Basic Safety

Whenever you work in a hazardous environment, such as a construction site, lab, or production facility, you must always be aware of the potential dangers you face. Your workplace is required by law to provide you with equipment and facilities that meet standards set by OSHA, but you will have to be an active participant in your own safety.

You can use three lines of defense to help you get through the day safely: engineering controls, personal protective equipment (PPE), and good work habits.

Personal Protective Equipment (PPE)

Personal protective equipment (PPE) consists of anything that you would wear to protect yourself from materials or situations. It can include protective gloves and eyewear for cutting and grinding operations, respirators for working with chemicals that put out harmful vapors, and specialized goggles for working with lasers.

Your PPE protects you not only from short-term accidents, such as cuts or flying shards of glass, but also from damage that can build up over time. Such damage may include dust from construction operations such as drywall sanding that can build up over time in your lungs and cause diseases such as silicosis, or exposure to chemicals such as solvents that can have harmful long-term or chronic effects as well as harmful short-term effects.

Whenever you use PPE, inspect it carefully to ensure that it is in good condition. Look for cuts, tears, or other signs of damage in protective outerwear such as gloves or aprons. Inspect eyewear for cracks or pitting. If you use goggles designed to protect you from certain light wavelengths, make sure they are clean and free from scratches that could reduce their effectiveness.

If you wear contact lenses, be sure your facility allows them in your work area. If you work with adhesives or solvents, you should avoid wearing them anyway, because splashed chemicals could be trapped by the lens and be more difficult to wash out. You may be able to obtain safety goggles with prescription lenses if you have to use them on a regular basis.

If you work with a respirator, test it every time you put it on. Cover the canisters with your hands and try to inhale, then cover the exhaust port and try to exhale. The respirator should form a good seal with your face, and no air should leak through the canisters or exhaust.

Some construction areas may require hardhats. Do not take these warnings lightly. Even a small hand tool dropped from a few feet can injure or kill you if you are not protected. Hardhats are designed to absorb the shock from falling objects so your head doesn't have to. To make sure the hardhat fits properly, adjust the inner band so that it fits snugly against your forehead and does not allow the hat to move around on your head. Make sure there is enough room between the suspension and the hardhat shell to absorb any blows.

Good Work Habits

Good work habits are in some ways the simplest and most effective means to working safely. Good work habits can help you prevent accidents and spot potential problems in time to correct them.

Here are some general rules for working safely:

• Keep a clean workspace. Clean up at the end of your work day and store tools properly. A “rat's nest” can hide problems and add to confusion.
• Observe your surroundings. Look up from what you are doing once in a while to make sure everything around you is the way it should be.
• Use tools for the job they were designed to perform. Misuse of tools is one of the most common causes of accidents in the workplace.
• Do not eat or drink in the work area. In addition to accidentally drinking from the wrong bottle, you could accidentally ingest glass fiber or other dangerous materials that might get mixed in with your food.
• Report problems or injuries immediately. Let your facility supervisors know about hazards so they can correct them as soon as possible.
• Know how to reach emergency personnel. Have emergency numbers posted by the nearest telephone so you don't waste time fumbling through a directory in an emergency.
• Put your emergency contact information in your cell phone.

Let's look at some of the hazards directly related to your work with fiber optics.

Federal Regulations and International Standards

Federal regulations and international standards have been created to prevent injuries from laser radiation.

In Chapter 4, “Optical Fiber Construction and Theory,” TIA and ITU were introduced as organizations that publish standards on the performance of optical fibers used in the telecommunications industry. There is a difference between a standard and a federal regulation. A federal regulation is a law. If there are federal regulations for a specific type of product sold in the United States, such as a laser, that product must meet federal regulations. However, it does not need to meet any standards. A standard only provides guidance; it is not a law.

Federal Regulations

The U.S. Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) is responsible for eliminating unnecessary human exposure to man-made radiation from medical, occupational, and consumer products. The FDA has had performance standards for light-emitting products since 1976. These performance standards are described in the Code of Federal Regulations 21 CFR, Subchapter J.

Fiber-optic equipment sold in the United States that contains a laser must meet 21 CFR, Subchapter J. However, it is not required by 21 CFR, Subchapter J to meet any standard. Many fiber-optic products that contain lasers only meet 21 CFR, Subchapter J.

21 CFR, Subchapter J encompasses all consumer products that contain a laser. In this chapter, only the areas of 21 CFR, Subchapter J typically required for fiber-optic communication and test equipment will be addressed; detailed information can be obtained from the FDA website:
www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?FR=1040.10

The laser classifications described in 21 CFR, Subchapter J are based on emission duration and emission limits for specific wavelengths. There are two wavelength windows that apply to fiber-optic communication and test equipment:

1. >400nm and ≤ 1400nm
2. >1400nm and ≤ 2500nm

CFR, Subchapter J divides laser products into classes and defines the labeling requirements based on the optical output power:

• Class I products do not require a label.
• Class IIa products require a label; however, there is no logotype for this label.
• Class II products require a “Caution” label affixed bearing the warning logotype “A.”
• Class IIIa with an irradiance less than 2.5mW must have a “Caution” label affixed bearing the warning logotype “A.”
• Class IIIa with an irradiance greater than 2.5mW, Class IIIb, and Class IV laser products must have a “Danger” label affixed bearing the warning logotype “B” similar to the labels, as shown in Figure 6.1.

The classification tables for accessible emission limits for laser radiation found in 21 CFR, Subchapter J are very detailed and cover all consumer laser products. The following is a list of the hazards associated with each class. Many of the products used in fiber-optic communication systems and test equipment are Class I; however, some equipment may be Class IV.

1. Class I These levels of laser radiation are not considered to be hazardous.
2. Class IIa These levels of laser radiation are not considered to be hazardous if viewed for any period of time less than or equal to 1,000 seconds but are considered to be a chronic viewing hazard for any period of time greater than 1,000 seconds. A label is required bearing the wording “Class IIa Laser Product—Avoid Long-Term Viewing of Direct Laser Radiation.”
3. Class II These levels of laser radiation are considered to be a chronic viewing hazard. A caution label is required that states “DO NOT STARE INTO THE BEAM” and “CLASS II LASER PRODUCT.”
4. Class IIIa These levels of laser radiation are considered to be, depending on the irradiance, either an acute intrabeam viewing hazard or chronic viewing hazard, and an acute viewing hazard if viewed directly with optical instruments. A caution label is required with an irradiance less than or equal to 2.5mW. The caution label should state “LASER RADIATION—DO NOT STARE INTO THE BEAM OR VIEW DIRECTLY WITH OPTICAL INSTRUMENTS” and “CLASS IIIa LASER PRODUCT.”

   A danger label is required with an irradiance greater than 2.5mW. The danger label should state “AVOID DIRECT EYE EXPOSURE” and “CLASS IIIa LASER PRODUCT.”

5. Class IIIb These levels of laser radiation are considered to be an acute hazard to the skin and eyes from direct radiation. A danger label is required that states “LASER RADIATION—AVOID DIRECT EXPOSURE TO BEAM” and “CLASS IIIb LASER PRODUCT.”
6. Class IV These levels of laser radiation are considered to be an acute hazard to the skin and eyes from direct and scattered radiation. A danger label is required that states “LASER RADIATION—AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION” and “CLASS IV LASER PRODUCT.”

Laser Safety

Because most lasers used in fiber-optic systems emit IR radiation, you cannot see the beam, no matter how powerful it is. As a result, you will not be able to tell if the system is powered, especially if you are working with a piece of fiber far from the transmitter.

You should treat an optical fiber coupled to a laser with the same caution that you would treat electrical cables connected to a breaker panel. Do not assume that the system is turned off, especially if you have to use a microscope to look at the connector endface. Do not take anyone else's word that the system is off or that the fiber is uncoupled from the laser. You will have to endure the results for the rest of your life.

Unless you can be sure that the fiber is not coupled to a laser, do not look at the connector endface without some kind of protection. Use filters and protective eyewear that block out the specific wavelengths used by the lasers. Use a video microscope when available instead of a handheld optical microscope to view the endface of a connector.

Hazardous laser areas should be clearly identified with warning placards and signs stating that access is limited to personnel with proper safety gear and authorized access, as shown in Figure 6.1. Do not ignore these signs or think that they don't apply to you. They are there for your protection and for the safety of those working inside the restricted areas.

If the lab has a separate door and a hazardous laser is operating inside, the door should have interlocks to kill the laser before the door is opened. Some of these doors may have separate combination locks to prevent unauthorized entry.

Isopropyl Alcohol

Even though alcohol is commonly used in the home and the lab, its hazards should not be ignored or taken lightly. Alcohol vapors escape into the air easily, and they can cause damage to your liver and kidneys if they are inhaled. The vapors are also highly flammable and can ignite if exposed to a spark or flame in high enough concentrations.

Alcohol can also cause irritation to your eyes, skin, and mucous membranes (nose and mouth) if it comes in direct contact with them.

Always use alcohol in a proper dispenser, shown in Figure 6.3. Store and transfer it carefully to avoid spills and excess evaporation. If you do spill any alcohol, clean it up with a dry cloth and dispose of the cloth in a container designed for flammable waste materials. As with all flammables, do not use alcohol in areas where sparks, open flames, or other heat sources will be present.

It's important to remember that alcohol flames are almost invisible, and spills could lead to a mad scramble as you try to dodge flames you cannot see. Alcohol fires can be extinguished with water or a Class A fire extinguisher.

Solvents

Many solvents have similar properties that require that you handle them with great care. Like alcohol, solvents are very volatile and sometimes flammable. Their primary danger, however, is their hazard to your health.

One of the health hazards posed by solvents comes from the fact that they can cause excessive drying in your skin and mucous membranes, and the resultant cracking of the surface layers can leave you open to infection. The hazard is more serious if you inhale the solvent vapors, as they can damage your lungs and respiratory system.

Solvents can also cause organ damage if inhaled or ingested. The molecules that make up most solvents can take the place of oxygen in the bloodstream and find their way to the brain and other organs. As the organs are starved of oxygen, they can become permanently damaged. One of the first signs that this kind of damage is taking place is dizziness or a reaction similar to intoxication. If you feel these symptoms, get to fresh air immediately.

Solvents may come in glass or plastic containers. Make sure that the container you are using is properly marked for the solvent it contains. Do not leave solvent in an unmarked container.

If you are carrying solvent in a glass bottle, use a rubber cradle to carry the bottle. The cradle protects the bottle from breaking if it falls.

Never leave a solvent container open. Keep the top off just long enough to transfer the amount necessary for the job, and replace it firmly to prevent the vapors from escaping.

Anaerobic Epoxy

The two-part epoxy used for making connectors is typically used in small quantities and does not present any immediate health hazards. If you are working in an enclosed space, however, such as the back of a van or an access area, vapors from the adhesive portion can irritate your eyes, nose, and throat. If you feel any of these symptoms, get to an open space immediately. The adhesive can also irritate your skin or eyes on contact. If you get any of the adhesive on you, wash the area immediately. If any material splashes in your eyes, flush them for 15 minutes at an eyewash station or sink.

Use caution when working with the primer portion of these adhesives. With a flash point of –18° C, it is highly flammable. Do not use anaerobic epoxy where there is an open spark or flame or where heating components or elements are being used.

As with solvents, do not leave epoxy containers open any longer than necessary to dispense the amount you are using.

Electrical

When fiber-optic cabling runs through the same area as electrical wiring, use extreme caution with tools and ladders. One wrong move can send enough current through your body to kill you. Remember that electrical fields can exist beyond a cable's insulation if high voltages are present, so use wooden ladders to reduce the possibility of exposure to induced voltages. Use care with cutters and other tools to avoid accidental contact with electrical wires, and report any hazardous conditions that may exist.

Remember that high voltage causes most of its damage by making muscles seize up, including the heart and lungs. The greatest chance of damage comes when current passes through your heart to get the ground, such as when you touch a wire with your hand and your opposite leg provides the path to ground, or when the current passes from one hand to the other.

If you accidentally grab a live wire, the current may keep your hand clenched, making it nearly impossible to release the wire. If you see someone who is in this situation, do not try to pull them away with your hands. You may be caught up in the circuit as well. Instead, use a nonconducting stick, such as a wooden or fiberglass broom handle, to knock the victim away from the voltage source.

If the victim is not breathing, artificial respiration may be necessary to get the heart and lungs operating again.

Ladders

You may often find that you need a ladder to reach a work area. When choosing a ladder, make sure you select one that matches your requirements. Self-supporting ladders, such as stepladders, should be used only if the work area is not near a vertical support such as a wall and the floor beneath the work area is even and firm.

Non-self-supporting ladders, such as extension ladders, are useful when there is a firm vertical support near the work area and there is a stable, nonslip surface on which to rest the ladder. When setting up a non-self-supporting ladder, it is important to place it at an angle of 751/2° to support your weight and be stable. A good rule for finding the proper angle is to divide the working height of the ladder (the length of the ladder from the feet to the top support) by 4, and place the feet of the ladder that distance from the wall. For example, if the ladder is 12 feet tall, the bottom should be 3 feet from the wall.

Be sure that the ladder you select can carry your weight along with the weight of any tools and equipment you are carrying. Read the labels and warnings on the ladder you select to make sure that it is the right one for the work you are performing.

If you are working near live electrical systems, be sure to use a nonconducting ladder of wood or fiberglass. If you are working near high heat, select an aluminum ladder to avoid scorching or melting your only means of support.

In the work area, place the ladder so that you can work comfortably without having to reach too high or too far to the side. Overreaching can cause you to lose your balance and fall or place too much weight above or to the side of the ladder, causing the entire ladder to come down. If your work area extends beyond a comfortable reach, climb down the ladder and move it. Do not try to “walk” the ladder to a new work area.

Inspect ladders before using them. Make sure the rungs and rails are in good shape and are not split, broken, or bent. Make sure all fittings and fasteners are secure and that all locking mechanisms are working properly.

When carrying a ladder to the worksite, reach through the rail and balance it on your shoulder. Be aware of obstacles and corners as you carry it, and make sure others are aware that you have an awkward load, especially if you are walking through hallways or other limited visibility areas.

Trenches

If you are working on a fiber system in a trench, be sure the trench is properly dug and shored before entering it. Never work in a trench without someone else around, in case of a collapse.

If you have never worked in a trench before, learn the proper way to enter and exit a trench. Always use a ladder. Never jump into a trench or try to climb down the sides. You could trigger a collapse.

If you witness a collapse and others are trapped but not in immediate danger, do not try to dig them out yourself. You risk making the problem worse. Get help immediately. Special training is required to recover victims from a trench collapse, so leave it to the experts.

Injury

Injuries can be caused by misuse of tools, fibers penetrating your skin or eyes, burns, falls, or any number of other mishaps. Make sure that you and your co-workers know the location of first-aid kits in your work area. Also, make sure you know how to reach emergency personnel. If you are on a new job site, make it a priority to familiarize yourself with emergency procedures and contact information.

Chemical Exposure

Accidental chemical exposure can result in anything from temporary discomfort to permanent injury or death. The first few seconds of an emergency involving chemical exposure can be critical in the victim's recovery.

If the chemical is splashed on the skin or in the eyes, flush the affected area with clean water immediately, using a shower or eyewash station if available. Continue flushing the area for at least 15 minutes. This washes the chemical away but also dilutes its effects if it has been absorbed by the skin or eyes.

In case of inhalation, move the victim to fresh air immediately and call for medical attention. If a chemical has been accidentally swallowed, induce vomiting unless the chemical is corrosive and could damage the esophagus and throat as it comes back up. Use a neutralizing liquid such as milk to dilute corrosive chemicals if they have been swallowed, and seek medical attention immediately.

Fire

If a fire breaks out in your work area, it may be small enough for you to handle alone. If it is small, you can smother it with a damp cloth. If it is larger, but contained in a trash can or other enclosure, use the appropriate fire extinguisher for the material that is burning.

To use a fire extinguisher properly, remember the acronym PASS as you use the following procedure:

1. Pull Pull the pin from the fire extinguisher trigger.
2. Aim Aim the extinguisher at the base of the fire.
3. Squeeze Squeeze the handle firmly to activate the extinguisher.
4. Sweep Sweep the extinguisher discharge at the base of the fire until the flames are out.

Do not give the fire a chance to trap you. If you think that the extinguisher will not put out the fire completely and there is a risk that your exit will be cut off, leave immediately and call for help. You can do more good with a phone call than you can in a failed attempt at being a hero.

Classify a Light Source Based on Optical Output Power and Wavelength

The OSHA Technical Manual describes the Optical Fiber Service Group (SG) Designations based on ANSI Z136.2. These SG designations relate to the potential for ocular hazards to occur only when the OFCS is being serviced. OSHA also classifies standard laser systems.

An OFCS does not fall into any of the SG designations defined in the OSHA Technical Manual because during servicing it is possible to be exposed to laser emissions greater than 750mW. What classification would be assigned to this OFCS based on the OSHA Technical Manual?

If the total power for an OFCS is at or above 0.5W, it does not meet the criteria for an optical fiber SG designation and should be treated as a standard laser system. A Class IV laser hazard as defined in the OSHA Technical Manual has a continuous wave output above 500mW, or +27dBm. This OFCS would be Class IV.

Identify the Symptoms of Exposure to Solvents

Solvents can cause organ damage if inhaled or ingested. The molecules that make up most solvents can take the place of oxygen in the bloodstream and find their way to the brain and other organs. As the organs are starved of oxygen, they can become permanently damaged.

Your co-worker spilled a bottle of liquid several minutes ago and now appears impaired. What has your co-worker potentially been exposed to?

Because solvent molecules can displace oxygen molecules in the blood, they can starve the brain of oxygen and give the appearance of intoxication. Your co-worker may have been exposed to a solvent.

Calculate the Proper Distance the Base of a Ladder Should Be from a Wall

Remember non-self-supporting ladders, such as extension ladders, require a firm vertical support near the work area and a stable, nonslip surface on which to rest the ladder. When setting up a non-self-supporting ladder, it is important to place it at an angle of 75 1/2° to support your weight and be stable.

A non-self-supporting ladder is 10' in length. How far should the feet of the ladder be from the wall?

A good rule for finding the proper angle is to divide the working height of the ladder (the length of the ladder from the feet to the top support) by 4, and place the feet of the ladder that distance from the wall. This ladder was 10' in length so the ladder's feet should be 2.5' from the wall.