mfety in the chernicol loboratory
edited by MALCOLM M. RENFREW University of Idaho Moscow. Idaho 83843
Selecting Chemical Protective Gloves Properly in the Lab Charles Halt Department of Environmental Health & Safety, Hudson Health Center, Ohio University, Athens, OH 45701 Gloves are often used to prevent expwure c. Contact your environmental health 1. Outline the procedures to he used. to chemicals and other materials that may How is chemical contact with the and safety staff. come in contact with the skin. While gloves gloves likely to afcur? 4. Outline how often and how long (in minare an important protective measure, prop2. ~ ithe~ t for protection utes!) the gloves will he worn for proer selection and use is imperative. There are tection. How long will the chemical ar is sought. many types of "rubber" gloves and many mixture be in contact with the gloves? 3. Review the effects of these chemicals different types The type of on the skin, their toxicity, are they skin When you have gathered your informaglove material must he carefully matched to absorbable, etc. tion and are ready to select some gloves, yon the chemical and use situation. Normal disa. Obtain an MSDS (material safety KU need to he familiar with two coneposahle latex lab gloves are not appropriate data sheet) from the chemical epts. . .permeation rate and breakthrough in many situations. The choice of the wrong plier. time. Permeation rate (PR) is the rate a t glove material could result in chemicals perh. Check reference books. (Continued on page A180) meating the glove and contacting the skin within as little as 5 min! First of all, personal protective equipment such as gloves shouldgenerally be the last resort in any attempt to control an environmental hazard. Other control measures such as substitution with safer chemical! procedural changes, ventilation or other en gineering controls, etc., should always b considered first. If, after careful consider ation, other control methods are felt to h impractical and gloves are necessar) "choose and use" them properly. Gloves ar often used as an adjunct with other method of control for extra protection as well. Initially, review the purpose for the glove and the work prafesses and practices tha ChemService, Inc. now offers the necessary will he used.
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Charles Hart received a BS in Environmental Heath from Cleveland State University in 1976 and an MA in Health 8 Safety Education from Kent State University In 1980. He is a Reoistered Sanitarian IRS) and an ABlH Certiflea lndusuial Hygenlst (CIHI, hsvlng * d e d !n environmental sanltatlon. epidemiology. and o~blcandoccupational health slnce 1976 For me last five years he has held me position of environmental safety rowdinator at Ohio University. Dgpartment of Environmental Health & Safety, Athens, Ohio: hsvlng responsibilities in occupational safety, Industrial hygiene, arm bioaafety. He is a member of numerous profer sional organizations in the areas of idustrial hygiene, biosafety, environmental health, and campus safety.
chemicals for conducting 52 lab experiments as outlined in "Microscale Organic Laboratory" by Mayo, Rike and Butcher. The chemicals are high-purity compounds, provided in quantities of 30-50% greater than listed in the laboratory manual. All are available in kit format from stock for immediate use. Many are preanalyzed, expiration dated and lot numbered, with MSDS provided. For complete details, request ChemService Catalog MXC.1.
ChemService conveniently packaged lab chemicals you can trust Box 3108, West Chester, PA 19381 Ifyour need is immediate, phone 2151692-3026 Circle No. 6 on Readers' Inquiry card
Volume 66
Number 7 July 1989
which the chemical or mixture appears on the inner surface of the material after contact with the chemical on the exterior surface of the material. Permeation rate is based on Fick's law and is a function of the diffusion coefficient of the material, the chemical concentration gradient inside and outside of the material, and the thickness of the material. Permeation rates are exmessed in terms of the amount of chemical r~~ -~~~ which pass through a given area of material per unit time (commonly, micrograms per square centimeter per minute). Breakthrough time (BT) is the elapsed time from initial contact on the outer surface of the material to the first detection of the chemical on the inside surface. Factors influencing petmeation and breakthrough are: 1. Temperature: As temperature increases, P R increases, and BT decreases. 2. Thickness: As thickness increases, P R decreases, BT increases. 3. Solubility effects of the glove material and chemical system: Even the same material manufactured by different companies may vary in chemical resistance. 4. Multicomponent liquid effects: ~~
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a. May have no experience with some of the chemical components. b. Some mixtures can permeate faster than single chemicals. e. Small amounts of rapidly permeable chemicals can carry other chemicals in with them faster. 5. Persistent permeation: Chemicals continue to diffuse into the glove material to the inner surface, even after they have been removed from the outside surface.
Proper glove selection is not an easy task. Glove permeability data are not available for many chemicals, especially for mixtures. This is oarticularlv true for research ehemicals, which may not bc in widespr~adw e in industry. National Safety Cwmcil Data Sheet 1-735-87otferp, some gurdanrr. Ilprutection is sought from one chemical, review the manufacturer's glove performance data, and choose the glove with the longest breakthrough time. If permeability data are not available and there is compelling evidence of high systemic toxicity, skin absorption, sensitization or other serious effects. esnerimental ewlunt~ona h d d be uudertaken (that is, havegluw mater~alstested irnr your application)
Mixtures are harder to evaluate. If permeability data exist for some of the eamponents of the mixtures and it is not a systemic poison, skin ahsorption problems, sensitizers, corrosives, ete., choose the gloves based on the components in highest concentration for which data are available. If some of the camoonents have some of the characteristlrs ilstpd R ~ O Wand data are not avallli>le, have the glwes t ~ r t e dfor the dppl:catim If there ls no permdnliry data, but rht mixture does not have any of the above characteristics, you can use two gloves of different compositions simultaneously or use a single glove and dispose of them within 15 min. Computer programs are also becoming available (Instant Reference Sources, see below) that store glove data and help in the selection and location process. In addition to permeability data, other factors will also need to he considered when choosing chemical protective gloves. Some additional factors to be considered are:
1. Is chemicalresistance the only requirement or is protection needed for hiological organisms, radioisotopes, and physical stress (heat, cold, cuts, vibration, ete.)?
2. How durable are the gloves? Will they be used again, or are they disposable? 3. What are our dexterity and tactile sensitivity needs? Will we have to do finefinger manipulations? Would loose gloves be a hazard? 4. What are the friction requirements? Are l h r gloves slippery? Would dropping romrthing have disnntmus conse-
quences? 5. How lone are the doves to be worn-all " dny,an huur.2 minlfivt times per dab.'' IP this a one-trme use or wmpthing we will work with daily? ~
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6. What is the cost of the gloves? Disposable vs. re-use issues are important, not only because of safety, but also because of cost.
After finally considering all the factors, you will be able to make a more informed drciviun about the glwer tu use. Later, neoprene, nitrile. poly\.myl alcohol, polpiny1 chloridr.*tr .all have their uwncharactrrirtic advantages a n d diradrantagas. Once y m h a w choscu the righl gloves fur your applimrion, i r u,ill also be important to use them properly. When using chemical-protective gloves, a few simple rules will help prevent skin exposure and minimize area&tamination: I . Avoid contact with chemicals as much as possible. Work carefully! Before
d o n n i n ~ t h r g l o v r ~ , c h r rthem k fur rips
and tears.
2. Keep gloves as clean as possible. Wash them off every 30 min when in use and always after extensive contamination. 3. There is a lot of controversy over reusing chemi-l-~rotective clothing. Do not re-use disposable gloves. I t is usually a good idea not to re-use gloves soiled with skin-absorbable, systemic poisons, corrosives, sensitizers, or 0ther very hazardous materials. If gloves are grossly contaminated with very hazardous materials, change them immediately. If gloves are to be re-used for less hazardous materials, wash in and water, and dry them daily (unless gloves are water soluble; e.g., PVA).
4. Do not wash gloves with solvents. 5. Have appropriate disposal containers
available for used gloves, and wash materials off before disposal (cheek local waste disposal regulations).
6. Make sure gloves go far enough up the arm to protect against hazards to forearms. 7. Do not wear gloves outside the designated work area (down the hall, to answer the phone, etc.).
8. Train all employees in proper glove selection and use. If in doubt, assistance should be sought
from your environmental health and safety staff, industrial hygienists, glove manufact s, or NIOSH.
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General References ~~.,i,.. conference o f ~ o v e r n m s n t a ~Indu%trial ~
~
is* (ACGIH). Cuidsiiner lor thoSaleetion olchemicol ~ o t e c ~ Ciathing;1987. Y e American Industrial Hygiene Assxiation (AIHA). Chemi-
~
i
cdPr0lccti"e Clothing Manogmph; IS&?. ~ a t i m dsafetycouncil ( ~ ~ ~ ) . u~a e ~ ~ ~i d e~- i ~ ~ t lines for Chemically Impervious Gloves',. Data Sheet I735~87;Solely & H d f h 1988. June. Nelmson, G. 0.et al. '"Glove Permeation by Olganic Chemi,I,,.A~. I , ~ Wnygipna A ~J. I984,42,217. ~ ~ ~ .
Ssnsone,E.B.;Ter~i,Y.B."ThePemeahilifyofLaho~a+AnGloves to Selected Sdv1119". Am. Indust. Hygiene A s m e 5. 1978.39.16'3. Instant Reference Sources, Inc., 7605 Roekpoint Dr., Auat i , TX,78731, (512) 345.~~67. .'chemical
clothing ~erformmceindex" by ~ ~ i .rorsberg t~, 6th "GlovES +"and "Bstanlchemid Protective Clothing Selection". (~orinformationa~purp-~n~y,nowarra~ty implied.)
