SITE SAFETY
TRAINEE OBJECTIVES
After completing Section 5, you will be able to:
SITE SAFETY
Due to the nature of the work, lead abatement workers face a higher risk of accidents and injury than the typical construction worker. The personal protective equipment worn to reduce lead exposures can increase the accident potential by:
In short, lead abatement workers are subjected to many factors that may reduce their ability to react, and thereby, increase their chances of an accident.
ACCIDENTS
An accident is an undesirable, unplanned event resulting in personal physical harm, damage to property, or interruption of business. An accident may be the result of an unsafe act, such as standing up in a small boat or not wearing a respirator properly. It may also be the result of an unsafe condition, such as a leaking boat or dangerous atmosphere. These situations can be related, since an individual's unsafe act can result in an unsafe condition for someone else.
Preventing Accidents
The following are two main approaches to reducing or preventing accidents:
Eliminate Unsafe Conditions
Workers must look for conditions that can contribute to an accident, and then work to remove exposure to these conditions. Examples are enclosing live electrical circuits or providing workers with the proper protective equipment. This is the best approach, but it is difficult to eliminate all unsafe conditions. It's more difficult to predict or anticipate where such conditions may exist or develop on an lead abatement job.
Reduce Unsafe Acts
Each worker must make a conscious effort to work safely despite the hazardous conditions that may exist at any site. A high degree of safety awareness must be maintained so that the safety factors involved in a job become an actual part of the job.
GENERAL SAFETY
Safety is "the state of being secure from harm, injury, or danger." To be safe, a worker acts in two ways-offensively and defensively. When a worker acts offensively, he or she protects against controllable actions. When a worker acts defensively, he or she maintains an awareness of actions or situations that may be created by others, or by things taking place.
Regulations established by both Federal and State Occupational Safety and Health Administrations (OSHA) cover many of these hazards. Employers are required to follow these regulations on the job site, including lead abatement job sites. Safety procedures that you are familiar with from your previous work experiences deal with:
If you continue to follow the procedures that you already are familiar with, they will protect you in situations you may encounter during lead abatement work.
Safe Work Practices
Safe work practices are "those work habits one can adopt and use to protect himself/herself while performing specific duties." Many of the safe work practices used during lead abatement are designed to limit exposure to lead-containing material. The following examples of work practices would apply to most bridge, steel structure, and demolition jobs:
General Site Safety
General site safety procedures include the use of engineering controls, safe work practices, and personal protective equipment. Employing all available and possible protective measures provides a safer working environment for all workers.
ELECTRICAL SAFETY
The use of wet methods increases the chances for electrical shock when working around electrical panels, conduits, light fixtures, alarm systems, junction boxes, computers, transformers, etc.
Actions to Take
Extension Cords
LADDERS AND SCAFFOLDS
Projects involving lead removal on steel structures always present risks to workers from falls, slips, or trips. Scaffolding and ladders are almost always needed to do the job.
Ladders
The following maintenance and use rules should be adhered to:
Scaffolding
Most bridge, structural steel, and demolition projects involve the use of scaffolding. Proper set-up, regular inspection, and basic maintenance is important. In many removal projects, mobile scaffolding provides a convenient and efficient work platform. OSHA standards require that when freestanding mobile scaffolding is used, the height shall not exceed four times the minimum base dimension. This requirement is based on the fact that scaffolding is easily tipped over. Since relatively little force is required to tip a scaffold, it becomes important to make sure that wheels on mobile scaffolds turn freely and are lubricated. All components, such as cross bracing, railings, pin connectors, planking or scaffold grade lumber, should be available before the units are assembled.
When workers will be riding mobile scaffolding, the base dimension should be at least one-half the height. Be careful to keep debris bagged and obstacles off the floor where mobile scaffolds will be used. If a wheel catches on debris on the floor when the unit is moved, additional force will be required to move it. This additional force may tip the unit over. OSHA requires that employers not allow employees to ride on rolling (manually propelled) scaffolding unless the following conditions exist:
Slips, Trips, and Falls
Guard rails and toe boards should always be installed on scaffolding used for abatement projects. Workers are usually looking up while working, and can easily step off the edge of scaffold without rails or toe boards.
Areas sealed with poly and kept damp to reduce airborne fibers become very slick. Disposable booties are a potential trip hazard. Air and electrical lines create trip hazards. All of these conditions create potential worker hazards, even before removal begins. When lead and other debris are removed, the accumulations should be bagged and removed from the floor as soon as possible. This simple step, which may require more initial effort, will make cleanup easier and the overall job far safer.
Summary
HEAT STRESS
Heat can be a serious hazard on the lead abatement job, especially in crawl spaces and boiler rooms. If workers will be exposed to excessively hot environments, an extensive program specifying safety work practices should be established prior to starting the work. In general, the hotter and more strenuous the job, the greater the chance of heat stress. The severity of heat stress depends on many factors, including:
Under normal conditions, the body produces more heat than necessary to maintain the body temperature. Air currents and evaporation of sweat can remove heat when the temperature and humidity of the surrounding air is lower than the body temperature. However, when the air temperature is above body temperature and the humidity is high, the body may not be able to get rid of extra heat fast enough. If the body can't give off heat fast enough, the body temperature will rise.
Workers Who are at Risk
Forms of Heat Stress
There are four forms of heat stress that result from exposure to high temperature. Generally, productivity also decreases significantly with increased heat.
Heat Rash
Heat rash is the mildest form of heat stress. This is how the body reacts to hot and humid environment. It is caused by heavy sweating where sweat is not easily removed by skin evaporation. Common signs and symptoms include reddening of the skin and development of blisters or a rash.
Heat Cramps
These are probably due to a low sodium chloride level in the blood. The worker experiences severe, painful muscular contractions of the arms, legs, hands, and trunk. Cramps are always preceded by marked sweating. Body temperature may be above or below normal with a rapid pulse. Cramps are usually in the extremities, and generally, follow heavy exertion, but may also take place hours later. If heat cramps occur, the worker should rest in a cool place, and increase fluid intake. (See "Preventive Measures.")
Heat Exhaustion
This is the result of not getting enough water. The individual becomes pale, has cold, clammy skin, and is weak to the point of exhaustion. He/she may also have a headache, vomiting, nausea, muscle cramps, diarrhea, and giddiness. The blood pressure is low, and the temperature may be above or below normal. The condition resembles surgical shock. It may be preceded or followed by heat cramps. There is no increase in body core temperature. If heat exhaustion occurs, the worker should rest in a cool area and drink plenty of water (i.e., 1 pint). (Refer to the topic heading, "Preventive Measures" in this section.)
Heat Stroke
Heat stroke is the most serious heat disorder and results from exposure to excessive heat. The skin becomes hot and dry (or red and mottled), and there is a rapidly rising body temperature with a rapid pulse and deep breathing. Blood pressure is high, and there may be unconsciousness, convulsions, or deep coma. The onset may be gradual, with mental excitement and dryness of mouth and skin, or may be sudden with delirium, stupor, or coma. This condition has a death rate of 30% to 50%. If a worker experiences the symptoms of heat stroke, he or she should seek medical attention immediately.
Table 5-1 summarizes the four forms of heat stress and their signs and symptoms.
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Preventive Measures
Avoid entering hot areas whenever possible.
Monitoring for Heat Stress
Treatment/Emergency Measures
CONFINED SPACE ENTRY
A confined space is an area that has any one or all of the following characteristics:
Improper entry into confined spaces results in a significant number of industrial and construction accidents, including fatalities, every year.
Typical examples of confined spaces include storage tanks, tank trucks, process vessels, boilers, pipelines, pits, septic tanks, vats, manholes, utility vaults, ventilation ducts, silos, sewers, and trenches.
Confined Spaces Hazards
The primary hazards that may be found in confined spaces are:
Hazardous Atmospheres
Since, in most confined spaces there is a lack of natural air movement, the most common hazard is hazardous atmospheres. There are three types of hazardous atmospheres that workers should recognize:
Oxygen-deficient Atmospheres
An oxygen-deficient atmosphere has less than 19.5% available oxygen. Any atmosphere with less than 19.5% oxygen should not be entered without an approved self-contained breathing apparatus (SCBA) or airline respirator with escape. Even if testing shows oxygen levels above 19.5%, remember there is normally a lack of ventilation or natural air movement in a confined space. Any work that uses up oxygen, such as welding, cutting, or brazing, may cause the oxygen level of the confined space to fall below 19.5%. It is important, therefore, to periodically test the air in the confined space for oxygen content when work is being performed without an appropriate SCBA, airline respirator, or ventilation.
Flammable Atmospheres
A flammable atmosphere develops when a flammable gas, vapor, or dust is present in the air at concentrations between the Lower Flammable Limit (LFL) and the Upper Flammable Limit (UFL). If a source of ignition (e.g., a sparking electrical tool) is introduced into a confined space containing a flammable atmosphere, an explosion will result.
Toxic Atmosphere
Most substances (liquids, vapors, gases, mists, solid materials, and dusts) should be considered hazardous in a confined space. The following are some sources of toxic substances that may be present in confined spaces:
In view of these extremely hazardous atmospheres that can exist in confined spaces, the following rules should always be followed:
Reducing the Danger
The following procedures will reduce the dangers associated with confined spaces:
Isolation
Isolation of a confined space eliminates the hazards associated from moving or driven equipment, and the unexpected entry of process liquids, steam, or water.
Isolation is the process whereby the space is removed from service by:
Testing the Atmosphere
It is important to understand that some gases or vapors are heavier than air and will settle to the bottom of a confined space. Also, some gases are lighter than air and will be found around the top of the confined space. Therefore, it is necessary to test all areas (i.e., top, middle, bottom) of a confined space with properly calibrated testing instruments to determine what gases are present. If testing reveals oxygen deficiency, or the presence of toxic gases or vapors, the space must be ventilated and retested before workers enter. If ventilation is not possible and entry is necessary (e.g., for emergency rescue), workers must have appropriate respiratory protection.
Ventilation
Ventilation by a blower or fan may be necessary to remove harmful gases and vapors from a confined space. There are several methods for ventilating a confined space. The method and equipment chosen are dependent upon the size of the confined space openings, the hazards gases to be exhausted, and the source of makeup air.
Under conditions where flammable gases or vapors have displaced the oxygen, but are too rich to burn, forced air ventilation may dilute them until they are within the explosive range. Also, if inert gases (e.g. carbon dioxide, nitrogen, argon) are used in the confined space, they may have displaced the oxygen content. Therefore, the space should be well ventilated and retested before a worker may enter.
A common method of ventilation requires a large hose with one end attached to a blower and the other lowered into the confined space. For example, a manhole would have the ventilating hose run to the bottom to blow out all harmful gases and vapors. The air intake would be placed in an area that will only draw in fresh air. Ventilation should be continuous, where possible, because in many confined spaces, the hazardous atmosphere will form again when the flow of air stops.
Standby and Rescue
A standby person should remain on the outside of the confined space and be in constant contact (visual or speech) with the workers inside. The standby person should not have duties other than to serve as standby and know whom to notify in case of emergency. Standby personnel should not enter a confined space until help arrives, and then only with proper equipment.
More than 50% of the workers who die in confined spaces are attempting to rescue other workers. Rescuers must be trained in, and follow, established emergency procedures and use appropriate equipment and techniques (e.g., lifelines, respiratory protection, standby persons). Steps for safe rescue should be included in all confined space entry procedures. Rescue should be well planned and drills frequently conducted on emergency procedures. Unplanned rescue, such as when someone instinctively rushes in to help a downed co-worker, can easily result in multiple fatalities.
Confined Space Entry Procedure
Basic elements of any comprehensive confined space entry procedure include:
Authorization and Permit
No person should enter a confined space, unless a confined entry permit has been prepared and authorized by the appropriate individual (normally, a supervisor).
Pre-entry Precautions
Ensure that the confined space has been isolated to prevent entry of hazardous materials. Locking and tagging, removal of spool pieces, and installation of blanks are acceptable methods. Lock out and tag out all associated electrical and mechanical equipment.
Pre-entry Testing
Confined spaces shall be tested for hazardous atmospheres, including, as a minimum, flammable vapors (percentage of LEL), oxygen deficiency (percentage of oxygen) and toxic materials (concentration of any unknown contaminant). Result of testing (instrument readings) should be noted on entry permit.
Entry Decision
No one may enter a confined space until all items on the confined space entry permit are completed and signed. Appropriate authorization signatures must be in place.
Standby Observer
Personnel working in a confined space must be under the constant observation of a standby observer who is outside the confined space. The standby person should review the checklist before permitting any confined space entry.
Rescue Harness
Every person entering a confined space must wear a rescue harness or wristlets with a lifeline attached. The end of the lifeline must be secured outside the confined space.
Dangerous Atmosphere
Where an oxygen deficiency or a potential fire hazard exists, or could develop, all persons within the confined space must wear SCBA.
Emergency Actions
In the event of an emergency, the standby person must:
FIRE SAFETY
A few fire safety concerns are exits, travel distances, emergency lighting, and alarm systems.
Some protective clothing will burn and melt quickly. It can shrink, adhere to skin, and rip as it burns. Heavy black smoke is a combustion byproduct. Polyethylene and other fabric type containments are combustible. They start burning slowly and pick up speed as more heat is generated, giving off heavy smoke as the fire progresses. Flame spread is slow and steady. Sheeting should be kept away from heat sources, such as transformers, steam pipes, and boilers that will be heated during removal. (Polyethylene should not be allowed to come in contact with surfaces above 150ºF.)
Avoiding Fire Problems in Control Areas:
Effective December 11, 1980, OSHA revised its fire safety standards. OSHA now requires a written emergency action plan and fire prevention plan. Briefly, the essential elements of the plans include:
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ASSIGNMENT SHEET
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