Hard hats are an essential piece of personal protective equipment (PPE) worn by workers in many industries to help protect their heads from impact, falling objects, and electrical hazards. LT is a common marking found on many hard hats that indicates the type and class of the helmet. Understanding what the LT stands for on a hard hat can help workers select the right hard hat for their specific work environment and safety needs.
Types of Hard Hats
There are different types of hard hats worn by workers, with the main types being:
Type I Hard Hats
Type I hard hats are designed to reduce force from blows to the top of the head. They have a full brim and are commonly worn in construction, mining, manufacturing, oil and gas, and other industrial work. Type I hard hats are designed to reduce impact from objects falling directly on top of the head.
Type II Hard Hats
Type II hard hats provide protection from blows to the top and sides of the head. They have a shortened brim compared to Type I helmets. Type II hard hats are commonly used by electrical workers as they offer dielectric protection from electrical hazards up to 20,000 volts. The design allows them to be worn backwards for tasks like climbing.
Hard Hat Classes
In addition to type, hard hats are also classified into different classes that indicate their level of protection:
Class G Hard Hats
Class G hard hats provide general impact protection from blows to the top or sides of the head. They offer the basic level of protection but do not protect against electrical hazards. Class G hats are typically Type I helmets used in construction, factories, and other sites with overhead hazards.
Class E Hard Hats
Class E hard hats provide protection from electrical hazards up to 20,000 volts in addition to impact protection. They are designed with non-conductive materials and are Type II helmets used by electricians, utility workers, and others at risk of electric shock.
Class C Hard Hats
Class C hard hats provide lightweight comfort and impact protection but offer limited voltage protection up to 2,200 volts. They are a compromise between Classes G and E for workers who need some electrical protection without the bulk of a full Class E helmet.
What Does LT Stand For?
With this background on hard hat types and classes, we can now understand what the LT marking indicates:
LT stands for Low Temperature.
LT hard hats are designed to maintain their impact protection and integrity in low temperature work environments. Standard hard hats can become brittle and prone to cracking at very cold temperatures.
LT hard hats contain special low temperature plastics or additives that make them more flexible and impact-resistant in cold conditions below -30°F. This makes them ideal for work in freezers, coolers, cold storage facilities, and outdoor winter work.
The LT marking is often combined with the type and class, such as “LT-I-E” for a Low Temperature, Type I, Class E hard hat. This identifies a low temperature rated helmet with full brim and electrical protection.
Choosing the Right LT Hard Hat
When selecting an LT hard hat, workers should consider:
- The coldest expected work temperature – LT hats come rated for different temperature minimums.
- The tasks being performed – LT helmets come in Type I or II for overhead versus electrical protection.
- The work environment hazards – Class G, E, or C as needed.
- Comfort features like padding or ratchet adjustment.
Following ANSI/ISEA and CSA standards, and choosing a hat rated for at least 10°F colder than the expected minimum temperature, helps ensure proper protection. Proper use and maintenance is also essential, as LT hard hats can become brittle over time when exposed to temperature swings.
Key Benefits of LT Hard Hats
Some key benefits that LT hard hats provide include:
- Maintain integrity and absorb impact at sub-zero temperatures.
- Reduce risk of brittle cracking or shattering of the shell in cold.
- Prevent helmet from freezing to users head in extreme cold.
- Comfort features like warm liners or pads tailored for cold environments.
- Higher temperature helmets can be worn over LT hats in extremely frigid conditions.
Having the proper cold rating and low temperature protection prevents hard hats from becoming a hazard themselves and allows them to continue protecting workers from falling objects, bumps, and electrical hazards even in freezing temperatures.
Industries That Use LT Hard Hats
Some industries and work environments where LT hard hats are commonly used include:
- Food processing, cold storage, and freezer facilities
- Commercial refrigeration and HVAC maintenance
- Chemical and pharmaceutical plants with cold processes
- Utility and energy work in cold climates
- Construction and maintenance of cold storage warehouses
- Oil and gas, mining, and drilling operations in cold regions
- Ski resorts and industries relying on snow and ice
- Winter road and bridge maintenance crews
- Emergency response in freezing weather
Any occupation that requires head protection while working in potentially sub-zero environments could benefit from having LT rated hard hats available.
Standards for LT Hard Hats
To ensure proper protection, LT hard hats are regulated by certain standards and certifications including:
- ANSI/ISEA Z89.1 – American national standard for protective headwear rating and performance.
- CSA Z94.1 – Canadian standard equivalent to ANSI Z89.1.
- ANSI/ISEA Z89.1-2009 – Updated standard that introduced LT and other ratings.
- ASTM F1446 – Standard test method for determining LT plastic integrity.
- CE EN 397 – European standard for industrial protective helmets.
Hard hats should be marked with the standards they meet and the temperature rating they were tested under to verify their LT rating is adequate. Accredited independent testing helps ensure compliance.
Proper Use of LT Hard Hats
While LT hard hats are designed to withstand cold environments, workers must still use and maintain them properly:
- Inspect for cracks, dents, or deterioration before each use.
- Replace suspension systems at least every 12 months.
- Avoid painting or applying unauthorized stickers or labels.
- Follow manufacturer cleaning instructions using mild soap and water.
- Store in temperatures above the minimum rating when not in use.
- Discard and replace any hard hat subjected to a heavy blow or damage.
Proper use and care ensures an LT hard hat maintains its cold weather performance over time. Workers should also receive training on proper fit, positioning, and wearing of hard hats specialized for cold environments.
Conclusion
The LT marking on hard hats indicates they are rated and specially designed for maintaining impact protection in low temperature conditions. LT hard hats keep workers safe in cold storage, processing, construction, maintenance, and many other occupations that require head protection in freezing environments. When selecting and caring for an LT rated hard hat, workers should review the temperature rating, class, type, and standards it is certified to meet to ensure adequate protection from both workplace hazards and extreme cold conditions. Proper use, fit, and care helps LT hard hats continue effectively protecting workers in cold weather and sub-zero environments.
