The skin is the body’s largest organ, and protecting it from hazardous substances is a primary concern where chemicals are present. Unlike gloves designed for mechanical protection, chemical-resistant gloves must prevent toxic or corrosive materials from contacting the skin. The selection process is complex because no single glove material offers protection against every type of chemical. A material highly effective against one substance may quickly fail when exposed to another, making material selection the most important factor in hand protection.
Understanding Chemical Glove Failure
Chemical protective gloves can fail in three distinct ways when exposed to a hazardous substance. Permeation is the most concerning failure mode, occurring when a chemical passes through the intact glove material at a molecular level without any visible signs of damage. This process involves the chemical first being absorbed by the glove surface, diffusing through the material, and finally desorbing onto the inside surface where it contacts the wearer’s skin. Permeation is considered the most dangerous failure because the glove may look fine while the chemical is continuously passing through the barrier.
A second failure mode is degradation, which involves a physical change to the glove material upon contact with a chemical. Signs of degradation can include the material swelling, shrinking, becoming stiff, or cracking. While degradation is often the first visible indication of chemical incompatibility, it does not guarantee a specific breakthrough time, and failure can occur even before physical changes are noticeable.
The third mode, breakthrough time, is the standardized measurement of the time it takes for a chemical to be detected on the inside surface of the glove after initial external contact. This measurement indicates the duration a glove can theoretically be worn before the chemical begins to pass through. Testing for breakthrough time is reported in minutes, with a higher number indicating better protection for that specific chemical.
Key Materials and Their Chemical Strengths
Different glove materials are formulated to resist specific classes of chemicals, meaning the correct material must be matched precisely to the hazard. Nitrile gloves are a popular, general-purpose choice, offering good resistance to petroleum-based products, oils, greases, and many acids and caustics. However, they are not recommended for use with certain strong oxidizing agents, aromatic solvents, or ketones.
Neoprene gloves provide a wider range of protection against chemicals, including alcohols, organic acids, bases, and hydraulic fluids. Neoprene is a synthetic rubber that balances chemical resistance with good pliability and tear resistance, making it suitable for moderate exposure in laboratory or maintenance settings.
For highly aggressive solvents, Butyl rubber gloves are often necessary due to their superior resistance to highly corrosive acids, strong bases, aldehydes, esters, and ketones like acetone. Butyl rubber is also highly impermeable to gases, suitable for handling certain hazardous vapors. Conversely, butyl gloves perform poorly when exposed to aliphatic and aromatic hydrocarbons or halogenated solvents.
Viton gloves, a fluorocarbon elastomer, offer protection against the specific chemicals that challenge butyl rubber, such as aromatic and chlorinated solvents. Due to their specialized resistance, Viton is often used as a thin layer over other materials, like butyl, to create a highly protective laminated glove for the most aggressive chemical exposures. Vinyl (Polyvinyl Chloride or PVC) is typically reserved for low-hazard applications or splash protection, as it offers lower resistance and shorter breakthrough times against many common solvents compared to Nitrile or Butyl.
Selecting the Right Glove for the Job
The selection process moves beyond simply identifying the glove material and requires consulting chemical compatibility charts, which manufacturers provide based on standardized testing. These charts allow users to cross-reference the chemical they are using with the glove material to determine the expected breakthrough time and degradation rating.
Several environmental and operational factors significantly influence the effectiveness reported on these charts. For instance, an increase in the chemical’s concentration or the temperature of the environment can dramatically shorten the actual breakthrough time in the workplace. The duration of contact is also a major variable, as gloves intended only for intermittent splash protection will fail quickly if exposed to continuous immersion.
Glove thickness, often measured in mils, is another physical factor that directly impacts protection, as a thicker material correlates with a longer breakthrough time for the same chemical. However, tasks requiring fine motor skills or high dexterity may necessitate a thinner glove, which inherently sacrifices chemical resistance for greater touch sensitivity. The selection process is a trade-off that balances required protection level against the functional needs of the task.
Proper Use and Limitations
Regardless of the material chosen, the glove’s protective function relies heavily on proper usage and consistent protocols. Before each use, a thorough visual inspection is necessary to check for small tears, pinholes, or any signs of previous degradation like swelling or cracking. Even microscopic defects can allow a chemical to penetrate instantly, bypassing the intended barrier entirely.
Correct donning and doffing procedures are important to prevent skin contamination from the glove’s outer surface. The contaminated exterior must not touch the skin during removal, and hands should be washed immediately after doffing. Gloves must be stored away from extreme temperatures, sunlight, and ozone, as these elements can accelerate material aging and compromise the glove’s integrity.
It is important to recognize that many chemical-resistant gloves, especially those used for high-risk substances, are designed for single-use only. Even if a glove has a long manufacturer-rated breakthrough time, chemicals can remain absorbed within the material, making the glove unsafe for reuse due to the risk of delayed permeation. Adhering to the manufacturer’s guidance on reusability and disposal is a necessary safety protocol.