About Tritium
The only radioisotope that we handle is tritium (H³). It can be man-made, but is
also a naturally occurring substance produced by the action of solar and cosmic
radiation on the gases of the upper atmosphere and by the decay of natural
radio-nuclides in rocks and soil. It is a colorless, odorless gas, lighter than air. It
is present in air and water all over the earth and is regularly ingested and
breathed by everyone. All humans contain trace amounts of tritium and other
naturally occurring radioisotopes.
The tritium used to illuminate our signs is man-made and is a by-product of the
CANDU Nuclear Power Plants operated by OPG, Bruce Power, Hydro-Quebec
and New Brunswick Power Nuclear Corporation. We essentially take what is a
waste product from the production of the electricity we use in our homes and
communities and turn it into an important life safety device.
SHIELD SOURCE INCORPORATED
Self-Luminous Safety Signs
Many isotopes are stable and retain their structure indefinitely. However, some
isotopes are not stable and are said to be radioactive. Radioactivity can be
defined as the spontaneous decay of a nucleus to form another nucleus and a
nuclear particle. Tritium is one such radioactive isotope. As the tritium nucleus
decays it emits an electron, causing energy to be released in the form of a beta
particle. It is this electron that energizes the phosphor in our GTLS to create
light. A new nucleus is then formed with two protons and one neutron thereby
becoming a form of non-radioactive helium.
A common way to express the rate of decay of a radioactive element is in terms
of its half-life. Half-life is defined as the time required for the decay of one half
of a sample of a radioactive substance. Tritium has a relatively short half-life of
12.33 years.
Since 1986, we’ve been
identifying the way to safety in
every type of public building
including: offices, apartments,
hotels, schools, hospitals,
stores, museums, restaurants,
and any other facility wherever
exit signs are required.
Tritium’s beta emissions are very weak. No other primary radiation is emitted.
In fact, tritium emits the lowest level of beta radiation energy of all isotopes.
The beta particles are easily stopped by a thin layer of any solid material and
are unable to penetrate our body’s skin. Humans can only be exposed to
radiation from tritium after it has somehow entered the body. It can do this
readily only when the tritium gas is chemically in the oxide form. If inhaled as
gas, tritium is almost immediately expelled from the lungs because the body
cannot absorb it.
If you have questions about the information contained in this brochure, we
invite you to contact us at 705-743-6146 or by email at info@sheildsource.com.
SHIELD SOURCE INCORPORATED
925 Airport Road
RR#5 Municipal Airport
Peterborough, Ontario K9J 6X6
T 705-743-6146 • F 705-743-2942
info@shieldsource.com
www.shieldsource.com
Self-luminous safety signs are
the most energy efficient
safety sign available today.
Self-luminous safety signs require
no batteries or external power
source and are maintenance-free.
About Us
Shield Source Incorporated (SSI) is the world’s leading manufacturer of selfluminous exit and safety signs. We are a privately owned corporation based in
Ontario, Canada and began operation in 1986.
Our signs are used to mark points of egress from all types of public buildings
including hotels, schools, hospitals, office buildings, manufacturing plants, and
other types of facilities where exit signs are required. We also manufacture signs
for use on aircraft.
Our production facility is located at the Peterborough Municipal Airport and we
are licensed by the Canadian Nuclear Safety Commission (CNSC) as a Nuclear
Substance Processing Facility. We are licensed by the CNSC because our signs
are illuminated by radio-luminescent light sources.
About Our Products
Our signs utilize radio-luminescent
light sources. Radio-luminescence is
the creation of light through the use
of ionizing radiation. No external
Day View
Night View (Illuminated)
power source or battery is required ;
instead, our signs are continuously illuminated with Gaseous Tritium Light
Sources (GTLS) that consist of glass tubes, internally coated with phosphor, and
filled with tritium gas. Tritium gas (H³) is an isotope of hydrogen that emits low
energy radiation in the form of beta rays or electrons. These electrons, trapped
within the glass tube, energize the phosphor coating causing the tubes to
continuously emit light. The mechanism is exactly the same as an electrical
fluorescent lamp with the exception that the electrons are supplied by the
tritium instead of by an electrically ionized gas.
Our self-luminous signs are subjected to rigorous safety testing to ensure their
safe use in the public domain. They are approved for use by the CNSC, the US
Nuclear Regulatory Commission, and the National Fire Protection Association.
They are Listed in Canada and the United States by Underwriters Laboratories
to the UL924 Code for Emergency Lighting Products, and meet the
requirements of the National and Provincial Building Codes.
Self-luminous safety signs are the most energy efficient safety sign available
today. They require no batteries or external power source, are maintenancefree, and meet all applicable fire and building codes for up to twenty years.
About Our Manufacturing Facility
Our manufacturing facility is located at the Peterborough
Municipal Airport in a 300m² portion of Building #16
located just east of the new Airport Terminal. Here we
produce the GTLS and assemble them into our exit and
safety signs for distribution to customers around the world.
All manufacturing processes have been designed to
ensure the protection of our workers, the public, and the
environment. Our workers are required to participate in our
weekly Dosimetry program which tests them for Tritium
levels. While the federally allowable effective dose for a
nuclear energy worker is 50 mSv for one year and up to a
maximum of 100 mSvr over five years, the maximum dose
received by any of our workers in 2010 was 1.99 mSv and
the maximum five-year dose to any of our workers over the
past five years was 7.3 mSv.
All air emissions, water discharges, and waste disposal from
our plant are monitored and controlled with oversight
provided by the CNSC. Additionally, we perform
environmental sampling of air, surface water, well water,
and vegetation within a 17-kilometer radius of our facility.
The results of our monitoring and sampling activities are
published annually in our Annual Environmental
Compliance Report which is made available on our website
after review and approval by the CNSC.
This information is used to calculate the potential dose to
the critical receptor group, consisting of a hypothetical
infant, child, and adult. This group hypothetically lives
within 0.2 kilometers of our plant and consume their
drinking water, milk, produce and meat from local wells,
livestock and vegetation raised and grown within this same
0.2 kilometer radius of our facility. This is an extremely
conservative calculation because the conditions to fulfill
these criteria do not exist. Yet, even with these impossible
assumptions, the potential dose is calculated to be less
than 5% of the federally allowable limit to the public of
1 mSv/year above background radiation.
Self-luminous safety signs meet all
applicable fire and building codes
for up to twenty years.
Self-luminous safety signs require
no batteries or external power
source and are maintenance-free.
About Us
Shield Source Incorporated (SSI) is the world’s leading manufacturer of selfluminous exit and safety signs. We are a privately owned corporation based in
Ontario, Canada and began operation in 1986.
Our signs are used to mark points of egress from all types of public buildings
including hotels, schools, hospitals, office buildings, manufacturing plants, and
other types of facilities where exit signs are required. We also manufacture signs
for use on aircraft.
Our production facility is located at the Peterborough Municipal Airport and we
are licensed by the Canadian Nuclear Safety Commission (CNSC) as a Nuclear
Substance Processing Facility. We are licensed by the CNSC because our signs
are illuminated by radio-luminescent light sources.
About Our Products
Our signs utilize radio-luminescent
light sources. Radio-luminescence is
the creation of light through the use
of ionizing radiation. No external
Day View
Night View (Illuminated)
power source or battery is required ;
instead, our signs are continuously illuminated with Gaseous Tritium Light
Sources (GTLS) that consist of glass tubes, internally coated with phosphor, and
filled with tritium gas. Tritium gas (H³) is an isotope of hydrogen that emits low
energy radiation in the form of beta rays or electrons. These electrons, trapped
within the glass tube, energize the phosphor coating causing the tubes to
continuously emit light. The mechanism is exactly the same as an electrical
fluorescent lamp with the exception that the electrons are supplied by the
tritium instead of by an electrically ionized gas.
Our self-luminous signs are subjected to rigorous safety testing to ensure their
safe use in the public domain. They are approved for use by the CNSC, the US
Nuclear Regulatory Commission, and the National Fire Protection Association.
They are Listed in Canada and the United States by Underwriters Laboratories
to the UL924 Code for Emergency Lighting Products, and meet the
requirements of the National and Provincial Building Codes.
Self-luminous safety signs are the most energy efficient safety sign available
today. They require no batteries or external power source, are maintenancefree, and meet all applicable fire and building codes for up to twenty years.
About Our Manufacturing Facility
Our manufacturing facility is located at the Peterborough
Municipal Airport in a 300m² portion of Building #16
located just east of the new Airport Terminal. Here we
produce the GTLS and assemble them into our exit and
safety signs for distribution to customers around the world.
All manufacturing processes have been designed to
ensure the protection of our workers, the public, and the
environment. Our workers are required to participate in our
weekly Dosimetry program which tests them for Tritium
levels. While the federally allowable effective dose for a
nuclear energy worker is 50 mSv for one year and up to a
maximum of 100 mSvr over five years, the maximum dose
received by any of our workers in 2010 was 1.99 mSv and
the maximum five-year dose to any of our workers over the
past five years was 7.3 mSv.
All air emissions, water discharges, and waste disposal from
our plant are monitored and controlled with oversight
provided by the CNSC. Additionally, we perform
environmental sampling of air, surface water, well water,
and vegetation within a 17-kilometer radius of our facility.
The results of our monitoring and sampling activities are
published annually in our Annual Environmental
Compliance Report which is made available on our website
after review and approval by the CNSC.
This information is used to calculate the potential dose to
the critical receptor group, consisting of a hypothetical
infant, child, and adult. This group hypothetically lives
within 0.2 kilometers of our plant and consume their
drinking water, milk, produce and meat from local wells,
livestock and vegetation raised and grown within this same
0.2 kilometer radius of our facility. This is an extremely
conservative calculation because the conditions to fulfill
these criteria do not exist. Yet, even with these impossible
assumptions, the potential dose is calculated to be less
than 5% of the federally allowable limit to the public of
1 mSv/year above background radiation.
Self-luminous safety signs meet all
applicable fire and building codes
for up to twenty years.
About Tritium
The only radioisotope that we handle is tritium (H³). It can be man-made, but is
also a naturally occurring substance produced by the action of solar and cosmic
radiation on the gases of the upper atmosphere and by the decay of natural
radio-nuclides in rocks and soil. It is a colorless, odorless gas, lighter than air. It
is present in air and water all over the earth and is regularly ingested and
breathed by everyone. All humans contain trace amounts of tritium and other
naturally occurring radioisotopes.
The tritium used to illuminate our signs is man-made and is a by-product of the
CANDU Nuclear Power Plants operated by OPG, Bruce Power, Hydro-Quebec
and New Brunswick Power Nuclear Corporation. We essentially take what is a
waste product from the production of the electricity we use in our homes and
communities and turn it into an important life safety device.
SHIELD SOURCE INCORPORATED
Self-Luminous Safety Signs
Many isotopes are stable and retain their structure indefinitely. However, some
isotopes are not stable and are said to be radioactive. Radioactivity can be
defined as the spontaneous decay of a nucleus to form another nucleus and a
nuclear particle. Tritium is one such radioactive isotope. As the tritium nucleus
decays it emits an electron, causing energy to be released in the form of a beta
particle. It is this electron that energizes the phosphor in our GTLS to create
light. A new nucleus is then formed with two protons and one neutron thereby
becoming a form of non-radioactive helium.
A common way to express the rate of decay of a radioactive element is in terms
of its half-life. Half-life is defined as the time required for the decay of one half
of a sample of a radioactive substance. Tritium has a relatively short half-life of
12.33 years.
Since 1986, we’ve been
identifying the way to safety in
every type of public building
including: offices, apartments,
hotels, schools, hospitals,
stores, museums, restaurants,
and any other facility wherever
exit signs are required.
Tritium’s beta emissions are very weak. No other primary radiation is emitted.
In fact, tritium emits the lowest level of beta radiation energy of all isotopes.
The beta particles are easily stopped by a thin layer of any solid material and
are unable to penetrate our body’s skin. Humans can only be exposed to
radiation from tritium after it has somehow entered the body. It can do this
readily only when the tritium gas is chemically in the oxide form. If inhaled as
gas, tritium is almost immediately expelled from the lungs because the body
cannot absorb it.
If you have questions about the information contained in this brochure, we
invite you to contact us at 705-743-6146 or by email at info@sheildsource.com.
SHIELD SOURCE INCORPORATED
925 Airport Road
RR#5 Municipal Airport
Peterborough, Ontario K9J 6X6
T 705-743-6146 • F 705-743-2942
info@shieldsource.com
www.shieldsource.com
Self-luminous safety signs are
the most energy efficient
safety sign available today.