The standard - UL 153 – previously only covered portable luminaires intended to be operated while connected to an external power source.
Through a supplement to the standard, UL 153 has now been expanded to include “portable luminaires intended to be operated while disconnected from any external supply source, with power provided only from integral single-use or rechargeable batteries,” UL Solutions said.
While the most common consumer product covered by the new supplement are flashlights, it also includes tabletop or wall-mounted luminaires.
To address the associated risks, the expanded standard includes requirements related to impact resistance, water ingress and photobiological hazards.
While lithium batteries are widely used in flashlights, many rechargeable lithium flashlights come with no safety certification.
“However, under certain conditions, lithium batteries’ very high energy densities pose risks of fire or explosion,” UL Solutions noted in a statement. “This concern increases for lithium batteries that may have design or manufacturing defects.”
The new supplement to UL 153 addresses this lack of safety certification “by specifying an appropriately targeted evaluation program that can be performed by independent test agencies” and by requiring lithium battery cells “to comply with the relevant requirements in UL 1642, the Standard for Lithium Batteries, or UL 62133-2, the Standard for Secondary Cells and Batteries Containing Alkaline or Other Non-Acid Electrolytes.”
The supplement also verifies that the charge and discharge conditions offered by the flashlight meet the battery manufacturer’s recommendations.
The UL 153 supplement requirements also limit the operating voltage of flashlights “to prevent the risk of electric shock injury in wet environments” and limit the overall battery power “to reduce the risk of fire and high surface temperatures.”
It also requires a photobiological evaluation to test the impact of the flashlight on the human eye.