Intrinsically Safe Lights
Understanding Intrinsic Safety
Some work environments are considered Hazardous Locations (HAZLOC): "where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings."
If you bring a flashlight into a Hazardous Location, you must be sure it has been tested and rated safe to use under those conditions or you risk to ignite a fire and cause an explosion. Lights that carry these ratings are certified Intrinsically Safe.
The US and Europe have different criteria for their safety certifications, read below to learn more.
US & Canada Certifications
The US and Canada Certify Lights Based On Criteria Below
In order to understand the rating printed on a flashlight let us look at the rating on the side of our 4AA eLED RFL light as an example.
(Note: a light is not certified unless the mark of certification is printed on the light.)
In the US and Canada, all Intrinsically Safe flashlights are rated Division 1.
DIVISION 1 : Hazard Likely". This is a location where an ignitable concentration of flammable material is present under normal operation conditions.
DIVISION 2 : "Hazard Not Likely". This is a location where an ignitable concentration of flammable material is present under abnormal conditions, but where a fire or explosion could occur.
All Intrinsically Safe flashlights are rated Division 1.
This rating is further broken down into Classes, which depend on the type of flammable material the flashlight might encounter.
CLASS 1 : Flammable gases, vapors, and liquids - for instance petroleum refineries, utility gas plants, gasoline storage facilities etc.
CLASS 2 : Combustible dusts - for example grain elevators, coal preparation plants, etc.
CLASS 3 : Ignitable fibers and flyings - for instance textile mills or plants that create sawdust
Each Class is then broken into Groups to further classify hazard materials that have similar characteristics, more importantly their ignition-related properties.
GROUP A: Acetylene
GROUP B: Acrolein, arsine, butadiene, ethylene oxide, propylene oxide, propylnitrate, hydrogen
GROUP C: Acetaldehyde, allyl alcohol, n-butyraldehyde, carbon monoxide, crotonaldehyde, cyclopropane, diethyl ether, diethylamine, epichlorohydrin, ethylene, ethyl ether, ethylenimine, ethyl mercaptan, ethyl sulfide, hydrogen cyanide, hydrogen sulfide, morpholine, 2-nitropropane, tetrahydrofuran, and unsymmetrical dimethyl hydrazine.
GROUP D: Acetic acid (glacial), acetone, acrylonitrile, ammonia, benzene, butane, 1-butanol (butyl alcohol), 2-butanol (secondary butyl alcohol), n-butyl acetate, isobutyl acetate, di-isobutylene, ethane, ethanol (ethyl alcohol), ethyl acetate, ethyl acrylate (inhibited), ethylene diamine (anhydrous), ethylene dichloride, ethylene glycol monomethyl ether, gasoline, heptanes, hexanes, isoprene, isopropyl ether, mesityl oxide, methane (natural gas), methanol (methyl alcohol), 3-methyl-1 butanol (isoamyl alcohol), methyl ethyl ketone, 2-methyl-1-propanol (isobutyl alcohol), 2-methyl-2-propanol (tertiary butyl alcohol), petroleum naphtha, pyridine, octanes, pentanes, 1-pentanol (amyl alcohol), propane, 1-propanol (propyl alcohol), 2-propanol (isopropyl alcohol), propylene, styrene, toluene, vinyl acetate, vinyl chloride, xylenes
GROUP E: Combustible metal dusts, including aluminum, magnesium and their commercial alloys
GROUP F: Carbonaceous dusts, including coal, carbon black, charcoal and coke
GROUP G: Dusts not included in Groups E and F, including wood, plastics, flour, starch, grain or chemical dusts
Finally, as a double check, the flashlight it is given a “T” rating, which is based on the highest temperature any part of the flashlight can reach while in use or when something goes wrong like a short circuit in the light.
EUROPEAN CERTIFICATIONS (ATEX)
Europe Uses Different Standards For Certification Testing
In order to understand the rating printed on a flashlight let us look at the rating on the side of our 3AA eLED CPO light as an example.
Intrinsically Safe industrial flashlights are rated for Groups II & III
Group I: Electrical equipment intended for use in mines susceptible to firedamp (methane)
Group II: Electrical equipment intended for use in places with an explosive gas atmosphere other than mines susceptible to firedamp (methane)
Group lII: Electrical equipment intended for use in places with an explosive dust atmosphere other than mines susceptible to firedamp (methane)
Intrinsically Safe flashlights should be rated at least CATEGORY 1 or 2
1 (zone 0, 20): Explosive gas/dust present continuously or most of the time (>1000 hr/year) (NEC Div 1 equivalent)
2 (zone 1, 21): Explosive gas/dust present occasionally (10-1000 hr/year) (NEC Div 2 equivalent)
3 (zone 2, 22): Explosive gas/dust unlikely to occur or present for short periods only (1-10 hr/year) (NEC Div 2 equivalent)
Gas rating is required
i Intrinsic safety protection is most efficient
i Intrinsic safety / e Increased safety / n Non-arcing / d Flameproof
q Powder filled / n Enclosed or sealed / p Purged or pressurized / m Encapsulation
n Restricted breathing / o Liquid immersion / t dust protected / op is limited optical energy
a or b engineering analysis is required
a Two fault analysis (Cat 1, zone 0, 20)
b One fault analysis (Cat 2, zone 1, 21)
c Normal operation (Cat 3, zone 2, 22)
Specifies the most flammable Atmosphere Group where the light can be used
Group I: I typical gas: methane
Group II: IIA typical gas: propane (NEC Class I, Group D) IIB typical gas: ethylene (NEC Class I, Group C) IIC typical gas: hydrogen (NEC Class I, Group A & B)
Group III: IIIA material: combustible flyings (NEC Class III) IIIB material: non-conductive dust (NEC Class II, Group F, G) IIIC material: conductive dust (NEC Class II, Group E)