10 Aug Ionizing Radiation – Radiation in the Workplace

Ionizing Radiation – Radiation in the Workplace

Ionizing radiation is used in many workplaces for activities such as industrial radiography, medical imaging, measurement and testing, research, and specialized construction applications. Although radiation provides important benefits, exposure must be carefully controlled because excessive exposure can damage living tissue and increase health risks.

What Is Ionizing Radiation?

Radiation is energy that travels through space or matter. Some forms of radiation have enough energy to remove electrons from atoms and are classified as ionizing radiation.

Common types include:

• X-rays.
• Gamma rays.
• Alpha particles.
• Beta particles.
• Neutrons.

Ionizing radiation cannot normally be seen, smelled, tasted, or felt. Specialized instruments are required to detect and measure it.

How Exposure Occurs

Radiation exposure can occur in two primary ways:

External Exposure

External exposure occurs when a radiation source outside the body exposes a worker to ionizing radiation. Examples include X-ray equipment and radioactive sources used for industrial radiography.

External exposure generally ends when the source is removed, shielded, or sufficiently separated from the worker.

Internal Exposure

Internal exposure occurs when radioactive material enters the body through:

• Inhalation.
• Ingestion.
• Absorption through wounds or other pathways.

Once radioactive material enters the body, it may continue exposing internal tissues until it is eliminated naturally or the radioactive material decays.

Health Effects

The health effects of ionizing radiation depend on factors such as the amount of radiation received, dose rate, type of radiation, duration of exposure, and the tissues or organs exposed.

High radiation doses can cause serious tissue and organ damage. Depending on the circumstances, radiation exposure can also increase the long-term risk of cancer.

Because health effects may not be immediately apparent, workers must never rely on their senses to determine whether an area or source is safe.

Time, Distance and Shielding

Three fundamental methods are used to minimize occupational radiation exposure:

Time

Minimize the amount of time spent near a radiation source. The less time you are exposed, the lower your radiation dose.

Distance

Maximize your distance from the radiation source. Increasing the distance between yourself and the source can significantly reduce exposure.

Shielding

Use appropriate shielding between yourself and the radiation source. The required shielding depends on the type and energy of the radiation.

Remember: Minimize time, maximize distance, and use appropriate shielding.

Industrial Radiography

Industrial radiography uses ionizing radiation to inspect welds, piping, structures, and other materials for defects that may not be visible from the surface.

Because radiography sources can produce high radiation levels, only properly trained and authorized employees may perform this work.

Employees involved in radiography must:

• Follow established radiation-safety procedures.
• Maintain required restricted or controlled areas.
• Observe warning signs, barricades, and radiation-area postings.
• Use required radiation-monitoring equipment.
• Never assume that a radioactive source has returned to its shielded position.
• Verify source conditions with an appropriate radiation survey instrument as required.
• Keep unauthorized employees away from radiography operations.

Never cross a radiography barricade or enter a posted radiation area unless you are specifically authorized to do so.

Radiation Monitoring

Employees who work with or around ionizing radiation may be required to use monitoring devices such as:

• Personal dosimeters.
• Electronic dosimeters.
• Direct-reading instruments.
• Alarming radiation-rate meters.
• Radiation survey meters.

Monitoring equipment must be used according to applicable procedures and regulatory requirements.

Never tamper with, exchange, deliberately expose, or misuse a personal radiation-monitoring device.

Prevent Radioactive Contamination

Radioactive contamination occurs when radioactive material is deposited on a person, surface, equipment, or within an area.

Where radioactive materials are handled:

• Follow established contamination-control procedures.
• Do not eat, drink, smoke, chew gum, or apply cosmetics in prohibited areas.
• Wear required gloves, protective clothing, respiratory protection, or other PPE.
• Survey work areas and equipment as required.
• Do not remove potentially contaminated materials from controlled areas without authorization.
• Wash thoroughly after handling radioactive materials.
• Immediately report spills, suspected contamination, or damaged radioactive-material containers.

Respiratory protection must only be used as part of an appropriate respiratory protection program when required.

Signs, Labels and Barricades

Radiation areas and radioactive materials may be identified with the radiation symbol and warning language such as CAUTION—RADIATION AREA or CAUTION—RADIOACTIVE MATERIALS.

Employees must:

• Observe all radiation signs, labels, barricades, and access restrictions.
• Never remove or bypass radiation controls without authorization.
• Keep required distances from radiation operations.
• Immediately report damaged, missing, or unclear radiation warnings.

Do not enter a restricted radiation area simply because no activity appears to be occurring.

Training and Authorization

Employees who work with ionizing radiation must receive appropriate training for their responsibilities and potential exposure.

Employees who are not trained or authorized to work with radiation sources should:

• Stay outside designated restricted areas.
• Follow posted warnings and instructions.
• Never handle radioactive materials or radiation-producing equipment.
• Notify supervision if they encounter an unidentified radiation source, damaged container, or unusual radiation-related condition.

Remember

Ionizing radiation cannot normally be detected by your senses. Never assume a radiation source is safe, shielded, or inactive based solely on appearance.

Minimize time, maximize distance, use appropriate shielding, obey radiation-area controls, and never enter a restricted area unless you are trained and authorized.