Lb=Lc

• nanotubes are anisotropic structure of concentric tubes with an orientation of La=Lc and a different orientation in Lb varying in the extension.

• graphene and graphene foam exist of mono layer element with LA=Lb and Le=1 This demonstrates that bulk C – substances e.g. like diamond / carbon / coke / charcoal / graphite and nano scaled C – substances e.g. like grapheme / fullerene / C – nanotubes (both single and multi walled) / and carbon black have defined different structural orientation and formation mechanism explained on detail in the following diagrams.

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DiamondNaturalSynthetic

Solid state processout of graphiteat ultra high -pressure,-temperature

GraphiteNaturalSynthetic

Macro-,Micro-granularorsingle crystal,

Solid state process outof pre-orientedsolid carbon byheat treatment

Solid carbon(Natural ?)Synthetic

Glassy carbon Carbon foam (solid shapes)Isotropic cokeRegular cokeNeedle coke

Liquid phase or solid state process out ofHydrocarbons byheat treatment

Graphene:

Synthetic

Single layer,graphene foam(agglomerate ofsingle layers)

Only by gas- / vapour- phase catalytic metal surface nucleation

Carbon black Nano-C

Synthetic Synthetic

Carbon black Nanotubes, Fullerene, (Single walled,Multi walled)Nano-C others

Only by gas- / vapour- phase nucleation process.

Only gas- / vapour- phase catalytic metal surface nucleation

Bulk carbon / graphite > 1 -10µm Nano - C < 1 – 100 nm (initial particle size)

Technical manufacturing processes / Formation mechanism


Solid state processout of graphiteat ultra high -pressure,-temperature



Solid state process outof pre-orientedsolid carbon byheat treatment



Liquid phase or solid state process out ofHydrocarbons byheat treatment

Graphene:

Synthetic


Only by gas- / vapour- phase catalytic metal surface nucleation

Carbon black Nano-C

Synthetic Synthetic


Only by gas- / vapour- phase nucleation process.

Only gas- / vapour- phase catalytic metal surface nucleation


Technical manufacturing processes / Formation mechanism

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Graphene:

Synthetic



Particle size limitations based on technical manufacturing processes

A mechanical down sizing of bulk C materials by

technical means of grinding and milling is only possible down to

minimal 1 to 10 µm

The mechanism to form nano scaled C materials is basically different .

Nano C-particles, in an initially size range of < 1 to 100 nm are only formed by nucleation.Particles up to 500 nm are formed by agglomeration

Carbon black Nano-C

Synthetic Synthetic







Graphene:

Synthetic



Particle size limitations based on technical manufacturing processes

A mechanical down sizing of bulk C materials by

technical means of grinding and milling is only possible down to

minimal 1 to 10 µm

The mechanism to form nano scaled C materials is basically different .

Nano C-particles, in an initially size range of < 1 to 100 nm are only formed by nucleation.Particles up to 500 nm are formed by agglomeration

Carbon black Nano-C

Synthetic Synthetic


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Proposal for including in Annex V or substance grouping according to REACh

Bulk carbon and graphite substances are or should be included in Annex V. due to the fact that they structural orientation (e.g. x-ray diffraction) are different nd they

have no intrinsic hazardous properties as proofed by known medical applications and biocompatibility

The nano scaled C substances don’t have a tetrahedral (diamond–sp2) hexagonal / rhombohedral (graphite-sp3) structure.

Nano scaled C substances can be differentiated from bulk-C (diamond / carbon / graphite) by there structural orientation (e.g. x-ray

pattern). Any assumed hazardous properties are nano size related

Carbon black Nano-C

Synthetic Synthetic


Graphene:

Synthetic









Bulk carbon and graphite substances are or should be included in Annex V. due to the fact that they structural orientation (e.g. x-ray diffraction) are different nd they

have no intrinsic hazardous properties as proofed by known medical applications and biocompatibility

The nano scaled C substances don’t have a tetrahedral (diamond–sp2) hexagonal / rhombohedral (graphite-sp3) structure.

Nano scaled C substances can be differentiated from bulk-C (diamond / carbon / graphite) by there structural orientation (e.g. x-ray

pattern). Any assumed hazardous properties are nano size related

Carbon black Nano-C

Synthetic Synthetic


Graphene:

Synthetic


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Bulk carbon and graphite substances should be included in Annex V

Natural graphite is a mineral and exempted - Annex V

Synthetic bulk-carbon / -graphite should be exempted and has to be added to - Annex V equivalent to coke

Nano scaled C substances can be differentiated from bulk-C .Any assumed hazardous properties are nano size or molecular structure

related. Might be grouped, according to the principle of sameness with

carbon black. QSAR (carbon black / nano-C) might be applied.

This needs further investigations

Carbon black Nano-C

Synthetic Synthetic


Graphene:

Synthetic









Bulk carbon and graphite substances should be included in Annex V

Natural graphite is a mineral and exempted - Annex V

Synthetic bulk-carbon / -graphite should be exempted and has to be added to - Annex V equivalent to coke

Nano scaled C substances can be differentiated from bulk-C .Any assumed hazardous properties are nano size or molecular structure

related. Might be grouped, according to the principle of sameness with

carbon black. QSAR (carbon black / nano-C) might be applied.

This needs further investigations

Carbon black Nano-C

Synthetic Synthetic


Graphene:

Synthetic


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Spectral data, crystalline structures (e.g. detectable by X-ray diffraction as well as different formation mechanism are applicable as identifiers according to RIP 3.10

4.2.3.2 Identifiers These substances are identified and named according to the rules for mono- constituent substances (see Chapter 4.2.2) or multi-constituent substances (see Chapter 4.2.3). The other specific main identification parameters to be added depend on the substance. Examples of other main identifiers can be elemental composition with spectral data, the crystalline structure as revealed by X-ray diffraction (XRD), Infra Red absorption peaks, swelling index, cation exchange capacity or other physical and chemical properties.

RIP 3.10 Guidance on substances identification -- UVCB

4.2.3 Substances of defined chemical composition and other main identifiers Some substances (e.g. inorganic minerals) which can be identified by their chemical composition need to be specified by additional identifiers to get their own substance identification. These substances can be either mono-constituent substances or multi-constituent substances, but need, in addition to the substance identification parameters described in the previous chapters, other main identifiers to record the substance identity unequivocally.

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Modelle zum Aufbau von C-Nanomaterial aus Graphene-Elementen und deren mögliche

Verwandschaft zu Ruißen

An HPLC trace showing fullerenes found in carbon soot. Many fullerenes have now been discovered in carbon soot, uncovered by electron microscopy, including tubes of carbon many thousands of times long as they are wide.

Modelle zum Aufbau von C-Nanomaterial aus Graphene-Elementen und deren mögliche

Verwandschaft zu Ruißen

An HPLC trace showing fullerenes found in carbon soot. Many fullerenes have now been discovered in carbon soot, uncovered by electron microscopy, including tubes of carbon many thousands of times long as they are wide.

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For all other types of nanoscale C-substances comparable differentiations in the orientation can be described and proofed by x-ray measurement. Considering the differences which can be detected by X-ray measurement leads clearly to the result that all types of nanoscaled C-substances can and have to be evaluated as independent, individual substance. Newer results show that typical structural characteristics of nanosclcd C-substances are found in low concentrations in carbon black. Further structural investigations (e.g. X-ray have to proof where nanoscaled C-substance may grouped with carbon black. A further indication that nanoscaled C-substances have to separated in the grouping from graphite respectively from carbon are:

• bulk type carbon and graphite substances are formed in a liquid or solid phase thermal decomposition process and can be mechanically reduced by mechanical means in grain size down to min. 1 to 10 µm

• C - nanoscaled substances are formed by a frozen nucleation process in respectively out of the gas or vapour phase or on a catalytically initiated nucleation process building defined molecular structure ”molecules” of a similar atom orientation. Freezing the nucleation means stopping the growth of particles by quenching . C nano scaled substances including single - and multi walled nanotubes and fullerens vary in their molecular weights and in their particle size from < 1nm up to max 100 nm. Larger sized particles ( up to ~ 500 nm) are generally formed by are agglomeration of initially formed nanoscaled particles of < 100 nm.

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Therefore based on x-ray structure studies a grouping of defined nanoscaled C-substances with bulk type carbon respectively graphite is not based on natural science facts. Bulk and nanoscaled C substances do not meet the demands of REACh definitions of an acceptable sameness. Both types of C-materials and have to be evaluated and handled separately as individual substances according the REACh regulation.. The differents of X-ray pattern and diffraction to distinguish between typically bulk C – substances and nano scaled substances are demonstrated in the next two diagrams Probably it is acceptable to group the nano scaled C-substances with carbon-black Whether a comparable differentiation in structural and/ molecular characterisation for other materials e.g. TIO2 is applicable has to be investigated.

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Graphene:

Synthetic


X-ray pattern of typical bulk C substances

Carbon black Nano-C

Synthetic Synthetic

Ref.: Dr. H. Tillmanns, Ph. Thesis, 1970 –1975, Dissertation (1975)E. Fitzer, Funk, F. Rozploch 4th London Int. Carbon & Graphite Conf. (1974)




Graphene:

Synthetic


X-ray pattern of typical bulk C substances

Carbon black Nano-C

Synthetic Synthetic

Ref.: Dr. H. Tillmanns, Ph. Thesis, 1970 –1975, Dissertation (1975)E. Fitzer, Funk, F. Rozploch 4th London Int. Carbon & Graphite Conf. (1974)

Naturally occurring graphite Synthetic graphite

Amorphous carbon(poor graphitizing)

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Graphene:

Synthetic


X-ray pattern of typical nano scaled C substances

Carbon black Nano-C

Synthetic Synthetic

Ref.: (a) SWNT bundles <A. Thess et al. Science, 273, 483 (1996)>(b) MWNT’s <D. Reznik et al. Phys.Rev.B. 52, 116 (1995)>(c) Fullerene C60 <J. C. Scanlon et. Al., J. Phys. Chem. 97, 7138 (1993) (d) Fullerene soot <J. C. Scanlon et. Al., J. Phys. Chem. 97, 7138 (1993)

(a) (b) (c)

(d)




Graphene:

Synthetic


X-ray pattern of typical nano scaled C substances

Carbon black Nano-C

Synthetic Synthetic

Ref.: (a) SWNT bundles <A. Thess et al. Science, 273, 483 (1996)>(b) MWNT’s <D. Reznik et al. Phys.Rev.B. 52, 116 (1995)>(c) Fullerene C60 <J. C. Scanlon et. Al., J. Phys. Chem. 97, 7138 (1993) (d) Fullerene soot <J. C. Scanlon et. Al., J. Phys. Chem. 97, 7138 (1993)

(a) (b) (c)

(d)

(a) (b) (c)

(d)

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ATTACHMENT

D1.a Contribution to a final consultation on substances of Annex IV and Annex V of the REACh Regulation, respectively on the Draft Guidance on Annex V

Submitted to DG ENTR / DG ENV /ECHA) by Dr. Harald Tillmanns PRO-Coaching GmbH

D1.a Contribution to a final consultation on substances of Annex IV and Annex V of the REACh Regulation, respectively on the Draft Guidance on Annex V Submitted to DG ENTR / DG ENV /ECHA) by Dr. Harald Tillmanns PRO-Coaching GmbH -


SUMMARY REGULATION (EC) No 1907/2006 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL Article 2 Application 7. The following shall be exempted from Titles II (REGISTRATION OF SUBSTANCES) , V (DOWNSTREAM USERS) and VI (EVALUATION):

(a) substances included in Annex IV, as sufficient information is known about these substances that they are considered to cause minimum risk because of their known intrinsic, none hazardous properties; (b) substances covered by Annex V, as registration is deemed inappropriate or unnecessary for these substances and their exemption from these Titles does not prejudice the objectives of this Regulation;

----------------------------------------- Substance Name CAS# EINECS# Considered bulk forms of Carbon materials (defined i.e. X-ray pattern and the formation mechanism in liquid phase / solid state) Diamond *) 7782-40-3 231-953-2 Graphite 7782-42-5 231-955-3 Carbon 7440-44-0 231-153-3 Coke (coal) **) 65996-77-2 266-010-4 Coke (petroleum), calcined 64743-05-1 265-210-9 Considered nano forms of Carbon materials (defined i.e. X-ray pattern and the formation mechanism frozen nucleation) Carbon black 1333-86-4 215-609-9 Carbon nano materials as such i.e. Fullerene, Nanotubes, Graphene foam

99685-96-8 (Fullerene)

n.a.

*) Diamond as such is not considered here on detail. **) Including i.e. Charcoal, Lignite Coke



Proposal for a schematic classification of carbon materials according to the crystal structure and initially manufuctered particle size (bulk scaled / nano scaled) and the mechanism of formation

*) It might by suitable to identify the bulk, natural carbon material as mono-constiuent or as multi-constituents or as naturally occurring substances. in accordance with RIP 3.10 Figure 4.1 and section 4.2.3; containing inorganic constituents, i.e. like silca (quartz) or other minerals in excess over 20 %

Name CAS# EINECS# Annex

Diamond 7782-40-3 231-953-2Coke (petroleum), calcined64743-05-1 265-210-9

Carbon 7440-44-0 231-153-3Graphite 7782-42-5 231-955-3

Diamond 7782-40-3 231-953-2 IVCoke (coal) *) 65996-77-2 266-010-4 IV

CarbonGraphite *) 7782-42-5 231-955-3 IV

Carbon black 1333-86-4 215-609-9 ?

Fullerene 99685-96-8 n.a. ?

Manufactured Inital Particle Size

Diamond (sp3)

Graphite (sp2)

Carbon black (sp3 - sp2)

Syntheticcarbon material,

mono constituentsubstance

Naturalcarbon materialmono- or multi-

constituent substance

Intermediate C (sp3 - sp2)

Proposal for a schematic classification of carbon materials C-Group (structure)

Initialbulk

carbon material

Initial nano scaled

carbon material



Carbonmaterial


Diamond (sp3)

Graphite (sp2)

i.e. Fullerene, Nanotubes

IV



The objective of the comments is to support the experts in finding a reliable and practible conclusion in grouping and read-across approach for the different forms of solid carbon materials and to distinguish between bulk scaled and nano scaled substances in respect to include carbon & graphite (synthetic and natural) in Annex V and to register nano scaled carbons separately under the umbrella (sub grouping

with) carbon black.

Conclusion The different substances should be grouped, where possible, so that read-across principles can be used, following the scheme

• carbon materials initially forming nano scaled particles (fullerene, C-nanotubes, carbon black) and • carbon material initially forming bulk scaled particles (diamond, carbon, coke, graphite)

while being manufactured or naturally occurring. -------------------------------------------------------------------------------------------------------------------------------------- The bulk scaled carbon materials could be separated further in

• mono-constituent substance - synthetic processed materials (diamond / coke (petroleum) calcined / carbon / graphite) and

• mono- or multi constituent substance - naturally sourced materials (diamond / coke (coal) / natural graphite)

if the content of inorganic constituents, i.e. like silca (quartz) or other defined minerals exceed the impurity level or an individual evaluation of hazard properties of one of the constituent can not be neglected the substance can be classified as multi constituent substance. -------------------------------------------------------------------------------------------------------------------------------------



Sufficient information are known about all solid carbon containing substances that they are considered to cause minimum risk because of their intrinsic, non hazardous properties. Other forms of bulk carbon materials like “coke (petroleum) calcined”and “coke (coal)” and comparable forms show similar inherent inert properties like carbon and graphite. Therefore bulk carbon and graphite should be treated similar to coke and be exempted in Annex V. The only differences in carbon is the precursor (technical hydrocarbons i.e. like polymers and/or resins (cured and uncured) respectively natural forms of hydrocarbons i.e. like lignite / wood / nutshells). The precursor for graphite is a pre-oriented carbon or coke transferred only by high temperature treatment into more or less perfect layer structure of graphite Reported hazardous properties are only related to the presents of mineral constituents i.e. like silica (quartz) in naturally occurring substances like natural graphite (exempted in Annex V) and are not reported for any form of synthetic bulk carbon and graphite materials as such.

• All forms of bulk carbon materials as such should be grouped and be listed in Annex V due to their inherent inert properties of solid bulk carbon materials.

• Nano scaled structured C-substances can can be distinguished from the bulk form by crystal structure analysis (i.e. X-ray diffraction and there formation mechanism. All nano scaled forms of carbon needs to evaluated separately and might be handled as a separated sub-group of carbon black, due to the similarity in properties and formation mechanism.

--------------------------------------------------------------------------------------------------------------------------------------



The structure of nano scaled carbons i.e. like fullerene and C-nanotubes including multilayer C-nano materials are still distinct molecules in a wide variety of molecular weight, better comparable to individual primal particles of carbon black powders and their principles of formation are similar (frozen nucleation

i.e. in the gas or vapour- phase).

Therefore fullerenes and other C-nano materials should not be grouped with graphite, but with carbon black.

Ref.: http://de.wikipedia.org/wiki/Kohlenstoff and numerous links to all forms of carbon materials are available in wikipedia and citied literature Ref.: Numerous articles, MSDS and producer informations have been evaluated by Dr. H. Ti

Initial particle size while formed

0,1 1 10 100 1000 10000 100000 1000000

Nano Carbon

Carbon black

Bulk Carbon

Initial particle size [nm]Dr. H. Ti

DiamondCarbon

Coke (coal)Coke (petroleum), calcined

Graphite



Overview of information in the submission Additional information submitted Substance Ref. Effect on

evaluation Ref. Compliance …….

Value of endpoints Remarks submitted see references attached

Ref. # listed

Effects reported in

Carbon-C (CAS# 7440-44-0)

7.7 Water solubility IUCLID/ QSAR

Not soluble Sw: 22mg/L (25 deg C) 428.,49 mg/l (25 deg C, est)

In all C-related MSDS reporting: Insoluble / neclectable QSAR only very limited applicable

1) MSDS’s

Carbon-C 8.1 Skin irritation MSDS May cause mild irritation and redness

Carbon-C 8.2 Eye irritation May cause mild irritation and redness

Carbon-C 8.3 Skin sensitisation Expert judgement

Not anticipated to be sensitising

Carbon-C 8.4 Mutagenicity OECD Not genotoxic

Carbon-C 8.5 Acute toxicity OECD LD0 rat oral 8000-10000 mg/kg bw (carbon black)

No acute toxic effect reported. Graphite is used as pharma-ceutical / medical implant

2) Lit.

Carbon-C 8.6 Repeated dose toxicity

Carbon is used as pharmaceutical / medical implant / Very high biocompatibility

3) Lit

Carbon-C 8.9 Carcinogenicity) Carbon is not listed as carccinogen in IARC nor in IUCLID dataset nor in NTP, OSHA or ACGIH

4) MSDS

IARC – no NTP – no

Carbon-C

9.1 Aquatic toxicity Acute EC/LC50 > 1000 mg/l or Sw NOEC > 10 mg/l

Contradictive to: see position 8.5 + 8.6 + 8.9.1 see compliance of graphite

A more detailled evaluation of testing results shows no toxic effect but, only physical / mechanical impact Carbon is used in drinking water treatment

5) *)

Expert judgement

Carbon-C 9.2 Degradation No degradation in the environment Ancient carbon findings – unchanged

Carbon-C 9.3 Fate and behaviour in the environment

No impact on the environment Ancient carbon findings – no impact

Carbon-C 9.4 Effects on errestrial organisms

No impact on terrestical organisms Ancient carbon findings in the ground

6) Expert judgement



Overview of information in the submission Additional information submitted Substance Ref

. Effect on evaluation

Ref. Compliance ……. Value of endpoints

Remarks submitted see references attached

Ref. # listed

Effects reported in

Graphite-C (CAS# 7782-42-5)

7.7 Water solubility In all C-related MSDS reporting: Insoluble / neclectable 1) MSDS’s

Graphite-C 8.1 Skin irritation MSDS May cause mild irritation and redness Differs from graphite

Compliance shoul be the same as for carbon *)

Graphite-C 8.2 Eye irritation May cause mild irritation and redness Differs from graphite

Compliance shoul be the same as for carbon *)

Graphite-C 8.3 Skin sensitisation not anticipated to be sensitising Graphite-C 8.4 Mutagenicity

Expert judgement not anticipated to be sensitising

Graphite-C 8.5 Acute toxicity MSDS Dust is irritating to the respiratory tract

Inhalation

No acute toxic effect reported. Graphite is used as pharma-ceutical / medical implant

2) Lit

Graphite-C

8.6 Repeated dose toxicity

MSDS Prolonged inhalation of excessive dust may produce pulmonary disorders, Chronic inhalation exposure to natural graphite is associated with the development of pneumoconiosis

Graphite is used as pharmaceutical / medical implant Toxicity effect is related the quartz content if natural geaphite not to graphit itself. Synthetic graphite no effect

3) **)

Lit..

Graphite-C 8.9 Carcinogenicity MSDS *) IARC : Group 1 carcinogen, NTP suspect carcinogen

Graphite is not listed in IARC nor in IUCLID dataset nor in NTP, OSHA or ACGIH

4) **)

MSDS IARC – no NTP – no



Overview of information in the submission Additional information submitted Substance Ref

. Effect on evaluation

Ref. Compliance ……. Value of endpoints

Remarks submitted see references attached

Ref. # listed

Effects reported in

Graphite-C 9.1 Aquatic toxicity Acute EC/LC50 > 1000 mg/l or Sw NOEC > 10 mg/l

Contradictive to: see position 7.7 + 8.5 + 8.6 + 8.9.1

A more detailled evaluation of testing results shows no toxic effect but, only physical / mechanical impact Carbon is used in drinking water treatment

0) 5)

Expert judgement

Graphite-C 9.2 Degradation No degradation in the environment Ancient carbon findings - unchanged

Graphite-C 9.3 Fate and behaviour in the environment

No impact on the environment Ancient carbon findings – no impact

Graphite-C 9.4 Effects on terrestrial organisms

No impact on terrestical organisms Ancient carbon findings in the ground

6) Expert judgement

Hazardous properties identified are *) possible related to content of quartz **) only related to quartz



0) General remarks No access to the references listed in the overview of information in the submission. No detailled crosscheck are possible. Contradictive statement of compliance, even if the values of endpointsare the same (see carbon & graphite)

1) Water solubility: Different forms of carbon materials are reported in all checked MSDS as insoluble or immiscible COLLOIDAL GRAPHITE: Solubility in Water IMMISCIBLE Ref.: http://www.setonresourcecenter.com/msds/docs/wcd00007/wcd0077c.htm <<CARBON>>/GRAPHITE GRADES :Solubility in Water INSOLUBLE Ref.: http://www.setonresourcecenter.com/dtSearch/dtisapi6.dll?cmd=getdoc&DocId=1297... Coke: SOLUBILITY IN WATER Not Soluble Ref.: MSDS Oxbow Calcining LLC Natural graphite: SOLUBILITY IN WATER Insoluble. Ref.: MSDS WEST SYSTEM® 423™ Graphite Powder.

2) Acute Toxicity: “This product (Coke) is nontoxic. The “nuisance dust” exposure values that are listed apply to any inert substance capable of producing airborne particulates. Excessive concentrations of calcined petroleum coke may reduce visibility, cause unpleasant deposits in the eye, ears, and nasal passages, or irritate the skin or mucous membranes by mechanical means. However, normal workplace exposure has not been determined to cause a significant health effect. Calcined petroleum coke, as with many petroleum products, may cause minor skin, eye, or lung irritation, but good hygienic practices can minimize these effects.” Ref.: www.oxbow.com/text/MSDS_COKE.pdf

3) Biocompatibility of carbon and graphite:. “Carbon Particles (CP) - Diamond Powder Particles (DPP) and Graphite Particles(GP) have been examined on molecular, macroscopic and clinical level. ……….. In vivo examinations with Carbon Particles (GP & GP) proved the biocompatibility with living organism ( the contact reaction with peritoneum) and these results indicate that only DPP (Remark: probably related to surface structure. Dr.H.Ti) is bioactive…. Ref.: http://www.science24.com/paper/905 The feasibilty of an organic mechanical attachment between cortical bone tissues and elemental carbon has been successfully demonstrated. Ref.: Elemental carbon as a biomaterial Jim Benson Journal of Biomedical Materials Research Volume 5, Issue 6 , Pages 41 – 47



4) Carcinogenity: Carbon nor Graphite or high temperature annealed coke are not listed as carcinogen in the actual IARC Monographs Ref.: http://monographs.iarc.fr/ENG/Classification/index.php *) “Synthetic Graphite : None of the components present in this material at concentrations equal or greater than 0.1% is listed by IARC, NTP, OSHA or ACGIH as a carcinogen.” Ref.: http://www.timcal.com/SCOPI/Group/timcal/tim01cor.nsf/Timcal-frm-Download?readForm&lang=wo&aliasdoc=902020 „ Natural Graphite: Natural Graphite may contain impurities of 1 - 3 % crystalline silica (quartz, CAS 14808-60-7) which is listed by IARC as Group 1 carcinogen and by ACGIH as A2 (suspected human carcinogen).” Ref.: http://www.timcal.com/SCOPI/Group/timcal/tim01cor.nsf/Timcal-frm-Download?readForm&lang=wo&aliasdoc=902020 Natural Graphite - Carcinogenicity: For Silica, Crystalline: Content 0 – 4 % - Cristobalite (14464-46-1), quartz (14808-60-7), and tridymite (15468-32-3) are listed by NTP as known to be a human carcinogen. - NIOSH considers cristobalite, tridymite, quartz, and tripoli (1317-95-9) to be potential occupational carcinogens. --------\Cancer Lists\------------------------------------------------------ ---NTP Carcinogen--- Ingredient Known Anticipated IARC Category ------------------------------------ ----- ----------- ------------- Graphite (7782-42-5) No No None Quartz (14808-60-7) Yes No 1 Ref.: http://www.jtbaker.com/msds/englishhtml/g8122.htm “Calcined Petroleum Coke: Is product listed as Carcinogen or Potential Carcinogen by: NTP? No IARC? No OSHA? No” Ref.: www.oxbow.com/text/MSDS_COKE.pdf “Coke: None of the components present in this material at concentrations equal or greater than 0.1% are listed by IARC(Group 1,2A or 2B), NTP, OSHA or ACGIH as a carcinogen. Ref.: http://www.timcal.com/SCOPI/Group/timcal/tim01cor.nsf/Timcal-frm-Download?readForm&lang=wo&aliasdoc=902020



5) Aquatic Toxicity: “Arsenic Removal from Drinking Water by Coagulation/Filtrationand Lime Softening Plants” Flocculatio:. Flocculation of alum hydroxide and various contaminants, including arsenic, occurs during this treatment process. During late summer, powdered activated carbon (PAC) ma ybe added for taste and odor control. Ref http://www.epa.gov/nrmrl/pubs/600r0006360/0r Chapter 4 : Removal of Organics and Inorganics by Activated Carbon Ref.: Chemistry of Water Treatment / Samuel Denton Faust , Osman M. Aly / CRC PRESS 1998

6) Degradation / Fate and behaviour in the environment / Effects on terrestrial organisms Historical, ancient findings of carbon materials i.e. like fire places or burned / carbonized wood show no degradation, no effect on the environment are observed, no impact on terrestial organisms could be detected. Ref.: Expert judgment

7) Meanwhile have additional investigations proofed that bulk C-materials and nano-scaled materials can be distinguished by their formation mechanism and by spectrographic and X-ray analysis (see attachment – SANCO consultation)



Three atomic bonds can be destinguished

• Diamond (sp3) *) • Graphite (sp2), with dislocated electrons • Organic triple-bonds (sp1) **)

*) Diamond as such are not considered here **) (sp1) bonds are not of any significant for solid carbon materials and not considered here. Two initially manufuctered of carbon materials according to particle size can be destinguished

• Bulk scaled carbon materials • Nano scaled carbon materials

(i.e.natural / synthetic)

(i.e.natural / synthetic)

Main AllotropesSubgroup of Allotropes

Element

Graphit (sp2)

amorphous C (sp3 - sp2)bulk sized C (sp3 - sp2)

nano scaled C (sp3 - sp2)

bulk sized C (sp2)

Examples

(i.e. glassy carbon / charcoal / activated carbon /coke (i.e. natural /

synthetic) and others)

(i.e.carbon black / soot / fullerene / C-nanotubes and others

Allotropes of carbon material

Diamond (sp3)

C-molecules (sp2 - sp3(?))

bulk sized C (sp3)

Carbonmaterial



Structural aspects bulk carbon materials

All solid carbon materials described here are close to exclusively structured by (sp3) and (sp2) bonds. A second major structural aspect to destinguish betwenn different carbon structure are the proportion of (sp3) and (sp2), the hights of the stacks without relevant defects and the avaraged basal layer distance, besides of the initially formed particle size while being produced.. The wide range of bulk carbon materials ( isotropic carbon i.e. glassy carbon, over amorphous carbon i.e. carbon char, coke, synthetic industrial baked carbon and highly anisotropic carbon like graphite,) can be desribed by percentage of by (sp3) and (sp2), a basal layer structure characterized by stackhights of basal layers and the avaraged distance of basal layers. All bulk carbon materials are characterized by a three dimensional structure initially formed as coarse grained substance. The different allotropes are formed by a variation in the percentage of by (sp3) and (sp2) bonds, but all of them show no hazardous properties, proofed by the pharmaceutical and medical applications due to the fact that thes have a very high biocompatibility. The basal layer stackhights varies from 4-10 for isotropic materials like glassy carbon up to serveral hundred layers i.e. graphite (natural and synthetic). The avaraged basal layer distance varies from upto sereval times of a 0,335 nm for isotropic materials down to 0,335 nm for graphite.

Highly isotropic carbon material like tetraedric amorphous carbon can be defined as such bulk carbon materials containing more than 70 % (sp3) bonds. The evaluation of properties of bulk carbon materials has to be restricted to the properties of the bulk carbon substance as such. Hazardous properties derived from other substances being a constituent or an impurity of the sysnthetic or natural carbon substance have to elavuated in separate risk assement restricted to this constituent i.e like silica/quartz in natural graphite.

Graphite Amorphous Carbon



Image Ref.: http://de.wikipedia.org/wiki/Kohlenstoff

Physcal Properties of C-Material f(structure)

1,E+00

1,E+03

1,E+06

1,E+09

1,E+12

1,E+15

1,E+18

0 500 1000 1500 2000 2500

thermal Conductivity {W/mK]

elec

tr.

Res

isti

vity

[µ

Om

]

Amorphous Carbon

Diamond

Graphite

Dr. H. Ti



Physical Properties of Graphite f(structure)

1,E+00

1,E+01

1,E+02

1,E+03

1,E+04

1 10 100 1000

thermal Conductivity {W/mK]

elec

tr.

Res

isti

vity

[µ

Om

]

Pyro-graphite

Graphite ab

Polycryst. graphite

Graphite c



Characteristics of Bulk Carbon - Crytallite Size

3,35

3,40

3,45

3,50

3,55

3,60

3,65

0 200 400 600 800 1000

Lc Stack height [A]

c/2

Lay

er d

ista

nce

[A

]

Diamond

Graphite

Dr. H. Ti

By Harry Marsh



Characteristics of Bulk Carbon - Crystallite Size

3,35

3,40

3,45

3,50

3,55

3,60

3,65

0 200 400 600 800 1000

La Layer size [A]

c/2

Lay

er d

ista

nce

[A

] Diamond

Graphite

Dr. H. Ti

By Harry Marsh



Proposal of schematic structuring bulk carbon materials (Dr. H. Ti)


Diamond 7782-40-3 231-953-2 IV

Carbon 7440-44-0 231-153-3 IVCoke (coal) 65996-77-2 266-010-4 IV

Coke (petroleum), calcined64743-05-1 265-210-9 IV

Graphite 7782-42-5 231-955-3 IV

C-Group (structure)

Initialbulk

carbon materialIntermediate C (sp3 - sp2)


Diamond (sp3)

Graphite (sp2)



Proposal of schematic structuring bulk carbon materials (Dr. H. Ti) If a separate grouping of natural and synthetic bulk carbon material is needed due to excessive content of inorganic mineral constituents.

*) It might by suitable to identify the bulk, natural carbon material as mono-constiuent or as multi-constituent. in accordance with RIP 3.10 Figure 4.1 and section 4.2.3; containing inorganic constituents, i.e. like silca (quartz) or other minerals exceeds 20 %


Diamond 7782-40-3 231-953-2Coke (petroleum), calcined64743-05-1 265-210-9

Carbon 7440-44-0 231-153-3Graphite 7782-42-5 231-955-3

Diamond 7782-40-3 231-953-2 IVCoke (coal) *) 65996-77-2 266-010-4 IV

CarbonGraphite *) 7782-42-5 231-955-3 IV


Intermediate C (sp3 - sp2)Intermediate C (sp3 - sp2)

Diamond (sp3)

Graphite (sp2)

C-Group (structure)

Initialbulk

carbon material


Diamond (sp3)

Graphite (sp2)

Syntheticcarbon material

Naturalcarbon material

IVIntermediate C (sp3 - sp2)



Structural aspects of nano scaled carbon materials

Comparision of particle size initially formed while manufacturing carbon black and nano materials like fullerene and nano-tubes Carbon black is build from very small, mostly spherical individual primal particles of approximately 10 – 300 nm. These indivdual particulates agglomarate to clusters up to several hunderd time in diameter. The properties of carbon black may differ significantly depending on the manufacturing process and especially on the formation- or final heat treatment- temperature. According to the grade individual properties assessments are needed.

Carbon black Image Ref.: http://de.wikipedia.org/wiki/Ru%C3%9F

Fullerene and nanotubes have only one basal layer forming in the first case a spherical and in the second case a tube having complete different properties than bulk graphite and being formed by more or less defined molecules. The diameter of the individual particles range from < 1 nm up to ~ 10 nm. For some applications multilayer nanomaterial can be formed, having a onoin like structure sometimes destribed as graphitic. The diameter of the individual particles range from ~ 10 nm up to ~ 200 nm.

Nanotubes Fullerene Image Ref.: http://de.wikipedia.org/wiki/Kohlenstoff A grouping with graphite is incorrect because some of determining properties of the graphite and the particle range are significantly different..



Comparable formation procedure of carbon black and nano material like fullerene or C-nanotubes

An HPLC trace showing fullerenes found in carbon soot. Many fullerenes have now been discovered in carbon soot, uncovered by electron microscopy, including tubes of carbon many thousands of times long as they are wide, with the same icosahedral structure as the fullerenes. These have diameters as small as 2nm. Carbon "onions" have also been discovered, and consist of carbon cages one inside the other rather like Russian dolls. These carbon particles have millions of atoms, and many have been observed with dozens of concentric shells. Hypothetical structures have been postulated for carbon cages consisting of not pentagonal and hexagonal rings (like C60), but heptagonal (7 membered) rings. Take the bell-jar off and scrape the glass surfaces clean, collect all the material. 10 % of the soot should be made up of C60 Ref.: http://www.ch.ic.ac.uk/local/projects/unwin/Fullerenes.html The structure and formation/growth mechanism of soot particles (carbon blacks) have recently been elucidated by TEM experiments, and this study led to a surprising conclusion that the primary particles of carbon blacks are highly defective multi-shell fullerenes. Ref.:‘Carbon Nanotechnology’, Dai, L. (Ed.), Chapt. 6, p. 127-151, Elsevier: Dordrecht, 2006.

Proposal of schematic structuring nano scaled carbon materials (Dr. H. Ti)


Carbon black 1333-86-4 215-609-9 ?

Fullerene 99685-96-8 n.a. ?


C-Group (structure)

Initial nano scaled

carbon material

Carbon black (sp3 - sp2)

i.e. Fullerene, Nanotubes



The structure of nano scaled carbons i.e. like fullerene and C-nanotubes including multilayer C-nano materials are still distinct molecules better comparable to individual primal particles of carbon black

powders and their principle of formation are similar.

Therefore all C-nano materials can not be grouped with carbon and/or graphite and have to be evaluated individually and as a separate substance.

Due to their similarity with carbon black is might the evaluated as an independent subgroup there-of. Ref.: http://de.wikipedia.org/wiki/Kohlenstoff and numerous links to all forms of carbon materials are available in wikipedia and citied literature Ref.: Numerous articles, MSDS and producer informations have been evaluated by Dr. H. Ti

Initial particle size while formed

0,1 1 10 100 1000 10000 100000 1000000

Nano Carbon

Carbon black

Bulk Carbon

Initial particle size [nm]Dr. H. Ti

Documents

SUMMARY - Choose your language | Choisir une langueec.europa.eu/health/ph_risk/documents/tilmans.pdf · Submitted to DG SANCO by Dr. Harald Tillmanns PRO ... (e.g. like diamonds,