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What Is a Class 4 Laser?

Laser classifications can be confusing, especially if you are looking for tools to improve your practice. These categories describe the influence the laser has on the surrounding environment, including the risks to patients and technicians. A Class 4 laser is the most powerful in terms of impact.

This strength allows a Class 4 laser to penetrate deeper to stimulate healing and reduce pain and swelling. Understanding how a Class 4 laser differs from the other categories will help practitioners and decision-makers choose their laser products wisely. This article provides valuable insight into Class 4 lasers and their therapeutic benefits.

What Is a Class 4 Laser?

Class 4 is currently the highest classification for a laser. The power output for a Class 4 device is greater than 500 mW, compared to a Class 3 laser, which has a power output between 5 and 500 mW.

A Class 4 laser is photothermal. The beam heats what it touches, so using it requires stringent safety practices.

All laser use requires safety precautions for the technicians and the patients. However, a Class 4 laser takes those requirements to the next level. It must be in a well-ventilated location, and anyone near the laser would require protective eyewear. This heightened level of safety underscores the importance of responsible laser use.

How Does a Class 4 Laser Work?

A Class 4 laser's wavelength can penetrate deeper into the body. The tissue absorbs the light from the laser, creating chemical reactions within the cells that stimulate healing. The high power of a Class 4 laser means the penetration is deeper than that of other classifications.

Even though a Class 4 laser has a photo-thermic effect, the patient feels nothing but a warming sensation. Their treatment is non-invasive and painless. It stimulates healing and reduces inflammation even in areas deep within the body.

What are Class 4 Lasers Used For?

Class 4 laser therapy can be a surgery-free answer to treating some medical issues, such as:

  • Sports injuries
  • Chronic pain
  • Rheumatoid arthritis pain
  • Osteoarthritis pain
  • Plantar fasciitis
  • Fibromyalgia pain
  • Disc issues
  • Pinched nerves

The treatment can stimulate healing and improve a patient's range of motion. Its side effects are also minimal.

Class 3 vs Class 4 Laser

Generally speaking, laser classifications focus on how the laser affects what it touches. According to Lawrence Berkeley National Laboratory, the impact comes from:

  • Output energy
  • Radiation wavelengths
  • Duration of exposure
  • Beams cross-sectional area at the point of interest

The accessible emission limit (AEL) is also a critical parameter. The higher the classification, the greater the impact of the laser.

Beyond power output, the most significant difference between a Class 3 vs Class 4 laser is how it affects the tissue. Class 3 lasers are non-heating.

During treatment with a cold laser, light energy interacts with chemical elements in the cells called chromophores. This interaction results in changes to the tissue at a cellular level that accelerates healing and tissue growth.

Class 4 lasers are photothermal, which means they produce heat. The high-power design allows the light to penetrate deep into the tissue, reaching areas where the Class 3 laser won't, passing energy to critical nerves and tissues.

Are Class 4 Lasers Safe?

The high power output and thermal nature of Class 4 lasers make them more of a safety concern. As with all laser products, they are subject to Food and Drug Administration (FDA) regulations.

Some safety requirements that apply to Class 4 lasers include:

  • Safety warning signs: Specific ANSI-approved signs must be in place for any practice operating a Class 4 device. The signs warn that the area is Class IV Laser Controlled and provide warnings distinctive to this classification. The signs must be easily seen in and outside the room that holds the laser.
  • Eye protection gear: Protective eyewear is required for Class 3 and Class 4 lasers, as they emit visible and invisible radiation. Everyone in the room, including the treatment practitioners and the patient, must have protective eyewear. In addition, the eyewear must be designed to match the wavelengths of the laser device. Get eyewear protection from the laser manufacturer to ensure it provides the right level of security. Also, keep extra eyewear outside the room in case someone needs it.
  • Reflection control: You must manage all potential sources of reflection and light scatter inside the room.

Protocols must also be followed before a Class 4 laser treatment begins. Technicians must inspect all optical connectors for dirt and debris that might become fire hazards. In addition, there should be a plan to manage injuries in case of an accidental burn.

All businesses that use lasers must designate a Laser Safety Officer (LSO). This person will undergo additional training to ensure the proper protocols are in place to reduce the risks. This helps keep patients and staff safe when a Class 4 Laser is used.

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