3.1 INTRODUCTION
Risks to health and safety may occur whenever there is exposure to chemical, physical or biological hazards. The degree of risk depends on the severity of the hazard and the degree of exposure. The many and varied jobs undertaken by employees and contractors worldwide present a range of risks to health and safety. Control to an acceptable level depends on the identification and evaluation of the hazards with reference to exposure standards.
It should be noted that the term "Personal Protective Equipment" includes both clothing and equipment, but for the purpose of this Guide it is abbreviated throughout the text as "PPE" .
3.2 OPTIONS FOR CONTROL
3.2.1 Determination of Control Needs
The most effective way of determining the level and type of control needed to provide employee protection is through a step – wise evaluation procedure.
This requires a considered judgment on:
a) The hazards in the workplace associated with specified jobs (consider normal operations, maintenance activities and foreseeable emergencies) and,
b) The risk to persons doing those jobs.
3.2.2 Hazards Identification
Identify the nature of the hazard, the chemical and / or physical agent, its characteristics, potential routes of entry or contact and the harmful effects of exposure to that hazard. Criteria to be addressed would include:
AGENT (what is the hazard?)
- Direct
o projectile , sharp or abrasive object , ( mechanical ) moving machinery
· Chemical
o irritant , carcinogen , systemic poison , sensitizer
· Physical
o noise , radiation , extreme temperatures , vibration , electrical , light
· Biological
o bacterial , parasitic , fungal
· PHYSICAL CHARACTERISTICS (what from is the hazard in.?)
o gas , vapour , mist , dust , fume , liquid , solid , temperature , pressure .
· POTENTIAL ROUTE (S) OF ENTRY OR CONTACT (how will the hazard act upon the person..?)
o Inhalation, skin contact, hearing, eyes, who or specific part of body, ingestion.
· Effect (s) OF EVENT (what type of effect does the exposure to the hazard cause.?)
o Physical injury, poisoning, asphyxiation, cancer, heat stroke, irritation, infection, loss of hearing, dermatitis, burns, abrasions, etc.
3.3 SELECTION AND USE OF PERSONAL PROTECTIVE EQUIPMENT (PPE)
The Selection of PPE takes account of risks to health based on knowledge of the hazard and assessment of the exposure.
Consideration is then required as to the degree of protection needed and the job tasks must be analyzed to determine if there are any constraints on selection of equipment. Foreseeable emergency situations must also be evaluated. Equipment must be correctly fitted and adjusted for maximum comfort. There is value in making a number of types available, thus providing individual choice and there by encouraging use.
3.3.1 TYPES OF PPE
PPE Can Be Divided Into Two Major Classes:
· Equipment providing protection from direct physical injuries caused by flying or falling objects, temperature extremes, abrasive and sharp edges, and
· Equipment providing protection from direct physical (E.g. noise. Heat) or biological hazards, the effects of which are determined by the dose received.
The specification of the PPE requirements is aimed at matching the protection to the risk.
Tables 1 and 2 give example of PPE which provide protection against direct physical hazards and dose dependent hazards respectively.
EXAMPLES OF PERSONAL PROTECTION
Table 1. Equipment Providing Protection From Direct Physical Hazards
| Nature of Threat | Body Zone to be Protected | PPE Examples |
| Flying Objects | Eyes | Spectacles / safety glasses, goggles, visor |
| Falling Objects | Head Feet | Helmets Safety shoes / boots |
| Abrasion | Hands | Gloves – leather |
| Hot Surfaces | Hands | Gloves – aluminum / glass fiber mixture, wool |
| Cold Surfaces | Hands | Gloves – cryogenic PVC, leather |
| Fire | Body, total | Gloves, helmet, fire approach suits, close – proximity suits. |
Table 2. Equipment Providing Protection against Dose Dependent Hazards
| Nature of Threat | Route to be Protected | PPE Examples |
| Toxic, corrosive or irritant gas, vapour, mist, dust or fume | Airway / Eyes | Respiratory Protective Equipment ( RPE ) , full face types only |
Toxic, corrosive or irritant liquid | Eyes / Sin | Visor / face shield Chemical goggles Chemical resistant gloves |
Noise | Ears | Ear plugs, muffs |
3.3.2 HEAD PROTECTION
The head - and more specifically the brain - is a part of the human body that is most susceptible to disabling injury from an impact. Such injuries are potentially extremely dangerous and severe results often persist over a long time.
Head protection can be divided into two types:
· Safety helmets
- Bump Caps
Safety helmets are intended to give the wearer protection against impact and penetration damage and are designed so that they will not fracture when struck nor transfer the force of the blow to the wearer's skull immediately below the point of impact. Helmets should be designed for comfort in use and should be of an approved type (British Standard or equivalent) to ensure they meet the required performance.
Bump caps are unsuitable for providing impact protection. They provide protection only against minor bumps and abrasions which makes them acceptable for only a few specific jobs. They are not recommended for normal use in operations.
3.3.3 FOOT PROTECTION
All boots and shoes afford some protection to the feet but are not necessarily protective footwear in the safety sense. Protective footwear must protect against hazards ranging from dermatitis to crushing injuries. Within this broad range of hazards attention must be given, for example, to the possibility of contact with chemicals, extremes of cold and heat, slippery surfaces, punctures from nails and other sharp objects, and electrical hazards (live and static).
3.3.4 EYE AND FACE PROTECTION
Equipment for the protection of the eyes and face can be divided into four groups:
(I) Spectacles
(II) Goggles
(III) Visors/face shields
(IV) Hoods.
This equipment is designed to protect the wearer from chemical and physical hazards such as chemical splashes, gases, vapours, foreign bodies and electromagnetic radiation in or near the visible spectrum (i.e. ultra-violet, infra-red light and microwave).
These hazards can cause damage in three main areas of the eye:
(I) On the surface (cornea and conjunctiva)
ii) Within the lens, and
iii) At the retina
Damage to the eye may result in permanent scarring of the surface of the eye (the cornea). Surface damage can also be caused by ultra-violet (welding "arc eye"), infra-red light, and from high power levels of microwave radiation. For maximum protection against eye injury, it is recommended that a mandatory program requiring the wearing of eye protection 100% of the time in hazardous areas, such as process areas, laboratories and workshops, is implemented.
3.3.4.1 CONTACT LENSES
Contact lenses are not PPE and in fact other special precautions may be necessary when they are used. The lenses may be lost during emergency irrigation of the eye or damaged by chemical contact. Accidental displacement can also cause temporary loss of vision.
3.3.4.2 SELECTION OF EYE PROTECTION EQUIPMENT
Eye protection is based upon the creation of a physical barrier to harmful agents. Consideration should also be given to the use of suitable shields, screens or by restricting access to hazard areas, to provide protection for bystanders and passers by no single type of eye protection will be satisfactory for all situations and circumstances. The following simple check list is suggested to assess the actual requirements.
a) Type Of Risk
· hot or corrosive liquids, chemicals - gases and aerosols
· radiation
· impact
· flying particles
· hot metals
b) Conditions of use
· temperature
· humidity
· wind velocity
· cramped work area - degree of movement - clean or dirty service
c) Types Of Use
· continuous
· intermittent
· other protective equipment
d) Required Field Of Vision
· wide
· narrow
3.3.4.3 LENSES
Lenses are available with varying degrees of impact resistance. Where there is an identified risk of eye injury from impact with a foreign object, the standardization on lenses with the higher impact resistance rating is to be recommended to avoid confusion.
Plastic lenses/shields, although more readily scratched, combine strength with moderate cost. They are considered superior to glass for resistance to impact, penetration and fogging. Special surface treatments are available to reduce scratching and fogging. Heat treated glass lenses should not be used in areas where impact hazards are high.
Eye and face protection equipment should be issued for the wearer's individual use.
3.3.4.4 GOGGLES
Flexible wrap-around one-piece safety goggles are suitable for a wide range of applications and can be worn over corrective spectacles. The basic type with mesh or perforated ventilation sides is suitable for general hazards, but for chemical liquid and vapour hazards the shielded or baffled type, preferably with anti-fogging coating, should be used. Where there is a significant risk of splashing, a visor is recommended in order to provide full face protection.
3.3.4.5 SPECTACLES/GLASSES
Safety spectacles (or safety glasses) have gained wide acceptance in industry. Although they do not provide complete protection, they do afford useful protection against a number of hazards, particularly flying particles. For the most effective protection the safety spectacles should be provided with side shields. To ensure comfort and user acceptability spectacle frames should be tight, strong and properly adjusted to the wearer. They should fit so that the eyes look through the centre of the lenses and be as close to the eyes as possible (for the widest possible field of vision) without contacting the eyelashes. The nose bridge should fit comfortably. Ideally the side pieces or temple bars should contact the head along the entire length. The bar should hook behind the ear close to the head, contacting the ear over the full length of the hook (spreading the load).
Wearers of correctly fitted spectacles who, after a trial period, still complain of headaches and that the spectacles "hurt" should be referred to the Medical Officer or an Optician for an eye test.
For people with sight defects, safety glasses with prescription lenses can be obtained.
3.3.4.6 VISORS/FACE SHIELDS,
Visors fitted to head harnesses or safety helmets are widely used, particularly in chemical process areas. The lift-up hinged type is preferred for intermittent use. The possibility of face splashes under the visor should be considered. Although such occurrences are rare, goggles plus face shield or moulded face shield may be needed for chemicals very hazardous to the eye. Where exposure to irritant vapours may occur, gas/ vapour tight goggles should be worn. Visors are resistant to fogging and can be worn together with corrective spectacle lenses.
3.3.4.7 HOODS
Hoods are less generally used except with full protective suits or as part of respiratory protective equipment. Fire approach suit hoods are normally fitted with infra-red filters having a reflective metallic coating to reduce the radiant heat load. Full face-piece masks of respiratory protective equipment, also provide eye and face protection.
3.3.5 HAND PROTECTION
Gloves are used to protect the hands against chemical, physical and biological hazards. There is no one glove that suits every purpose. Conditions, processes and materials vary so much that a given situation may require its own individual type of hand protection. The permeability and chemical resistance of the gloves to the materials handled must always be considered. The necessary information on chemical resistance and permeation is available from the chemical supplier or the glove manufacturer. Where tests show that penetration through a glove occurs, it may still be possible to recommend its use by also specifying procedures which include a maximum cumulative time period for wear. This may best be controlled by a formal system of regular glove checking, cleaning and replacement. It should be noted that most gloves are not meant to provide protection during immersion in chemicals. Although it can be practical to decontaminate and re-use gloves in certain situations, it should be noted that the cleaning process usually does not remove all the toxic material, thus reducing breakthrough time for subsequent use. Discarded and contaminated gloves should be destroyed, in order to prevent unauthorized retrieval and use. This is especially important for gloves that may have been in contact with very toxic substances.
3.3.5.1 SELECTION
Gloves consisting of a fabric support coated with a chemical-resistant substance, such as PVC, have better resistance to tearing, cutting .or puncturing than those made from the coating material alone. The fabric fibers, however, may act as wicks and considerably increase the permeability, particularly if the coating is light or has been abraded in service. Unsupported gloves have better flexibility/sensitivity but lower tear, stretch and heat resistance. Temperature seriously affects the performance of some types of glove. Thermoplastic coatings such as PVC are particularly affected and may be unusable in cold conditions either from loss of flexibility or from cracking. Solvents may affect the rate of penetration of other substances, occasionally decreasing, but more frequently increasing it; for example, aromatic solvents may increase the rate of penetration through some gloves" Higher temperatures may reduce glove performance with regard to abrasion, tear and puncture resistance and may result in increased permeability. Protection from extremes of temperature, both hot and cold, requires special materials. Specially treated leather (thermo leather) has fairly good heat resistance and has been found suitable for welding, cutting and burning applications. Synthetic fiber fabrics such as high temperature nylon (Nomex), "Kevlar", flameproof rayon and aluminized wool, can be used for high radiant heat applications. Aluminized glass fiber with insulated lining will protect against conductive heat as well as radiant heat at higher temperatures, but with poor handling sensitivity. Impervious gloves are necessary for the handling of cryogenic liquids and the vinyl coated cotton glove, foam-backed with fleecy lining, gives reasonable service although the vinyl coating tends to stiffen at the very low temperatures involved. For small or delicate work requiring manual dexterity and tactile sensitivity the thinnest possible glove consistent with adequate protection should be selected.
Fabric or leather gloves used for physical protection will increase the exposure hazard if they become contaminated with any chemicals being handled due to' prolonged contact of the contaminated material with the skin. Gloves should be provided in a variety of sizes. Also, gauntlets are usually recommended for protection against liquids. In some cases of very toxic materials it may be necessary to seal the open end of the glove to the wrist to prevent intrusion of the toxic material.
3.3.6 BODY PROTECTION
This section deals with what is usually called protective clothing and includes protection of the various parts of or the whole body as required.
The Elements Of An Effective Body Protection Program Include:
· estimation of likelihood of skin exposure
· consequences of direct skin contact
· estimation of level of protection from available clothing
· appropriate selection and documentation of basis for selection
· training employees in proper use
· cleaning and maintenance of protective clothing/equipment
3.3.6.1 GENERAL WORK CLOTHING
Work Clothes:
Some protective clothing offers no more direct body protection than ordinary street dress. In some cases special protective clothing may be provided to protect street clothes. Fabric uniforms or overalls are often supplied to protect against dirt, grease and oils. Effective laundering of re-usable work clothing is an important aspect of exposure reduction.
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