Transcript Blake International Limited

Blake International
Limited
Conventional Ammunition,
Alternative Materials
& Risk
Lead Ammunition
Lead’s density, malleability
and casting characteristics
make it an ideal material for
use in the mass manufacture of
projectiles and it has been used
for this application since at
least the time of the ancient
Greeks.
Today, lead still remains the
primary material of choice for
bullet and shot manufacture.
Projectile Materials
The Alternatives to Lead-Antimony Alloys
COST vs PERFORMANCE
25
W-Poly
Relative Cost
20
W
Cu -Poly
15
W-Sn
W-Steel (TNI)
W-Bronze
10
Cu
Sn Bi
Cu-Sn
Zn
Pb-Zn
Pb
Steel
Pb-Sb
5
0
0
5
10
Density
15
20
Lead is Durable
Ely Cathedral:
The central tower collapsed in
the reign of Henry IV. It was
replaced by a hexagonal lantern
tower, constructed of oak clad
with lead 1322 ~1342.
Lead is Durable
Roman Baths at Bath,
Somerset.:
Built on a pre-roman
pagan site, the Roman
baths were constructed
100-300AD.
The lead plumbing is
still in place and in
working condition after
over 1,700 years!
Original
plumbing
Development of Lead-Antimony Alloys
►
►
►
►
Corrosion; electrolytic processes /
redox effects.
Batteries are controlled redox
corrosion systems.
Faure invention 1881  improved
reliability of the redox corrosion
process through; ‘initiation’ (Pb0 /
PbO2 / PbSO4) and improved
‘electron yield’ of the plate (Pb-Sb
alloy)  Automotive Battery
Downside  increased corrosion on
+ve Plate. (ANODIC CORROSION)
© Copyright 2004 Cylenchar Limited
Construction of Lead-Acid Batteries
► Connecting
stems and posts - 4% Sb.
► Negative Plates - 2% Sb Lead alloy.
► Positive Plates have 0% Sb or low Sb + other
metals; Ca, Se, As, Ag, Al, Sn, etc.
► Recycled Battery Lead contains ~2% Sb. For
positive plate production of limited use as it’s
too corrosive 
► ~1.4 M tonne p.a. surplus Pb-Sb alloy 
► World wide ~300,000 tonnes p.a. Pb-Sb alloy
used in projectile manufacture.
Comparative Corrosion of 2mm Pure Lead Shot
vs US No.8 Lead- (1.25%w/w)Antimony Shot
No.8 Lead-Antimony Shot and Pure Lead shot (2mm),
Corrosion in Acid Rain vs Time
20
Pb mg/L
15
10
5
0
-5
0
20
40
60
80
100
-10
Days Leaching
Pb-1.25%Sb Alloy
y=0.228x-5.29
Pb 99.999%w/w
y=0.0129x+0.382
© Copyright 2004 Cylenchar Limited
Roman Lead Sling Shot
Excavated from Roman sites on the
Danube. May date from ~100BC, and
are no older than Trajan’s Dacian
campaign ~100AD. Slow corroding
Pb-4%As alloy.
UK-No7.5 Shot; 4% Sb, >1%O
Polished un-etched cross-sections
© Copyright 2004 Cylenchar Limited
© Copyright 2004 Cylenchar Limited
US-#8 Shot ~1.25% Sb, 2.2%O
Polished un-etched crosssections
The Contents and Structure of
‘Commercial’ Lead Shot
►
►
►
►
►
Lead-antimony alloy shot isn’t homogeneous, it’s a
heterogeneous material, made up of:Lead-antimony poor alloy granules separated by leadantimony rich (>10%Sb) brittle, ‘porous’ dendritic
eutectic alloy. (Pb-As / Pb-Sn alloys have lower redox
potential, with coarser and tighter crystal structure)
High levels of antimony at the surface.
Other metals, (As, Ag, Al, Cu, Sn, Zn) in dendritic
zone.
Contains ~6-12%w/w lead oxide and sulphate, from
secondary lead (result of crudely melted old batteries!)
Summary of Corrosion Rates for Shot
Sample
Linear
Slope
mg/Litre/day
Approx.
Corrosion
Rate
mg/m2/day
Relative
Corrosion
Rate
Pure Lead
(~2mm dia)
0.0129
0.486
0.045 / 1.00
No8 LeadAntimony Shot
0.228
10.868
1.00 / 22.4
No 6 Steel Shot
5.52
224.4
20.6 / 462.5
No8 LeadAntimony Shot +
Steel Shot
1.430
68.163
6.27 / 140.3
No8 LeadAntimony Shot +
1% IFS
0.00018
0.0086
0.0008 / 0.018
Heavy Metals Released on Dilution of
Steel Shot Corrosion Product
No.8 Lead-Antimony Shot and No.6 Steel Shot
Soluble Metals in Diluted Corrosion Product
Dissolved mg/L
0.2
0.15
0.1
0.05
0
0
10
20
x Dilution
Pb Sb
© Copyright 2004 Cylenchar Limited
Electrochemical Series of Selected Ammunition Metals and
their Contaminants - Thermodynamic issues
Eq.No
Redox Reaction
Redox Potential
Eo (volts)
1
Ag+(aq) + e- 
Ag(s)
+0.7996
2
Bi3+(aq) + 3e- 
Bi(s)
+ 0.381
3
Cu2+(aq) + 2e- 
Cu(s)
+0.3419
4
Sb3+(aq) + 3e- 
Sb(s)
+0.11
5
W3+(aq) + 3e- 
W(s)
+0.1
6
Pb2+(aq) + 2e- 
Pb(s)
-0.1262
7
Sn2+(aq) + 2e- 
Sn(s)
-0.1375
8
As3+(aq) + 3e- 
As(s)
-0.32
9
Fe2+(aq) + 2e- 
Fe(s)
-0.44
10
Ni2+(aq) + 2e- 
Ni(s)
-0.4257
11
Zn2+(aq) + 2e-  Zn(s)
-0.7618
12
Mn2+(aq) + 2e- 
Mn(s)
-1.185
Redox Corrosion Mechanism
of Lead-Antimony Alloy – Kinetic Issues
METAL-WATER INTERFACE
Anodic Region:
Pb2+ Pb(OH)2 / PbOHCO3  PbO / PbO2
Sb3+ (aq)  Sb(OH)3 mildly acidic +
High Redox potential ~2.0eV
2+ + 2e- fast
CORROSION
Fe  FeACCERATED
BY
> ACIDITY,
Fe2+ + O2>
SURFACE
Fe3+ fast, AREA
Acidic&
Aq ion + <
high redox
PASSIVATION
potential ~2.5eV
Cathodic Region:
O2 (g) + 2H2O +
4e-

4OH- (aq)
H2CO2(aq) + 2OH-(aq)  CO3-(aq) + H2O
METAL
ANODIC REGION
Pb(s)  Pb2+ (aq) + 2e-
Surface Area Increases due
to porosity / frangibility
Sb(s)  Sb3+(aq) + 3eIRON >> CORROSION
e- generated at anodic
region released at the
cathodic region
PbO2 + H2O+ 2e-  PbO +2OH-
+ 3e- SLOWED
 Sb(s) BY
INITIALSb3+(aq)
CORROSION
2+ + 2e-  Fe
FePASSIVATION
PbO
Fe3+(aq) + e-  Fe2+(aq)
METAL
CATHODIC REGION
UK-5.56 Core; nominally 10% Sb, 3.8%O
Polished un-etched cross-section
© Copyright 2004 Cylenchar Limited
US-5.56 Core; <1% Sb, >7-18%O
Polished un-etched cross-section
© Copyright 2004 Cylenchar Limited
Lead/Steel - Environmental Risk Factors
► Lead
shot and bullets from ‘secondary lead’
contain ‘Toxic’ lead oxide / sulphate.
► Antimony and other impurities increase
corrosion rates.
► Steel shot fired onto legacy lead  High Redox
material + lower pH  increases Pb and Sb
corrosion + Fe contaminants; e.g. Ni, Mn.
► Steel shot fast corroding  Fe and Mn oxides
 ‘transport metal’ for heavy metals; e.g. Pb,
Sb, As, etc.
What should be the Risk status of
Lead Projectiles,
harmful irritant metal ?
or Toxic oxide?
Does Steel solve or compound
the problem?
The Properties of Tungsten
►High
density metal 19g/cc
►m.pt >3,400oC  W-Powder Technology
►Inert, Insoluble and Non-toxic ???
►Noble metal  High redox potential.
►W readily oxidized in air at RT, rapid
oxidation above 200oC#
►W powder is PYROPHORIC!
#"Tungsten, Properties, Chemistry, Technology of the element, Alloys, and Chemical Compounds" by
Erik Lassner and Wolf-Dieter Schubert, Kluwer Academic/Plenum Publishers 1999
ISBN 0306-45053-4
The Properties of Tungsten#
– Low solubility in acids, soluble to alkali,
and aqueous oxygenating environments:
Anodic Oxidation; (i) W + 8OH-  WO42- + 6e- + 4H2O
Cathodic reduction; (ii) O2 + 2H2O + 4e-  4OH► Dissolution rate slow (30µm) pure W powder at 10%w/v
in pure water  ~10mgW/litre/day.
► Aqueous solubility of W metal  75mg/Litre at 38oC
equilibrium, i.e. pH 3.2. Passivates only below pH 4.
► H2WO4.H2O - pKa 3.6 and very soluble and colloidal.
► Soil based electrolytes, Fe and Pb  increase solubility
and dissolution significantly! E.g. FeOH.WO4(5H20)
and PbWO4 (Stolzite) sink effects.
► Insoluble!
#"Tungsten, Properties, Chemistry, Technology of the element, Alloys, and Chemical Compounds" by
Erik Lassner and Wolf-Dieter Schubert, Kluwer Academic/Plenum Publishers 1999
ISBN 0306-45053-4
The Properties of Tungsten
Corrosion of
machinable
tungsten steel
by oxygenated
water
SR Instrumentation Engineering Group Report, "Erosion/Corrosion of Machinable Tungsten in Water“,
Jeff T. Collins, Advanced Photon Source Experimental Facilities Division, SR Instrumentation Engineering
Group, November 30, 2000
Redox Corrosion of Tungsten Powder in Alloy
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Redox Corrosion of Tungsten Powder in Alloy
M+
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
M+
M+
M+
W
W
M+
M+
W
W
W
W
W
W
W
W
W
W
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
M+
W
W
W
W
W
W
W
M+
W03
W
M+
M+
M+
W
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W03
M+
W
M+
W
W
M+
M+
W
W
W
W
W
W
W
W
M+
W
W
W
M+
W
W
W
M+
W
W
W
W
M+
M+
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
W
W
W
W
W
W
W
W
W
W
M+
W
W
W
W
W03
W
W
W
M+
M+
W
M+
W
W
M+
M+
W
W
W
M+
W
W
W
M+
W
W
W
M+
W
W
W
W
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
M+
W
W
W
W
W
W
W
W
W
M+
W
W
M+
M+
W
W
M+
W
W
W
W
M+
M+
W
W
M+
W
W
W
M+
M+
W
W
W
W
W
W
W
W
M+
M+
W
M+
M+
W
M+
M+
W
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
M+
W
W
W
W
W
W
W
W
W
W
W
W
W
M+
W
M+
W
M+
W
W
W
M+
W
M+
M+
W
W
M+
W
W
W
M+
M+
W
W
M+
M+
M+
W
W
M+
WO3
M+
M+
W
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
W
W
M+
W
W
W
W
W
W
W
W
W
W
M+
W
M+
M+
M+
M+
M+
W
W
M+
W
W
W
M+
M+
W
W
M+
W
W
W
M+
W
W
W
M+
WO3
W
W
M+
M+
W
M+
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
M+
M+
W
W
M+
W
W
W
M+
WO3
W
W
M+
W
M+
M+
W
W
W
W
W03
W
W
W
W
M+
M+
W
W
M+
W
M+
WO3
W
W
W
W
W03
M+
M+
M+
M+
M+
M+
W
M+
M+
M+
M+
Redox Corrosion of Tungsten Powder in Alloy
W
W
W
W
W
W
WO3
W
W
W
W
W
W
W
W
W03
W
W
W
W
W
WO3
W
Colloidal tungsten
exposed and rendered
soluble via oxidation.
WO42- salts formed with
matrix corrosion products
and soil contaminants.
W
W
W
W
Base metal matrix
dissolves via redox
induced corrosion.
pH falls giving deposition of nonprotective WO3 and soluble
isotungstates. If pH remains neutral
or alkali, corrosion continues apace
releasing tungstates.
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
WO3
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Dissolution & Decay of Tungsten Polymer composite
W
W
WO3
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Oxidation and
dissolution of
tungsten
Coincidental with,
or preceded by
decay of the
polymer matrix.
Assisted by
physical rupture
of matrix by
reactive W oxides
Dissolution & Decay of Tungsten Polymer composite
Acid Hydrolysis
W
W
WO3
W
W
W
W
R1-CH2-CO2H + H2N-CH2-R2
R1-CH2-CO-NH-CH2-R2 + H3O+
W
W
W
W
W
W
R1-CH2-CO-NH-CH2-R2
W
W
W
W
W
R1-CH2-CO-NH-*CH-R2 + O2
W
W
W
R1-CH2-CO-NH-CO-R2 + H2O
W / Cu free-radical induced oxidation
(Plastics Cancer)
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Chang et al (1998)
► “When
W was coupled to Fe#, CDA (Cu-Ni Bronze) and
Invar (Ni-iron), significantly large current densities
were measured. This suggest that corrosion protection
schemes will need to be developed for W-alloys using
these materials in the matrix.”
► Similar
materials have been approved for sale in the US
as ‘NON-TOXIC” under US Fish & Wildlife
Department regulations. (Submissions cite limited
duration in-vivo studies on waterfowl.)
Ref: Galvanic Corrosion of Tungsten Coupled With Several Metals/Alloys;
Chang F.C., Beatty J.H., Kane M.J., Beck J;
Army Research Lab, Aberdeen Proving Ground, MD
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Meijer et al (1998)
►
W-Ni alloys with Fe, Cu, Co, Mn and Ta studied in relation to
use at Elgin AFB. 10 year projection/assumption: Average
0.55% w/w W and 0.036% w/w Ni over surface area to a depth
of 1cm, with average particle size 0.5cm.
►
Bare alloy (Stock Rod, not heat treated) discs, (26-33 mm dia) in
rainfall event model ‘drip tests’ over a ~6 hour period, yielded:
W at 8.9 - 98.1 mg/L (no soil)
Ni at 5.4 - 33.7 mg/L (no soil)
Ni at 4.5 - 247 mg/L (in soil)
►
Likely corrosion products include Cu-Ni and Ni Tungstates.
Ref: Environmental Effects of Tungsten & Tantalum Alloys;
Mejier A, Wroblicky G, Thrung S & Marcell MW; GCX Albuquerque NM; 1998
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Meijer et al (1998)
W in Bonze alloy subject
to ground water. Tungsten
particles preferentially
W Grains
dissolve and give
increased acidity.
W in Bonze alloy subject
to sea water. Bronze
matrix preferentially
dissolves.
WO3
Ref: Environmental Effects of Tungsten & Tantalum Alloys;
Mejier A, Wroblicky G, Thrung S & Marcell MW; GCX Albuquerque NM; 1998
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Meijer et al (1998)
W in Bonze alloy subject to
ground water. Tungsten
particles preferentially
dissolve.
WO3?
Ref: Environmental Effects of Tungsten & Tantalum Alloys;
Mejier A, Wroblicky G, Thrung S & Marcell MW; GCX Albuquerque NM; 1998
With increasing acidity get
formation of a Yellow scale
NB: H2WO4.H2O (Yellow),
W03.2H20 (white)
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Meijer et al (1998)
“Tantalum and tungsten are strongly bound on mineral grains in
the soil zone and will remain in this zone indefinitely”
► Unlikely to remain immobile, in our experience. Possibility of
‘soil saturation’ and/or ‘facilitated transport’ not considered.
Dissolution tests done in absence of iron. Leach model sample
seriously flawed!
► “Tungsten and tantalum appear to have minimal human and
ecological impact based on the current available data”
► Scant evaluation of available tox. data!
► “Analysis of potential ecological risks indicates no unacceptable
risks will result from use of tantalum and / or tungsten alloys in
the testing of penetrator munitions”
► Independent comment: “largely inconclusive with regards to the
geochemical behaviour of tungsten and tungsten alloys”
►
Ref: Environmental Effects of Tungsten & Tantalum Alloys;
Mejier A, Wroblicky G, Thrung S & Marcell MW; GCX Albuquerque NM; 1998
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Middleton (1998)
►
►
►
►
►
►
Rapid dissolution of W from both W-Nylon an W-Tin bullet
residues in sand column leaching studies:
deionised water,
to 15.6 mg/L W.
simulated sea water,
to 66 mg/L W.
simulated rain water,
to 105 mg/L W.
On aging 130oC, 48 days leach rates
to 9,510 mg/L W.
W-Nylon residues with iron piercing tips faired least well.
Mixed W and WO3 in rainwater,
to 462 mg/L W.
Mixed W, WO3 and H2WO4 in rainwater, to 2,660mg/L W.
“It appeared that the tungsten powder oxidizes to form tungsten
oxide, which is insoluble in water and thus relatively stable in the
environment.”
Ref: Elimination of Toxic Heavy Metals from Small Caliber Ammunition.
Middleton J., SERDIP Report, ARDEC Picatinny 1998
Inherent Redox Instability of Tungsten Powder
Technology – e.g. Middleton (1998)
► W uptake
by Beans and Rye Grass, Growth stunted.
Possibilities for phyto-remediation?
► Earthworm toxicity study shows weight loss. W-Tin
fared better than Pb - Worms on walls of the W test bin!
“Earthworms were not adversely affected”
Worm
aversion test FAIL!
► W-Nylon effect on earthworms not studied. Too acidic?
► Earthworms in long term study contained 213ppm W:Risk to food chain?
► W binds strongly to soils/biomass. ‘Twin edged sword.’
Other metals may bind strongly to colloidal W!
Ref: Elimination of Toxic Heavy Metals from Small Caliber Ammunition.
Middleton J., SERDIP Report, ARDEC Picatinny 1998
Inherent Redox Instability of Tungsten Powder
Technology
Corroding W-Nylon
round in situ.
Massachusetts
Military
Reservation.
Picture courtesy of Mark Begley
Commonwealth of Massachusetts
Environmental Management
Commission
ECOMASS 10002D95, Tungsten
in polyamide copolymer, 11g/cc
Fresh Surface, injection moulded
tile. Mole Ratio W:O 1:3.5
© Copyright 2004 Cylenchar Limited
ECOMASS 10002D95 Aged Surface,
Water 98oC 3 hr. Mole Ratio W:O 1:4.
Erosion & Oxidation. Carbon Matrix
disappears. Ca detected
© Copyright 2004 Cylenchar Limited
Tungsten – Toxicity
► Oral
►
Toxicity:
W – Irritant, LD50 Rat 2-5g/Kg, WO3 LD50 Rat 840-1,050mg/Kg.
- Mildly Toxic
Soluble W compounds are Toxic. Sub-acute effects include;
weight loss, breathing problems, blood changes, decreased sperm
motility with genetic changes, non-specific neurological
disorders including tremors, adverse effects on the liver, spleen
and kidneys, molybdenum deficiency, non-specific metabolic
changes. (Lit. Rev. Haneke 2003)
► Cancer: - Mildly Carcinogenic – Females at Greater Risk.
5ppm W in drinking water over lifetime produced tumours in
65% of female rats and 15% male rats. (Schroder & Mitchener 1975)
Lung cancer mortality in tungsten miners has been attributed to
silicosis. Recent studies indicate no link between the silicosis
and lung cancer. (Chen et al 1994)
Tungsten – Toxicity
►Cancer
promoter:
Mammary cancer promoting effect of tungsten, an antagonist of
molybdenum, noted in mice (Wei et al 1987). Mixed metal Tungsten
ore increases the growth rate of leukemia cells (Witten et al 2005)
►Synergistic
effects:
The toxicity of Co is increased by the presence of WC. (Roesems et al
1997) WC-Co is more genotoxic than Co and WC alone. (De Boeck et
al 2003)
►DNA Affecter:
►
Tungsten particle bombardment used to cleave DNA in creation
of GM organisms.
Tungsten metal particles in suspension promote breakage of
Cellular DNA, The rate of DNA self repair, not high enough to
restore all genome functions.  potential for adverse effects
(Krysiak et al 1999).
Tungsten – Toxicity Data
► Reproductive Affecter
/ Teratogen:
Oral Rat, 1.2 mg/kg (30- 35 week prior to copulation
and 1-2 weeks pregnant), Musculoskeletal defects and
embryonic lethality. (Mezhdunarodnaya Kniga, 1936 and 1939 respectively)
/ Dangerous Properties of Industrial Materials, 7th Ed., by N. Irving Sax and Richard J.
Lewis.
► “There
is anecdotal evidence of tungsten being a
teratogen or a substance which causes deformities in
developing fetus. However, other dietary and cultural
factors could not be ignored in these studies. Thus
tungsten is considered to be an experimental teratogen
that has experimental reproductive effects”
Toxicity of tungsten, molybdenum and tantalum and the environmental and
occupational laws associated with their manufacture, use and disposal. Kerwien S.C.,
ARDEC Picatinny Arsenal NJ, Management Engineering 1996
Tungsten Powder Technology Projectile Toxicity
Miller et al (2005)
►
Rats implanted with, high and low
dose W-Ni alloy and Ni alloy.
► Noticeable changes in the animals
blood and liver function after 1
month.
► Aggressive tumours around the
implant within 5 months.
► 100% of test subjects developed
tumours.
► Cancers metastasised to the lungs.
► High dose W alloy implants
developed tumours faster than low
Kalinic FJ, Emond CA, Calton TK, Mog SR, Colemen GD, Kordell
dose, and faster than nickel, a
JE, Miller AC, McClain DE, Embedded Weapons-Grade Tungsten
known carcinogen.
Alloy Shrapnel Rapidly Induces Metastatic High Grade
Rhabdomyosarcomas in F344 Rats (2005)
Tungsten – Ecotoxicity
► Soluble W toxic
to red worms , plants, microbes.
0.01μg/L in soil microbial yield reduce 8%.
‘Volume of Toxic Influence’. Tungsten particles had ability
to affect microbial communities at >10 times the radius of
the particle. (Strigul et al, 2003)
► 3% (NH4)2WO4/WO3 incubated in soil for 3 months, 95%
death of soil microbe population. (Dermatas et al, 2004)
► 1% W incubated in soil for 1 year significant death of soil
microbe population 68%. Toxic to nematodes, mites and
ticks. (Braida et al, 2004)
► NB:Tungstates - KNOWN PESTICIDES & BIOCIDES.
W - Environmental Risk Factors
► W-Powder
technology potentially unstable.
► ‘INSOLUBLE’, irritant W powder readily oxidises
to harmful and toxic ‘SOLUBLE’ W oxides.
► Current W-materials contaminated?
► Frangible rounds  maximise risk.
► Redox effect  corrosion of legacy metals.
► Lower pH  faster corrosion and leaching.
► Colloidal W, a potential ‘transport metal’.
W - Environmental Risk Factors
► W not
fully toxicologically evaluated. However,
significant data implicating W as a reproductive
affecter and cancer promoter.
► Toxic to flora and fauna.
► Uptake by plants and invertebrates  Food Chain.
► Prior risk appraisals flawed and inconclusive.
Probability and severity of risk understated 
► Promotion of W as insoluble, inert and non-toxic
has lead to inappropriate and widespread use.
Tungsten,
inert, insoluble and non-toxic ?
or the New Asbestos?
For further information contact:
Dr Peter J. Hurley
Blake International Limited
Tel: +44-(0)1484-517417
Fax: +44-(0)1484-516098
e-mail: [email protected]