Were any toxic metals used in the International Space Station?Why are these astronauts green?Why does the ISS not use the most efficient solar panels available?How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here?Do astronauts aboard the International Space Station (ISS) actually use their legs?How much of the International Space Station annual operating costs are due to human crew?What lessons in Space Station design have come out of the ISS?How are EVA's in LEO affected by being at the night side of Earth?Could the space shuttle be permanently left in orbit as a space station?Any “what if” plans for space programs?Do astronauts get Netflix on ISS?Space Station Battle: Could the Almaz gun depressurize the ISS?How is the space station's interior cleaned?Low energy cements for Mars and Callisto. Waterless cement for the Moon. Any good candidates?
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Were any toxic metals used in the International Space Station?
Why are these astronauts green?Why does the ISS not use the most efficient solar panels available?How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here?Do astronauts aboard the International Space Station (ISS) actually use their legs?How much of the International Space Station annual operating costs are due to human crew?What lessons in Space Station design have come out of the ISS?How are EVA's in LEO affected by being at the night side of Earth?Could the space shuttle be permanently left in orbit as a space station?Any “what if” plans for space programs?Do astronauts get Netflix on ISS?Space Station Battle: Could the Almaz gun depressurize the ISS?How is the space station's interior cleaned?Low energy cements for Mars and Callisto. Waterless cement for the Moon. Any good candidates?
$begingroup$
Have any of the following metals been used in the ISS?
Lead: used in some batteries, and in many types of solder.
Mercury: used in some batteries, and in tilt switches (which I would expect have no use on the ISS).
Cadmium: used in some batteries, and in some photoresistors.
Arsenic: used in some LEDs.
If there is a policy prohibiting one or more of them, a citation would be useful.
iss materials
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
$endgroup$
|
show 5 more comments
$begingroup$
Have any of the following metals been used in the ISS?
Lead: used in some batteries, and in many types of solder.
Mercury: used in some batteries, and in tilt switches (which I would expect have no use on the ISS).
Cadmium: used in some batteries, and in some photoresistors.
Arsenic: used in some LEDs.
If there is a policy prohibiting one or more of them, a citation would be useful.
iss materials
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
$endgroup$
3
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
11
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
2
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
1
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
1
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23
|
show 5 more comments
$begingroup$
Have any of the following metals been used in the ISS?
Lead: used in some batteries, and in many types of solder.
Mercury: used in some batteries, and in tilt switches (which I would expect have no use on the ISS).
Cadmium: used in some batteries, and in some photoresistors.
Arsenic: used in some LEDs.
If there is a policy prohibiting one or more of them, a citation would be useful.
iss materials
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
$endgroup$
Have any of the following metals been used in the ISS?
Lead: used in some batteries, and in many types of solder.
Mercury: used in some batteries, and in tilt switches (which I would expect have no use on the ISS).
Cadmium: used in some batteries, and in some photoresistors.
Arsenic: used in some LEDs.
If there is a policy prohibiting one or more of them, a citation would be useful.
iss materials
iss materials
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
asked May 13 at 12:11
Dr SheldonDr Sheldon
6,76722464
6,76722464
3
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
11
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
2
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
1
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
1
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23
|
show 5 more comments
3
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
11
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
2
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
1
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
1
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23
3
3
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
11
11
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
2
2
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
1
1
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
1
1
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23
|
show 5 more comments
4 Answers
4
active
oldest
votes
$begingroup$
The Urine Processor in the Regenerative Environmental Control and Life Support System uses hexavalent chromium as a pretreatment solution for the urine.
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
$endgroup$
2
$begingroup$
+1As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.
$endgroup$
– uhoh
May 13 at 23:46
add a comment |
$begingroup$
note: protests in comments have led me to add the following sentence. Arsenic is a toxic metal and arsenic is used on the ISS, but the arsenic used on the ISS as discussed below is not a toxic metal per se, instead it's a nasty, extremely toxic semiconductor.
GaAs is soluble in HCl which means if you eat it you are eating soluble arsenic. So don't eat it.
Also see this comment.
GaAs and AlGaAs are the standard substrate and heterostructure materials for infrared, red and yellow LEDs and lasers. Indicator lights and optical proximity and interrupt sensors are probably quite numerous and will all have arsenic.
You can see the red LED component in the ISS' new RGB LED lighting in @OrganicMarble's answer to Why are these astronauts green?
UHF and microwave transmitters and receiver front ends for everything from communications and data to radar ranging for spacecraft docking to GPS are likely to have some high-speed GaAs bipolar transistor devices in them.
Arsenic has been a common dopant for a half-century in silicon based electronics and even the substrate wafers themselves can sometimes be moderately doped.
answered May 13 at 13:22
uhohuhoh
43.5k19166544
$endgroup$
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
|
show 8 more comments
$begingroup$
The bearings on the CMG (Control Moment Gyro) rotors use beryllium, which is pretty toxic when you machine it.
answered May 13 at 13:46
TristanTristan
11.5k13858
$endgroup$
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
add a comment |
$begingroup$
The heating system has ammonia in one of its loops, which is very irritating to human eyes, nose, throat, and lungs. On Earth, you can just leave spilled ammonia for a few hours, and it will waft away into the atmosphere until it's at a low enough concentration to be tolerable. In a space habitat, it would be terrible. You might be able to get everyone into space suits, evacuate the atmosphere, and refill the atmosphere. However, the ammonia would seep into fabric and plastic and be difficult to completely exhaust.
Ammonia is a good refrigerant, and it's still usable below the freezing temperature of water, which is why they tolerate it on the ISS. The 2019 news about neopentyl glycol being a viable solid refrigerant is great... if it's usable as a refrigerant at both cold and human-range temperatures, then spacecraft cooling can be made safer and more reliable.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
The Urine Processor in the Regenerative Environmental Control and Life Support System uses hexavalent chromium as a pretreatment solution for the urine.
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
$endgroup$
2
$begingroup$
+1As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.
$endgroup$
– uhoh
May 13 at 23:46
add a comment |
$begingroup$
The Urine Processor in the Regenerative Environmental Control and Life Support System uses hexavalent chromium as a pretreatment solution for the urine.
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
$endgroup$
2
$begingroup$
+1As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.
$endgroup$
– uhoh
May 13 at 23:46
add a comment |
$begingroup$
The Urine Processor in the Regenerative Environmental Control and Life Support System uses hexavalent chromium as a pretreatment solution for the urine.
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
$endgroup$
The Urine Processor in the Regenerative Environmental Control and Life Support System uses hexavalent chromium as a pretreatment solution for the urine.
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
answered May 13 at 12:39
Organic MarbleOrganic Marble
63.8k4173268
63.8k4173268
2
$begingroup$
+1As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.
$endgroup$
– uhoh
May 13 at 23:46
add a comment |
2
$begingroup$
+1As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.
$endgroup$
– uhoh
May 13 at 23:46
2
2
$begingroup$
+1 As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.$endgroup$
– uhoh
May 13 at 23:46
$begingroup$
+1 As your toxin (Cr(VI) (aq)) is a heck of a lot nastier than my toxin (As as GaAs crystal) I think you should get more votes.$endgroup$
– uhoh
May 13 at 23:46
add a comment |
$begingroup$
note: protests in comments have led me to add the following sentence. Arsenic is a toxic metal and arsenic is used on the ISS, but the arsenic used on the ISS as discussed below is not a toxic metal per se, instead it's a nasty, extremely toxic semiconductor.
GaAs is soluble in HCl which means if you eat it you are eating soluble arsenic. So don't eat it.
Also see this comment.
GaAs and AlGaAs are the standard substrate and heterostructure materials for infrared, red and yellow LEDs and lasers. Indicator lights and optical proximity and interrupt sensors are probably quite numerous and will all have arsenic.
You can see the red LED component in the ISS' new RGB LED lighting in @OrganicMarble's answer to Why are these astronauts green?
UHF and microwave transmitters and receiver front ends for everything from communications and data to radar ranging for spacecraft docking to GPS are likely to have some high-speed GaAs bipolar transistor devices in them.
Arsenic has been a common dopant for a half-century in silicon based electronics and even the substrate wafers themselves can sometimes be moderately doped.
answered May 13 at 13:22
uhohuhoh
43.5k19166544
$endgroup$
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
|
show 8 more comments
$begingroup$
note: protests in comments have led me to add the following sentence. Arsenic is a toxic metal and arsenic is used on the ISS, but the arsenic used on the ISS as discussed below is not a toxic metal per se, instead it's a nasty, extremely toxic semiconductor.
GaAs is soluble in HCl which means if you eat it you are eating soluble arsenic. So don't eat it.
Also see this comment.
GaAs and AlGaAs are the standard substrate and heterostructure materials for infrared, red and yellow LEDs and lasers. Indicator lights and optical proximity and interrupt sensors are probably quite numerous and will all have arsenic.
You can see the red LED component in the ISS' new RGB LED lighting in @OrganicMarble's answer to Why are these astronauts green?
UHF and microwave transmitters and receiver front ends for everything from communications and data to radar ranging for spacecraft docking to GPS are likely to have some high-speed GaAs bipolar transistor devices in them.
Arsenic has been a common dopant for a half-century in silicon based electronics and even the substrate wafers themselves can sometimes be moderately doped.
answered May 13 at 13:22
uhohuhoh
43.5k19166544
$endgroup$
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
|
show 8 more comments
$begingroup$
note: protests in comments have led me to add the following sentence. Arsenic is a toxic metal and arsenic is used on the ISS, but the arsenic used on the ISS as discussed below is not a toxic metal per se, instead it's a nasty, extremely toxic semiconductor.
GaAs is soluble in HCl which means if you eat it you are eating soluble arsenic. So don't eat it.
Also see this comment.
GaAs and AlGaAs are the standard substrate and heterostructure materials for infrared, red and yellow LEDs and lasers. Indicator lights and optical proximity and interrupt sensors are probably quite numerous and will all have arsenic.
You can see the red LED component in the ISS' new RGB LED lighting in @OrganicMarble's answer to Why are these astronauts green?
UHF and microwave transmitters and receiver front ends for everything from communications and data to radar ranging for spacecraft docking to GPS are likely to have some high-speed GaAs bipolar transistor devices in them.
Arsenic has been a common dopant for a half-century in silicon based electronics and even the substrate wafers themselves can sometimes be moderately doped.
answered May 13 at 13:22
uhohuhoh
43.5k19166544
$endgroup$
note: protests in comments have led me to add the following sentence. Arsenic is a toxic metal and arsenic is used on the ISS, but the arsenic used on the ISS as discussed below is not a toxic metal per se, instead it's a nasty, extremely toxic semiconductor.
GaAs is soluble in HCl which means if you eat it you are eating soluble arsenic. So don't eat it.
Also see this comment.
GaAs and AlGaAs are the standard substrate and heterostructure materials for infrared, red and yellow LEDs and lasers. Indicator lights and optical proximity and interrupt sensors are probably quite numerous and will all have arsenic.
You can see the red LED component in the ISS' new RGB LED lighting in @OrganicMarble's answer to Why are these astronauts green?
UHF and microwave transmitters and receiver front ends for everything from communications and data to radar ranging for spacecraft docking to GPS are likely to have some high-speed GaAs bipolar transistor devices in them.
Arsenic has been a common dopant for a half-century in silicon based electronics and even the substrate wafers themselves can sometimes be moderately doped.
answered May 13 at 13:22
uhohuhoh
43.5k19166544
edited May 14 at 16:38
answered May 13 at 13:22
uhohuhoh
43.5k19166544
answered May 13 at 13:22
uhohuhoh
43.5k19166544
answered May 13 at 13:22
uhohuhoh
43.5k19166544
43.5k19166544
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
|
show 8 more comments
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
7
7
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
$begingroup$
@Dr Sheldon: Not only is it embedded, the amounts used as dopants are miniscule and the actual LED is on the order of a micrometer thick. Remember that the dose makes the poison: there just isn't enough in the LEDs to be harmful.
$endgroup$
– jamesqf
May 13 at 16:33
5
5
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
$begingroup$
@jamesqf in the case of GaAs (red LEDs, bipolar RF chips) it's the substrate itself that is gallium arsenide, the arsenic is not just a dopant, it's half the wafer! While GaN (blue and white light LEDs) tends to be a thin epitaxial layer on sapphire, the GaAs parts are made from the wafers themselves.
$endgroup$
– uhoh
May 13 at 16:35
1
1
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
$begingroup$
@CBredlow While many satellites use higher efficiency dual and triple junction PV cells that include III-V materials, the ISS' panels are just silicon. See answers to Why does the ISS not use the most efficient solar panels available? as well as How are the silicon PV cells constructed in the ISS's solar panels? Are they as flexible as they appear here? I don't know if there is arsenic doping in them.
$endgroup$
– uhoh
May 13 at 17:50
1
1
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
$begingroup$
The LED wafers used in typical indicator LEDs are pretty small, too -- I don't have an exact size, but it's on the same scale as a grain of salt. Easily under 1% of the volume of the LED.
$endgroup$
– duskwuff
May 14 at 1:07
2
2
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
$begingroup$
@uhoh: Gallium arsenide is not arsenic, any more than carbon dioxide is oxygen. To get into the body, you'd somehow have to decompose it into gallium & arsenic.
$endgroup$
– jamesqf
May 14 at 5:18
|
show 8 more comments
$begingroup$
The bearings on the CMG (Control Moment Gyro) rotors use beryllium, which is pretty toxic when you machine it.
answered May 13 at 13:46
TristanTristan
11.5k13858
$endgroup$
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
add a comment |
$begingroup$
The bearings on the CMG (Control Moment Gyro) rotors use beryllium, which is pretty toxic when you machine it.
answered May 13 at 13:46
TristanTristan
11.5k13858
$endgroup$
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
add a comment |
$begingroup$
The bearings on the CMG (Control Moment Gyro) rotors use beryllium, which is pretty toxic when you machine it.
answered May 13 at 13:46
TristanTristan
11.5k13858
$endgroup$
The bearings on the CMG (Control Moment Gyro) rotors use beryllium, which is pretty toxic when you machine it.
answered May 13 at 13:46
TristanTristan
11.5k13858
answered May 13 at 13:46
TristanTristan
11.5k13858
answered May 13 at 13:46
TristanTristan
11.5k13858
answered May 13 at 13:46
TristanTristan
11.5k13858
11.5k13858
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
add a comment |
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
5
5
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
$begingroup$
Also, heatsinks and ceramic parts in high performance radio and radar gear tend to use beryllium oxide, which is even more toxic if you disintegrate this (brittle!!) material in any way.... Also, bearings are somewhat self machining....
$endgroup$
– rackandboneman
May 13 at 15:24
1
1
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
$begingroup$
@rackandboneman Not even high performance: your microwave oven magnetron has BeO2 ceramic insulators. You recognize it by pink coloring. It's safe unless you're grinding it.
$endgroup$
– user71659
May 13 at 22:10
4
4
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
$begingroup$
A compact 800W transmitter is high performance RF stuff, even if you use it to heat a non-aerospace grade soup.
$endgroup$
– rackandboneman
May 14 at 8:19
add a comment |
$begingroup$
The heating system has ammonia in one of its loops, which is very irritating to human eyes, nose, throat, and lungs. On Earth, you can just leave spilled ammonia for a few hours, and it will waft away into the atmosphere until it's at a low enough concentration to be tolerable. In a space habitat, it would be terrible. You might be able to get everyone into space suits, evacuate the atmosphere, and refill the atmosphere. However, the ammonia would seep into fabric and plastic and be difficult to completely exhaust.
Ammonia is a good refrigerant, and it's still usable below the freezing temperature of water, which is why they tolerate it on the ISS. The 2019 news about neopentyl glycol being a viable solid refrigerant is great... if it's usable as a refrigerant at both cold and human-range temperatures, then spacecraft cooling can be made safer and more reliable.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
add a comment |
$begingroup$
The heating system has ammonia in one of its loops, which is very irritating to human eyes, nose, throat, and lungs. On Earth, you can just leave spilled ammonia for a few hours, and it will waft away into the atmosphere until it's at a low enough concentration to be tolerable. In a space habitat, it would be terrible. You might be able to get everyone into space suits, evacuate the atmosphere, and refill the atmosphere. However, the ammonia would seep into fabric and plastic and be difficult to completely exhaust.
Ammonia is a good refrigerant, and it's still usable below the freezing temperature of water, which is why they tolerate it on the ISS. The 2019 news about neopentyl glycol being a viable solid refrigerant is great... if it's usable as a refrigerant at both cold and human-range temperatures, then spacecraft cooling can be made safer and more reliable.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
add a comment |
$begingroup$
The heating system has ammonia in one of its loops, which is very irritating to human eyes, nose, throat, and lungs. On Earth, you can just leave spilled ammonia for a few hours, and it will waft away into the atmosphere until it's at a low enough concentration to be tolerable. In a space habitat, it would be terrible. You might be able to get everyone into space suits, evacuate the atmosphere, and refill the atmosphere. However, the ammonia would seep into fabric and plastic and be difficult to completely exhaust.
Ammonia is a good refrigerant, and it's still usable below the freezing temperature of water, which is why they tolerate it on the ISS. The 2019 news about neopentyl glycol being a viable solid refrigerant is great... if it's usable as a refrigerant at both cold and human-range temperatures, then spacecraft cooling can be made safer and more reliable.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
The heating system has ammonia in one of its loops, which is very irritating to human eyes, nose, throat, and lungs. On Earth, you can just leave spilled ammonia for a few hours, and it will waft away into the atmosphere until it's at a low enough concentration to be tolerable. In a space habitat, it would be terrible. You might be able to get everyone into space suits, evacuate the atmosphere, and refill the atmosphere. However, the ammonia would seep into fabric and plastic and be difficult to completely exhaust.
Ammonia is a good refrigerant, and it's still usable below the freezing temperature of water, which is why they tolerate it on the ISS. The 2019 news about neopentyl glycol being a viable solid refrigerant is great... if it's usable as a refrigerant at both cold and human-range temperatures, then spacecraft cooling can be made safer and more reliable.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
answered May 13 at 20:42
Christopher HostageChristopher Hostage
1773
1773
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Christopher Hostage is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
add a comment |
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
8
8
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
$begingroup$
Ammonia isn't a metal under normal conditions, but it certainly can be noxious.
$endgroup$
– uhoh
May 13 at 23:48
add a comment |
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3
$begingroup$
Berylium is another toxic metal used in space ships, for instance the Mercury capsule.
$endgroup$
– Uwe
May 13 at 14:01
11
$begingroup$
Lead solder is still considered the best solution, reliability wise, for aerospace grade electronics. Also, in some types of machinery you will need weights, and since you will need the weights to be compact on that kind of vehicle, lead (or even DU!!) would be a likely candidate....
$endgroup$
– rackandboneman
May 13 at 15:28
2
$begingroup$
this and this suggest that Cadmium is unsuitable for vacuum applications due to off-gassing, and Lead is unsuitable for high temperature vacuum applications for the same reason. Tin-Silver solder is suggested to be a better choice for vacuum.
$endgroup$
– SamYonnou
May 13 at 15:34
1
$begingroup$
@GittingGud But tin whiskers might be avoided even more.
$endgroup$
– chrylis
May 13 at 17:00
1
$begingroup$
The title of the question doesn't quite match the body, as it asks about any toxic metals, but the body specifically mentions four. Iron can be toxic, for example.
$endgroup$
– barbecue
May 14 at 16:23