OSHA requires every worker to wear head protection if at least one of the following conditions are met at a worksite:
- Objects could fall from above to strike employees on the head;
- Employees could bump their heads against fixed objects;
- Someone’s head could come into contact with an electrical hazard.
Head protection varies for different jobs. Some are more specialized and rated better for particular jobs than others. ANSI rates helmets and hard hats by protection level and features. Types and classes of hard hats make it easier for you to find what you’re looking for—and we’ve broken it down to the basics.
Type I
These helmets and hard hats reduce the force of impact from a blow to the top of the head only—think of a tool falling from a higher level at a construction site.
Type II
These helmets and hard hats reduce the force of impact from a blow to the top or sides of the head. In addition to falling tools, consider exposed pipes, side beams, or other hazards.
Class C (Conductive)
These helmets and hard hats are not intended to protect against contact with electrical hazards. However, they may include venting and other options not available in helmets or hard hats that provide electrical protection.
Class G (General)
These helmets and hard hats are intended to reduce the danger of contact with low-voltage conductors and electrical hazards to the head only—they’re proof-tested at 2,200 volts.
Class E (Electrical)
These helmets and hard hats are intended to reduce the danger of contact with higher voltage conductors and hazards to the head only—they’re proof-tested at 20,000 volts.
Regardless of what type and class of helmet you need for the job, remember to get one that fits your hazards and your employee’s heads—look for chin straps and adjustable headbands for a secure fit. If high visibility is a priority, reflective striping or lights can be added for nighttime or extreme weather. Full brims are good for bright days and airflow vents for hot ones.
Always pay attention to the labels and manufacturer guidelines for the care, keeping, and disposal of your helmets and hard hats!
PK Safety has been your workplace safety partner for decades. Contact us online or by phone at 800-829-9580 with your questions about hard hats or safety workwear!
Frequently Asked Questions
What is the difference between Type I and Type II hard hats?
Type I hard hats are tested for impact protection from a blow to the top of the head only, per ANSI/ISEA Z89.1. Type II hard hats are tested for impact from both the top AND the sides (lateral impact), and must pass an off-center impact test that Type I helmets are not required to pass. Type I is common on general construction sites where falling-object hazards dominate. Type II is increasingly preferred where lateral impacts, moving equipment, low clearances, or fall hazards are present. Both types can carry any of the three electrical classes (E, G, or C).
What is the difference between Class E, Class G, and Class C hard hats?
The class rating describes electrical insulation performance per ANSI/ISEA Z89.1. Class G (General) hard hats are proof-tested at 2,200 volts phase-to-ground. Class E (Electrical) hard hats are proof-tested at 20,000 volts phase-to-ground with a leakage current limit of 9 milliamps. Class C (Conductive) hard hats provide no electrical insulation and are not tested for electrical performance — vented hard hats are always Class C by definition. Any Type I or Type II hard hat can be assigned any of these three classes.
Which OSHA standards require hard hats?
OSHA's core head-protection rules are 29 CFR 1910.135 for general industry and 29 CFR 1926.100 for construction, with parallel maritime standards for shipyards, marine terminals, and longshoring. For work near energized conductors, 29 CFR 1910.335 typically requires a Class E hard hat. OSHA doesn't publish its own performance specs — it requires head protection to comply with ANSI/ISEA Z89.1 (or be at least as effective). Employers determine the specific Type and Class for each role through a workplace hazard assessment under 29 CFR 1910.132.
Can vented hard hats be used for electrical work?
No. Vented hard hats are classified as Class C (Conductive) by definition — the ventilation holes disqualify the shell from receiving an electrical rating under ANSI/ISEA Z89.1. Class C hard hats provide no electrical insulation and are not tested for electrical performance. Where a workplace hazard assessment identifies potential electrical exposure, ANSI/ISEA Z89.1 requires a non-vented Class G hard hat (proof-tested at 2,200 volts) or Class E hard hat (proof-tested at 20,000 volts). OSHA 29 CFR 1910.335 typically requires Class E for work near high-voltage energized conductors.
When should a hard hat be replaced?
ANSI/ISEA Z89.1 and manufacturer guidance call for replacement immediately after any significant impact — even if no visible damage is apparent — because internal structural components may be compromised. For routine replacement, most manufacturers recommend replacing the shell every 5 years from the date of manufacture and the suspension (interior straps) every 1 to 3 years depending on use conditions. Every ANSI/ISEA Z89.1-compliant hard hat has a permanent marking inside the shell showing the manufacturer, standard, Type, Class, and date of manufacture; verify the specific replacement interval against the manufacturer's documentation.
What is the difference between a hard hat and a safety helmet?
Both terms cover industrial head protection under ANSI/ISEA Z89.1, but the distinction is becoming clearer as safety helmets gain adoption. "Hard hats" typically refer to traditional Type I designs (top-impact protection, with a chin strap as an option). "Safety helmets" typically refer to Type II designs (top + lateral impact protection, always with a chin strap and often with a foam liner). OSHA's 2024 Safety Helmet SHIB encourages employers to consider Type II designs where lateral impacts, falls, or moving equipment create multi-directional hazards. Type I remains OSHA-compliant where the workplace hazard assessment identifies primarily top-impact risk. Both categories must carry ANSI/ISEA Z89.1 markings to be OSHA-compliant.
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