Protecting the eyes from hazards encountered during work, projects, or recreational activities is a serious concern. Since the eye is one of the body’s most vulnerable organs, protective eyewear must meet strict criteria to ensure effectiveness. The American National Standards Institute (ANSI) provides the foundational guidelines for this safety equipment in the United States. ANSI is a private, non-profit organization that coordinates the development of voluntary consensus standards, which serve as agreed-upon benchmarks for product performance across various industries. These standards ensure that safety products consistently deliver the expected level of protection against physical and environmental threats.
The Z87.1 Standard: Defining Eye Safety
The specific consensus standard governing eye and face protection is ANSI Z87.1, which applies to devices used in occupational and educational settings. This standard establishes minimum requirements for the design, performance, testing, and permanent marking of protective eyewear, including safety glasses, goggles, and face shields. It details the types of hazards the equipment must withstand, such as impact, non-ionizing radiation, and liquid splash exposures.
Compliance with the Z87.1 standard is often a regulatory requirement. The Occupational Safety and Health Administration (OSHA) mandates that employers provide eye and face protection that complies with ANSI standards, specifically referencing Z87.1. This adoption by OSHA elevates the standard, making it the legal benchmark for safety eyewear performance in many professional environments.
Classifications: Basic Versus High-Impact Protection
The ANSI Z87.1 standard defines two primary performance categories for impact resistance, which is central to most protective eyewear applications. The first category is Basic Impact, which involves testing the lens separately from the frame. For this test, a one-inch diameter steel ball is dropped onto the lens from a height of 50 inches to ensure the lens does not crack, chip, or break upon impact. While a lens must pass this initial drop ball test, this level of protection is generally considered the minimum requirement.
The more rigorous classification is High-Impact protection, which requires the entire protective device—the frame and the lens together—to withstand two different types of severe testing. The High-Velocity Impact test involves shooting a quarter-inch diameter steel ball at the eyewear at a speed of 150 feet per second. To pass, the lens must not fracture or dislodge from the frame, nor can the frame itself break. This test simulates the threat of fast-moving debris like ricocheting metal or wood chips.
The second measure is the High-Mass Impact test, which evaluates the device’s ability to resist a heavier, slower force. This test involves dropping a pointed, 500-gram weight from a height of approximately 50 inches onto the eyewear mounted on a head form. The eyewear must successfully prevent any pieces from breaking or fracturing, demonstrating its ability to protect against incidents like a dropped tool. Modern safety gear is overwhelmingly required to meet this higher standard of High-Impact protection.
Decoding Eyewear Markings
Consumers and safety managers can easily determine the level of protection provided by a pair of safety glasses by checking the permanent markings applied to the device. These markings are required to be clearly visible on both the frame and the lens. The core marking that indicates compliance with the Z87.1 standard is “Z87”.
A marking of “Z87” on its own signifies the eyewear has met the basic impact and optical requirements of the standard. When a plus sign is added, appearing as “Z87+”, it confirms that the device has passed the demanding High-Impact testing for both high-velocity and high-mass impacts. The manufacturer’s logo or name must also be present on the device to ensure accountability. Understanding the difference between “Z87” and “Z87+” is the most practical way to identify a suitable level of impact protection.
Specialized Protection Requirements
Beyond impact resistance, the Z87.1 standard establishes codes for protection against environmental hazards. These specialized codes are marked in addition to the base impact rating, allowing users to select appropriate task-specific gear. For protection against liquid hazards, the codes D3, D4, and D5 distinguish the level of protection offered by goggles or face shields. D3 indicates protection from liquid droplets and splashes, D4 is for defense against larger dust particles, and D5 denotes protection against fine dust.
Other specialized codes address different forms of radiation and light filtration. The letter U followed by a scale number indicates the level of Ultraviolet (UV) protection provided by the lens. Welding filters are denoted by the letter W and a shade number, which specifies the degree of filtering for visible light and infrared radiation. The letter L followed by a number signifies a visible light filter, common in tinted safety glasses used outdoors. These coded markings ensure that the eyewear is suitable for chemical handling, welding, or outdoor work.