Sodium Lamps
Sodium lamps come in high pressure and low-pressure versions. Both versions work by creating an electric arc through vaporized sodium. These lamps are often found in street lighting. Low-pressure sodium lamps, also known as SOX lamps, have a distinct yellow color. They are very efficient and powerful, and unlike LEDs, the lumen output does not decrease over time. However, the sodium inside the bulb is a hazardous material and can explode if broken. High-pressure sodium lamps were invented in order to increase the efficiency of the lamps.