While agreeing with the above about how nice a little light the Petzl e+LITE is, I would like to point out that it is also ATEX approved for hazardous environments. From the Petzl e+LITE Technical Notice:

ATEX field of application
e+LITE is category 3 equipment that can be used in Zone 2 and Zone 22 where the explosive atmosphere may be present by accident: installation malfunction, leak.
Use is prohibited in Zone 0 and 20 and in and Zone 1 and 21.
Before using the lamp, take note of all hazardous areas you may enter.

CE Ex II 3GD Ex ic IIC T6
Ex tD A22 IP6x T85°C X
CE: CE marking.
Ex: use of the equipment in an explosive atmosphere.
II: group of equipment for surface use.
3: device for Zone 2.
G: gas environment.
D: dusty environment.
Ex: device fulfilling the requirements of the CENELEC standardization (European standards).
ic: intrinsic protection.
II: above-ground industry.
C: subdivision of gas including: acetylene, hydrogen, ethylene, carbon monoxide, butane, propane, ethanol.
tD: protection by enclosure.
A: European protection for IP.
22: zone 22.
IP6x: dust protection.
T85°C: maximum surface temperature of 85 °C.
X: WARNING DANGER, do not replace the batteries in an explosive atmosphere.
e+LITE has been certified by an independent laboratory (INERIS) as «equipment usable in a hazardous area» when used with the following batteries: Panasonic CR2032, Duracell DL2032, Akashi CR2032, Energizer CR2032, Renata DL2032.
Use only the batteries listed above in hazardous areas.
Maintenance
Water in the battery case can cause a malfunction. After use in a moist or wet environment, remove the batteries and allow the lamp to dry completely.