Canadian Occupational Safety

APRIL/MAY 2017 23 into an oven to pull out a hot metal rack or who is cleaning with extremely hot water and chemicals." When other hazards are present, it may not be possible to select the glove material based on chem- ical protection alone. Alternatively, the worker may have to wear one kind of glove on top of another. If the hazard is both corrosive and toxic, give prior- ity to protecting against toxicity. While a chemical burn can be treated, the injury cannot be treated once the chemical has been absorbed through the skin into the body. Finally, make sure the gloves fi t properly. Gloves that are too big or small may cause problems. They should be long enough to cover all potentially exposed skin on the wrist and forearm. Once you have done the job analysis and identi- fi ed the chemicals, locate each chemical's chemical abstracts service (CAS) number and safety data sheet (SDS). The SDSs will indicate the potential health effects of each chemical and the type of glove best suited to it. For more information, a safety manager can refer to the National Institute for Occupational Safety and Health (NIOSH)'s Recommendation for Chemical Protective Clothing database, says Bruce MacKinnon, an instructor in the occupational health and safety certifi cate program at the University of Western Ontario in London. The chart allows the user to search by chemical and indicates which materials are recommended based on the length of time it takes the chemical to penetrate the material. Indi- vidual manufacturers and distributors also publish such glove selection guides. These charts provide chemical resistance data of various materials that have been tested based on ASTM test standards. Materials are rated on two characteristics: permeation and degradation. Permeation refers to the penetration of the glove by the chemical. For each material tested, there is a "penetration rate" — the rate at which the chemical passes through the material and a "breakthrough" time — the length of time it takes for the chemical to go completely through the glove. Degradation measures the deterioration of the physical properties of the glove, for example, softening or hardening, resulting from contact with the chemical. Charts will usually also provide information on how suited the glove is for the chemical, in a rating ranging from "excellent" to "not used" or "not recommended." "If you wear Latex and you're working with acetone, for example, they will tell you the rate of penetration is about 30 seconds," MacKinnon says. "Within about 30 seconds of getting acetone on the Latex gloves, you will see them start to expand like a balloon. Within another 30 seconds, the gloves will start to fall apart. Now you've reached degrada- tion, where there's a full breach of the PPE." Many materials are used in the manufacture of chemical resistant gloves, including butyl, neo- prene, nitrile, linear low-density polyethylene (LLDPE), natural rubber, neoprene mix, polyvi- nyl alcohol and polyvinyl chloride (PVC). Wool, leather and cotton, however, should never be used for chemical handling. They're very permeable and will soak in anything that spills on them, so chemi- cals are easily transferred to the skin, says Terry Thomas, Occupational Safety Standard of Excel- lence (OSSE) technical advisor at the Chilliwack, B.C.-based Manufacturing Safety Alliance of BC. It is important to always consult your glove man- ufacturer or distributor. Different manufacturers make gloves differently — using materials in differ- ent quantities and thicknesses, for example, which affects permeation rates — and they can provide specifi c information about the gloves they sell. EMPLOYER'S RESPONSIBILITY Provincial regulations generally state it is the duty of the employer to determine the protection required and make sure workers wear appropriate PPE. It is necessary for the employer to have a safety professional or other competent person conduct the risk assessment and select the most suitable gloves. "There are so many types of gloves out there to meet different types of things — you can have nitrile gloves that are very specifi c to chemical han- dling, specifi c to biological handling or specifi c to handling delicate electronic components," MacKin- non says. "It's important that the person doing the risk assessment understand what are the risks and what do they need to do to mitigate those risks. So the burden is on the employer." Whether provincial legislation specifi cally requires the employer to pay for the gloves varies among jurisdictions. In Alberta, for example, OHS law does not say who pays for safety gloves, while in British Columbia and Quebec, employers are required to pay for chemical resistant gloves, Thomas says. In the case of an extremely hazardous chemical, provincial OHS regulators expect the employer to try to engineer in a delivery or handling system to minimize the actual worker exposure to the chemical, Thomas adds. For example, instead of pouring hydro- chloric acid out of a large container into a working container, you might be able to use a delivery system. Some systems have a pump attached to the container that allows the product to be decanted into a smaller container — or through a series of hoses — and delivered right into the work in progress. Chemical resistant gloves should come with the manufacturer's instructions on how to properly decontaminate or clean and maintain them, says Chouljian. "You should clean the gloves as the sup- plier or manufacturer recommends, so you're not causing the material to be degraded or eroded, which causes the glove to not work as it's supposed to." Workers should be aware of the chemi- cals they are using and what their risks are. They should also know to inspect gloves for damage before putting them on. Damaged gloves should be discarded. "Any tears or cuts in the gloves could cause the hazardous chemical to leak through, which renders the gloves useless because the hands are being exposed to the hazard. Before putting on the glove, double check to make sure it is in good condition and they've been maintained properly," she says. Because the selection of gloves is chemi- cal specifi c, a company that uses a number of chemicals may need several different kinds of gloves for workers, Thomas says. This is why employers should do an inventory of all the chemicals they have in their workplace and try to reduce or standardize the chemicals they use. "I've been in workplaces where they have more than 400 different, controlled products from vari- ous manufacturers. But if they start standardizing the type of paint they use, the type of solvent they use for cleaning metals, they can reduce their chem- ical inventory by 75 or 80 per cent," he says. "If you can standardize your chemicals, you can also reduce the various types of PPE that you require, especially when it comes to gloves." After sustaining the burn, the laboratory worker who was burned by the trifl uoroacetic acid said she was not aware that handling that type of chemical could produce such a burn. In fact, trifl uoroacetic acid can form hydrofl uoric acid when it comes in contact with moisture. Moreover, hydrofl uoric acid can cause deep burns that may not become painful for several hours after the worker comes in contact with the chemical. The lab made several mistakes. First, it should have kept a hydrofl uoric acid burn kit nearby, says the American Industrial Hygiene Association (AIHA). It should also have assumed containers are con- taminated and made sure workers wore appropriate gloves when handling chemical containers. Finally, it should have made sure workers were aware of the hazards of the chemicals before handling them. Linda Johnson is a freelance journalist based in Toronto. She can be reached at lindajohnson@sympatico.ca. GLOVE CARE It's important to take good care of all types of safety gloves, but there are certain considerations when caring for gloves in chemical environments. • Before putting on gloves, wash and dry your hands carefully. • In the event of prolonged use, do not use gloves beyond the recommended exposure time. • Regularly check that the gloves have not become porous or are displaying any signs of degradation. • Where appropriate, folding the sleeve of the glove over slightly can help prevent substances coming into contact with arms. • Before removing gloves, follow the advice on the user instructions. • When removing the second glove, do not touch the outside with the bare hand, but grip it by the inside of the sleeve. • Before reusing gloves, check that they are dry, inside and out. Source: Showa

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