Chemical-resistant gloves are important when working with chemicals. The Safety Data Sheet (SDS) is often the first place people go to find glove recommendations however most SDS’s provide generic or incomplete information glove selection. That is when you’ll have to refer to a glove manufacturers test chart. The test data is generally from a laboratory environment and with one specific chemical. Glove manufacturers generally do not test chemical mixtures and don’t consider other variables in your application, such as hot or cold temperatures and cut hazards. Below are chemical guide links for some of the larger glove manufacturers selection charts:
On these chemical-resistance guide charts, you will find gloves made from many different materials. Different glove materials can react differently to individual chemicals. An important consideration when choosing a protective glove for working with chemicals is how the specific chemical reacts with the glove material. A SDS that only specifies an acid-resistant glove is misleading because one glove material might work fine with hydrochloric acid, but provide little or no protection from nitric acid. Gloves are generally tested and rated in three categories for chemical compatibility: degradation, breakthrough time and permeation rate. All three should be considered when selecting a glove.
Degradation is a change in physical properties of the glove material. Common effects include swelling, wrinkling, stiffness, change in color or other physical deterioration. The degradation ratings indicate how well a glove will hold up when working with a specific chemical. Degradation tests vary by manufacturer. There is no standardized test that is used by everyone in the industry. However, the glove material usually has constant exposure to the test chemical and the percent weight change is then determined at time intervals.
Degradation is one critical factor when choosing a glove but other considerations are chemical breakthrough time and the permeation rate of the glove with the chemical. Degradation is usually the first test. Most manufacturers do not test permeation or breakthrough time if the chemical causes significant degradation to the glove material. Degradation alone can be enough to disqualify a glove for use with a chemical.
Breakthrough time is the elapsed time between initial contact of the chemical on one side of the glove material and the analytical detection of the chemical on the other side of the glove material. This test is conducted per ASTM F739 standard test method for resistance of protective clothing materials to permeation by hazardous liquid chemicals. The higher the result, the longer it takes for the chemical to pass through the glove material. The actual time reported on the chemical is usually listed on the compatibility charts. If breakthrough did not occur, the data reported is typically ND (none detected) or > (greater than) the indicated test period. The times generally reflect how long a glove can be expected to provide resistance when totally submerged in the test chemical.
Permeation rate is a measurement that describes the rate of a chemical passing through the glove material at the molecular level. This process is similar to how a balloon loses air after enough time passes even though it is still tied and has no visible holes. The thickness of the glove can greatly affect the permeation rate.
Manufacturers report permeation rate in different ways. Some report in micrograms of chemical per square centimeter of glove material per minute. The higher the result, the more of the chemical that passes through the glove material. Other manufacturers rate the permeation similar to that done for degradation: excellent (E), good (G), fair (F), poor (P) and not recommended (NR). If chemical breakthrough does not occur, permeation is not measured. This is reported as ND (none detected) or NT (not tested), depending upon the manufacturer. This test is also conducted per ASTM F739.
If you want more information on PPE assessments or training contact Trevor Reschny. 407-760-6107 or email him at treschny[at]safetylinks.net