Ali Sadeddin addresses the challenges faced when selecting and procuring chemical resistant workwear.
Chemical protective workwear encompasses all forms of wearable personal protective equipment (PPE) used to guard workers against the harmful effects of chemical exposure. When handling chemicals it is necessary to protect not only the parts of your body that could come into direct contact with chemicals, but also the lungs, depending on the type of chemicals and level of hazard.
Types of exposure
A lot of chemicals recognised as dangerous to health can be easily absorbed into the human body, with the respiratory tract a major route of entry for chemicals. Exposure can be controlled through work practices such as keeping containers closed when not in use, and using fume hoods and respirators.
A further regular source of chemical exposure is eye contact. Appropriate safety eyewear must be used in any situation that holds the risk of chemicals coming into contact with the eyes. While numerous forms of eye protection are available, safety goggles specifically designed to protect from chemical exposure are the only appropriate eyewear when handling dangerous liquid chemicals.
Chemicals can also affect the body through the skin. Generally speaking, skin absorption is considered a major cause of the total body exposure to hazardous chemicals. Healthy skin is an effective barrier to many chemicals, but any small cuts or abrasions can allow direct entry into the body. The skin can also be the target organ in the development of diseases such as dermatitis. Skin diseases can also increase the chance of absorption.
Selecting chemical protection is no easy task. It can include gloves, aprons, lab coats, and full body clothing, all of which can be manufactured from a range of materials. It is very important to know that there is no single textile or chemical protective item that will guard the user from all forms of chemical hazards. Manufacturers of chemical protective clothing conduct permeation and degradation tests on their garments. These data must be consulted before the appropriate protective clothing can be selected.
The Occupational Safety and Health Administration (OSHA) 29 CFR 1910.132 states: “Protective equipment including PPE for the eyes, face, head and extremities, protective clothing, respiratory devices and protective shields and barriers should be provided, used and maintained in a sanitary and reliable condition wherever it is necessary, by reason of hazards from processes, the environment, chemical hazards, radiological hazards or mechanical irritants encountered in a manner capable of causing injury or impairment in the function of any part of the body through absorption, inhalation or physical contact.”
The OSHA regulation also requires that a hazard assessment of the workplace be performed to determine the need for PPE, and that the employees receive training on the use and limitations of the selected protective equipment. Health and safety departments can conduct the hazard assessment and training.
When it comes to chemical protective clothing (CPC) there are fewer standards covering it than compared with protection against other forms of hazards. While there are no OSHA standards, there are instead guidelines pertaining to CPC. In addition, NIOSH standards cover respiratory protection. While ASTM test methods offer little guidance for CPC selection, the new ANSI standard provides help in this respect. The National Fire Protection Association’s (NFPA) standards are mainly used, as these cover the selection and use of CPC. To be on the safe side the selected CPC has to comply, at a minimum, with NFPA 1991 2005, NFPA 1992 2005, NFPA 1994 2007, and NFPA 1999 2008.
The NFPA’s Hazardous Materials Response Handbook states: “Personal protective equipment can provide the wearer with a false sense of security. The protected internal environment of a totally encapsulating suit can also induce rapid fatigue and heat stress, limit vision and impair communications. Avoiding under protection vital for hazardous material responders, but over protection can cause its own needless hardship.”
Furthermore, Section 8 of the 1999 OSHA Technical Manual TED 1-0.15A states: “In general, the higher the level of protection offered by CPC, the greater the associated risks. For any given situation, equipment and clothing should be selected that provide an adequate level of protection. Over protection as well as under protection can be hazardous and should be avoided.”
PPE must be used carefully, since there are hazards linked with its use. The most important hazard in the selection of the proper CPC is usually the user, who may have inaccurate expectations of the protective clothing.
Compliance is crucial
It is very important before purchasing any chemical protective PPE to look for test methods that focus on chemical resistance, degradation resistance, penetration resistance and permeation resistance. The tests should reflect properties for protection against identified hazards. You should also look to the overall design and features, consider human factors and provide for compatibility with other PPE that can be used in combination with chemical protection. You should seek product standards as a basis and list required performance properties in addition to acquiring data on products being considered. All relevant design features should be included to create product checklists that can help you in the selection process.
Take the selection of chemical protective gloves as an example. You should look to the performance properties including chemical (permeation) resistance, cut resistance, puncture resistance, abrasion resistance, and hand function including grip, dexterity and tactility. Furthermore, you must consider design features such as full hand protection two inches past the wrist crease, available in at least five sizes, and with a knit lining for comfort. To be sure of the above, consult compliance data and warranties for information such as product quality.
As another example, when procuring chemical protective coveralls your needs vary greatly. Workers could require protection against splashes of concentrated sulphuric acid contact for tasks of between one and two hours in duration, or they may encounter very few physical hazards. While offering this protection it is important that workers’ movements are not restricted. Workers may also need to wear eye, face, hand and foot protection.
In the previously mentioned requirements you should consider the performance properties of penetration resistance, liquid-tight integrity, sufficient durability, minimum physical hazard resistance (to puncture, cut, abrasion, tear) and minimum effect on mobility. The design features should include closure in the back of the coverall and interfaces for gloves, boots, and head and face protection. Compliance data and warranties will give you this information.
Comfort and ease of use
Since protective clothing affects mobility, vision, ease of communication and hand function, it should be comfortable, retain the health of skin and allow the escape of heat from the body. CPC that has the minimum affect on the user’s mobility, vision and hand function should be selected, as comfort and ease of use are crucial to ensure PPE protects the wearer effectively against anticipated hazards.
To achieve the desired outcome from using and wearing the right CPC, user training is a very important factor. Workers may be provided with the right PPE, but misusing it may counteract its function, making it part of the hazard. In addition to addressing users’ perceptions of hazards, training should examine the experience of working in PPE and the use of different suits with different constructions.
Published: 30th Oct 2014 in Health and Safety Middle East