Start with the standard your site or tender names. IS 2925:1984 is the Indian standard for industrial safety helmets, and Karam lists the ISI mark on most of its IS 2925 models. EN 397 is the European standard for industrial safety helmets. For electrical work, look at the helmets Karam also states to EN 50365:2002, the European standard for electrically insulating helmets used on low voltage installations: PN542, PN541(NS), PN545(NS), PN561 and PN581. The PN574 is stated to the American ANSI/ISEA Z89.1-2014 Type 1, Class G and E, where Type 1 covers blows to the top of the head and G and E are its electrical classes.
Then choose the shell. Peak helmets have a short front brim, while the peakless PN545 and PN546 families leave the view upwards clear. Most Karam helmets here are polypropylene co-polymer with dual, triple or quadro corrugation (moulded ribs that stiffen the shell) and increased vertical clearance, the gap between head and shell that helps absorb a blow. The ventilated models have slots with a shutter you can close against rain; the PN571 has open ventilation holes and an ABS shell, FT11 and FT15 are non-vented, and FT01 has a triple ribbed HDPE shell.
Next, the fit. A slider or nape adjustment is set by hand, a ratchet is tightened by turning a knob at the back, and a pin-lock uses a pin set into a row of holes. Y type chin straps (the YTC models and the Aironic PN629AC) hold the helmet on more securely, and a textile cradle (PN561(T), PN581(T), PN571, PN574) replaces plastic straps inside with breathable fabric. PN501, PN521, FT11 and FT15 have slots for face shields or ear muffs.
For heat, the Aironic helmets carry an active cooling unit for work areas at 40°C to 60°C, run on a rechargeable li-ion battery and can also switch to heating. A bump cap such as the PN595 (EN 812:2012) only guards against knocks on fixed objects and does not replace a safety helmet where things can fall. Prices are on request: call or WhatsApp +91 92440 89060.