Glossary
Abrasion:
The physical rubbing or scraping of a protective clothing item by an abrasive rotary wheel determines the length of wear based on the number of cycles till the polymer coating is worn through. This term is useful in measuring how long a glove will wear or how well it will hold up when handling abrasive objects.
Absorption:
The first step in permeation. The chemical substance is absorbed onto the surface of the protective clothing.
Analytical test method:
The method used to measure permeation. Different chemicals require different methods of detection such as gas chromatography for most volatile organic solvents.
ANSI/ISEA 105:
American National Standard for Hand Protection Selection Criteria: This standard provides the performance based ranking system for maximizing hand protection to reduce hand injuries. It utilizes existing ASTM, ISO or EN Standards and assigns a performance rating based on the results of testing utilizing standards from various worldwide technical safety organizations.
ASTM F1001:
Standard Guide for Selection of Chemicals to Evaluate Protective Clothing Materials: This standard established a list of recommended chemicals to test the chemical resistance properties of protective clothing chosen because they are from a broad range of chemical classes. These include both liquids and gases:
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ASTM F1383:
Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Intermittent Contact. This method simulates limited contact with chemicals rather than full constant immersion.
ASTM F739:
Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact. This method simulates constant total immersion in the test chemical for eight full hours, the worst case exposure.
Breakthrough Time:
The number of minutes from initial contact with a test chemical until it is first detected on the inside of the protective clothing measured using sensitive analytical testing. It is essentially the number of minutes until your skin is exposed inside the gloves or other protective clothing.
Butyl:
This is a synthetic manmade rubber copolymer made from the two polymers isobutylene and isoprene. It is used extensively in tire inner tubes since it is airtight. The main classes where Butyl Rubber provides excellent chemical resistance are gases including nerve agents, ketones and other polar aprotic solvents.
Carcinogen:
Human Carcinogen: There is enough evidence that the International Agency for Research on Cancer deems the chemical a human carcinogen.
CAS Number:
The Chemical Abstract Services Registry Number is a universal identifier unique to each chemical substance. A CAS Registry Number is separated by hyphens into three parts, the first consisting of up to 7 digits, the second consisting of two digits, and the third consisting of a single digit. A chemical may have numerous different names but only one CAS Number.
Class:
ASTM F 1186 Standard Classification System for Chemicals According to Functional Groups: This standard classification system by functional groups uses a three-digit code.
Collection Medium:
The medium on the collection side of a permeation test cell designed to collect the analyte being measured as it permeates through the protective clothing from the challenge side of the test cell. The collection medium may also serve as the carrier gas in gas chromatography such as Nitrogen or as the mobile phase solvent in HPLC or as the water in pH or Conductivity testing.
Concentration:
The amount or mass of a constituent divided by the total mass of a solution. Normally all Organic Solvents tested in this site are 100%. Acids and Caustics are solutions in water. In permeation testing of acids, in particular, the concentration will affect the breakthrough time. More concentrated acids will permeate sooner than dilutions.
Conductivity:
In permeation testing, one Analytical Test Method that is useful in certain kinds of chemicals measures the ionic disassociation of the chemical where deionized water is the collection medium. A Conductivity meter is the detector and may be useful for salt or some acids and caustics testing.
Cut Resistance:
1. ASTM F 1790 Standard Test Method for Measuring Cut Resistance of Materials Used in Protective Clothing. This method measures the rating force in grams required to cut through the protective clothing with a blade travel or reference distance of 20 mm.
Cut Resistance:
2. EN 388 Protective Gloves Against Mechanical Risks: This method uses a constant load of 500 grams and measures the performance index based on the number of cycles to cut through the material relative to a reference material.
The deleterious change in one or more physical properties of a protective clothing material due to contact with a chemical. Showa Best Glove uses the swell of the glove material measured by weight change after immersion in the test chemical measured at 5, 30, 60 and 240 minutes. The gravimetric rating system used is:
- E: Excellent or <10% weight change
- G: Good or 10 to 20% weight change
- F: Fair or >20% to 30% weight change
- P: Poor or >30% to 50% weight change
- NR: Not Recommended or >50% weight change (severe degradation)
Other degradation changes may include delaminating, discoloration, hardening, loss of tensile strength
Diffusion:
The second phase of permeation. The molecular passage of a chemical through the protective clothing material. It can be affected by the thickness of the material and the temperature conditions or temperature of the chemical.
EN 374:
Protective Gloves Against Chemicals and Micro-organisms. The standard established by Comité Européen de Normalisation. This standards committee represents numerous countries worldwide with normative standards for worker protection. Permeation Performance Levels are as follows:
Measured Breakthrough Time: |
Permeation Performance Level: |
<10 minutes |
0 |
>10 minutes |
1 |
>30 minutes |
2 |
>60 minutes |
3 |
>120 minutes |
4 |
>240 minutes |
5 |
>480 minutes |
6 |
To attain the EN374 pictogram shield gloves must pass at least a Level 2 in 3 chemicals from the list below: |
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Code Letter |
Chemical |
Code Letter |
Chemical |
A |
Methanol |
G |
Diethylamine |
B |
Acetone |
H |
Tetrahydrofuran |
C |
Acetonitrile |
I |
Ethyl Acetate |
D |
Dichloromethane |
J |
Heptane |
E |
Carbon Disulfide |
K |
Sodium Hydroxide 40% |
F |
Toluene |
L |
Sulfuric Acid 96% |
If gloves have some chemical resistance but not to these specific chemicals it may be labeled with the pictogram that indicates waterproof with low chemical resistance |
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EN 388:
Protective Gloves Against Mechanical Risks. The standard established by Comité Européen de Normalisation. This standards committee represents numerous countries worldwide with normative standards for worker protection. This standard establishes test methods and performance levels for protection from physical hazards or mechanical risks as follows.
Test |
Level 0 |
Level 1 |
Level 2 |
Level 3 |
Level 4 |
Level 5 |
Abrasion Resistance (cycles) (A) |
<100 |
100 |
500 |
2000 |
8000 |
- |
Blade Cut Resistance (index) (C) |
<1,2 |
1,2 |
2,5 |
5,0 |
10,0 |
20,0 |
Tear Resistance (N) (T) |
<10 |
10 |
25 |
50 |
75 |
- |
Puncture Resistance (N) (P) |
<20 |
20 |
60 |
100 |
150 |
- |
The EU Directive mandates that the mechanical pictogram for EN 388 with the numeric performance ratings for (A) Abrasion, (C) Cut Resistance, (T) Tear Resistance and (P) Puncture resistance must be on every glove sold in the member countries in Europe.
European Risk Category:
Toxicity Label required by the European “Guide to Classification and Marking of Hazardous Substances” labeling ordinance as follows:
European Risk Category |
European Risk Code |
1. Extremely Toxic |
Very Toxic………………………………………….Tx |
2. Highly Toxic |
Toxic…………………………………………………..T |
3. Moderately Toxic |
Corrosive………………………………………………C |
4. Slightly Toxic |
Potentially Harmful |
European Risk Code:
Dangerous Substances Directive (67/548/EEC) is a European law concerning the labeling of chemicals and includes:
Tx: Very Toxic |
X: Harmful |
T: Toxic |
SENS: Allergen or Known Sensitizer |
CX: Highly Corrosive |
CANCER: Suspected Carcinogen |
CANCER: Known Carcinogen |
V: Low Toxicity |
C: Corrosive |
n.a.: No Risk |
Extreme Hazard:
A substance appears on the US Environmental Protection Agency list of Extremely Hazardous substances because of its flammability or toxicity and potential to cause a catastrophic event.
Gas Chromatography:
Analytical Test Method for Volatile Organic Compounds (VOCs) that employs a column packed with inert material that separates the test chemical into different components in a heated oven. Various analytical detectors such as Electron Capture (ECD), Flame Ionization (FID) or Photoionization (PID) may be employed depending on which is best suited for detecting the analyte of concern. Most Organic Solvents can be analyzed using FID or PID detection with the most uniform response factors across a relatively broad range of concentrations. In permeation testing, the permeation test cell containing the protective clothing material is sandwiched between the challenge side which is immersed in the test chemical when the test is started. The collection side of the test cell has inert carrier gas such as Helium or Nitrogen flowing at a constant rate which is sampled and injected into the gas chromatograph. As the chemical breaks through a peak is drawn and the breakthrough time is detected.
Heavy Exposure:
In permeation testing this term refers to constant total immersion of the protective clothing material in the test chemical which represents the worst type of heavy exposure. The ASTM F 739 Test Standard and EN 374 European Test Standard refers to this type of exposure.
HPLC: High Pressure Liquid Chromatography:
This Analytical Test Method is for chemicals that are not volatile enough to be tested using Gas Chromatography. A mobile phase which is normally some solvent or solvent mixture is pumped through columns under pressure at a constant flow. Normally samples are taken from the collection side of the permeation test cell and injected into the HPLC which flows into the detector that detects when an analyte has broken through.
Intermittent Exposure:
ASTM F 1383 Standard Test Method for Permeation of Liquids or Gases through Protective Clothing Materials under Conditions of Intermittent Contact. Showa Best Gloves used a contact time of 1 minute where the glove material was fully immersed and 9 minutes of purge time where the glove material was unexposed to the chemical which was repeated for 240 minutes.
Minimum Detectable Limit:
Measure of the sensitivity of the analytical system usually given in parts per million (ppm).
Neoprene: This is the DuPont registered trade name for synthetic rubber polymer Polychloroprene. Neoprene is ideally suited for handling acids and caustics
NFPA: National Fire Protection Agency:
This American Agency is responsible for NFPA 704 that defines the “fire diamond” which shows Health, Flammability and Reactivity.
NFPA Flammability:
National Fire Protection Agency Flammability Ratings 0, 1, 2, 3 or 4 where
- NFPA Flammability Rating 0: Will not burn
- NFPA Flammability Rating 1: Must be heated before ignition can occur to over 93°C (200°F)
- NFPA Flammability Rating 2: Must be moderately heated or exposed to relatively high ambient temperature
before ignition can occur Flash point between 38°C (100°F) and 93°C (200°F)
- NFPA Flammability Rating 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Liquids having a Flash point below 23°C (73°F) and having a Boiling point at or above 38°C (100°F) or having a Flash point between 23°C (73°F) and 38°C (100°F)
- NFPA Flammability Rating 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily below 23°C (73°F)
NFPA Health:
National Fire Protection Agency Health Ratings 0, 1, 2, 3 or 4 where
- NFPA Health Rating 0: Poses no health hazard, no precautions necessary (e.g. Water)
- NFPA Health Rating 1: Exposure would cause irritation with only minor residual injury (e.g.,Acetone)
- NFPA Health Rating 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury (e.g., Ethyl Ether)
- NFPA Health Rating 3: Short exposure could cause serious temporary or moderate residual injury (e.g., Chlorine Gas)
- NFPA Health Rating 4: Very short exposure could cause death or major residual injury (e.g., Hydrogen Cyanide, Phosphine, Carbon Monoxide)
NFPA Reactivity:
National Fire Protection Agency Reactivity Ratings 0, 1, 2, 3 or 4 where
- NFPA Reactivity Rating 0: Normally stable, even under fire exposure conditions, and is not reactive with water
- NFPA Reactivity Rating 1: Normally stable, but can become unstable at elevated temperatures and pressures
- NFPA Reactivity Rating 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water
- NFPA Reactivity Rating 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked
- NFPA Reactivity Rating 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures
Nitrile:
This is a synthetic manmade rubber polymer made from the two monomers Acrylonitrile and Butadiene. This copolymer is ideally suited for handling fuels and aliphatic hydrocarbons.
Normalized:
Normalized or standardized in reference to permeation testing refers to standardizing the breakthrough time to when the permeation rate has reached 0.1 micrograms/square centimeter/minute (µg/cm2/min) for ASTM F739 and F 1383 test methods and to 1.0 µg/cm2/min for EN 374 standard
Penetration:
The process by which a substance moves through a closure, seam or pinhole in protective clothing on a non-molecular level.
Permeation:
The process by which a chemical moves through protective clothing materials at the molecular level. The passage of a liquid or gas through protective clothing consists of three steps, adsorption, diffusion and desorption.
Adsorption:
The chemical substance is absorbed at the surface of the protective clothing.
Diffusion:
The chemical substance permeates though molecular gaps in the polymeric matrix of the protective clothing
Desorption:
The chemical vapors leave the chemical protective clothing on the inside and exposure to the chemical occurs.
Permeation Rate:
The rate in micrograms per minute per surface area of the protective clothing. It is given in µg/cm2/min for ASTM F739 and F 1383 test methods and is not required for reporting in the EN 374 Test Method.
pH:
In permeation testing of acids and caustics, pH can be used is used as the method of detection for when breakthrough occurs. Pure water is said to be neutral, with a pH close to 7.0. Acid solutions have a pH less than 7 while solutions with a pH greater than 7 are basic or alkaline. Substances that are soluble and not reactive with water cam be tested for permeation using water as the collection medium with pH as the measure for when breakthrough occurs.
Polymer:
A large molecule or macromolecule made up of polymerized units or monomers. Some elastomeric polymers are vulcanized with the addition of sulfur which forms bridges or cross-links where double bonds have been in the polymer chain to form very large chains that exhibit elastomeric properties of stretch and rebound.
Puncture Resistance:
ASTM F 1342 Standard Test Method for Protective Clothing Material Resistant to Puncture is the ASTM test method which uses a nail-like object and measure the force. EN 388 Utilized a nail-like object and measures the force in Newtons to puncture through a test specimen.
PVC:
Poly Vinyl Chloride is a thermoplastic polymer made from PVC Resins and plasticizers that are heated till fusion occurs of the resins and plasticizers where PVC Resins provide the strength and the plasticizers provide the softness and flexibility of chemical resistant gloves. PVC is known for exceptional durability and is economical.
Skin Notation:
The American Conference of Governmental Industrial Hygienists has determined that a chemical can be absorbed through intact skin and can contribute to the overall toxic effects of the chemical.
Steady State:
This term related to permeation testing and reporting refers to the constant steady state is the rate in micrograms/minute permeating a surface area in square centimeters when the rate of passage reaches equilibrium during the eight hour test period for ASTM F 739 permeation test method. Steady State rate isnot reported in EN 374 European Test Method.
Synonym:
Some chemicals may have numerous chemical names from trade names to slang names to IUPAC Names. All of these are the same chemical, but called by different names. All can be identified by the CAS Number (see above). IUPAC is the International Union for Pure and Applied Chemistry and determines the nomenclature used in establishing the numbering and order for each functional group within a substituted compound.
Tear Resistance:
EN 388 Utilizes the tear strength in Newtons is the force used to propagate a tear in a rectangular specimen slit half way along its length. It is not reported in ANSI 105 American National Standard for Hand Protection Selection Criteria
Thickness:
In protective clothing, the thickness is the measurement in mils or thousandths of an inch or in mm. Normally thickness measurements are only used in disposable and unlined Chemical Resistant Gloves. The permeation breakthrough time is longer in thicker gloves.
Toxicity:
Is the degree to which a substance can damage a living or non-living organisms. It can have many different implications depending on the target organ, acute toxicity or long term chronic toxicity and the degree of toxicity or carcinogenicity.
Viton:
This is the brand name of DuPont and represents a class of synthetic polymers made up of copolymers of Hexafluoropropylene and Vinylidene Fluoride. The main chemical classes where Viton gloves provide excellent protection include halogenated hydrocarbons and aromatic hydrocarbons.
ND:
None Detected means that for the entire length of time of the permeation test no chemical was detected on the inside so no permeation occurred.
NR:
Not Recommended because of severe degradation