Using Commas

Using Commas Use a comma---to set off introductory words and phrases. For reasons of safety, only company employees are allowed in the work area. Whether the workers like it or not, they must wear hard hats in this area. On Wednesday, please try to be at the site by 7:30 a.m.

--when a dependent clause comes first in a complex sentence. When it is safe, air normally contains about 21% oxygen and 79% nitrogen. After you have tested the air and found it safe, it is still prudent to have a breathing device with you.

--between the clauses linked by a coordinating conjunction (and, or, nor, but, so, for, while, yet) in a compound sentence (containing two or more independent clauses). One worker moved the truck into the on-coming lane, and a second worker stopped the on-coming traffic. (Without the comma, a serious accident might result.)

--to set off a nonrestrictive modifier. Nonrestrictive: Vapor, which is the gaseous phase of a substance, can be injurious. Restrictive: Vapors or gases that are noxious are directly or indirectly harmful or destructive to the health or life of humans. Gases that are non-poisonous may asphyxiate simply by mechanically excluding oxygen. --to set off explanatory material or definitions. Workers must be outfitted with safety gear, hard hat and breathing equipment, before entering the sewer.

--to separate introductory words or phrases, where confusion might result. As foreman, Petersen has been a great success.

--to set off an interjection or a transitional element. Interjection: There are numerous hazards, unfortunately, that can cause physical injury in waste treatment plants.

Transition word: An atmosphere containing less than 19.5% oxygen by volume, however, is decidedly dangerous for humans

--to separate series of words, phrases, or clauses. Natural gas, gasoline vapors, and hydrogen sulfide are all noxious hazards in the confined space of a sewer. The places which are most likely to harbor dangerous noxious gases or oxygen deficiency are sewers with solid manhole covers, tightlycovered pits or chambers, and deep tanks or pump suction wells. Note: The comma before the and in a series is optional. However, most technical writers use it consistently for clarity.

--to separate a series of coordinate adjectives. Small, airless underground spaces are particularly susceptible to noxious gas buildup Note: The comma here can be seen as taking the place of and. The words small and airless are called coordinate adjectives in that they both describe the noun phrase underground spaces. Therefore there is not comma to set off the word underground.

Do not use a comma---to separate two independent clauses…creating a comma splice. Wrong: The term sewer gas is a misnomer, it is not a single gas. Correct: The term sewer gas is a misnomer since it is not a single gas. Wrong: It is actually sewage sludge gas with a high content of carbon dioxide and varying amounts of methane, hydrogen, hydrogen sulfide and a small amount of oxygen, the hazard is usually from an explosive mixture of methane and oxygen or from an oxygen deficiency. Correct: It is actually sewage sludge gas with a high content of carbon dioxide and varying amounts of methane, hydrogen, hydrogen sulfide and a small amount of oxygen. The hazard is usually from an explosive mixture of methane and oxygen or from an oxygen deficiency.

--when it separates a subject from its verb. Wrong: Detection of an existing gas or vapor hazard and then taking steps to remove or to protect against it, are the sure ways to prevent accidents and loss of life. Correct: Detection of an existing gas or vapor hazard and then taking steps to remove or to protect against it are the sure ways to prevent accidents and loss of life.

(c)David Tillyer

Prevention of Physical Injury This is from a State of New York instruction manual for Waste Treatment Plant Operators. The capital letters, end punctuation, and commas have been removed. Please print out these safety instructions and replace the capital letters, end punctuation, and commas. Then consult the answer key to check your work.

the major cause of injuries is slips and falls tools parts and other things should not be left lying around grease droppings oil sludge and especially polymers should be cleaned up as soon as possible warning signs railings and covers in place can protect against low piping open tanks and open manholes or hatches the simple knowledge of proper lifting techniques bending the knees and lifting with muscles of the legs can save many strained or injured backs Manholes for work in manholes in streets safety requires full protective measures from traffic hazards as well as from the hazards of explosive gases hydrogen sulfide or the lack of oxygen in the manhole or sewer warning signs and barricades should be set up at suitable distances on each side of the manhole on busy streets it may be desirable to station workers to flag down and detour fast-moving vehicles on wide multi-lane streets the service truck can be stationed on the side of the manhole toward on-coming traffic it is important that sufficient workers be provided for the job at hand there should be at least two workers at the top when one goes below a cage or guard device around the manhole adds protection and aids entering and leaving the ventilation hole or lifting notch when lifting a manhole cover a pick-axe may slip and cause injury or if struck hard may give off an igniting spark unless a cover is very heavy it is safer for one person to handle

it alone

before entering a manhole the confined atmosphere should always be tested for the presence of explosive gases hydrogen sulfide and oxygen deficiency after determining that the conditions are safe for entry positive forced air ventilation should be started and operated continually whenever a worker is in the manhole or sewer there should also be a continuous sampling of the atmosphere with a visual signal alarm device kept near the worker

before descending into a manhole note should be taken of the width spacing and arrangement of manhole rungs and if they are staggered particular care must be taken to get started with the proper foot and to avoid falling steel rungs may lose their galvanizing and become dangerously corroded each rung should be tested during descent while the worker distributes weight evenly between feet and arms a safer means of entry would be to use a manhole ladder which can be carried on the service truck the ladder should extend about three feet above the street surface as the worker climbs down even with a separate manhole ladder the worker should use caution as his or her boots may have oil on the soles causing a fall

Safety Harness on small sewers no one should enter a manhole deeper than the height of the chin without wearing an approved parachute-type safety harness with rope attached in an emergency when a safety belt may not be at hand a stout rope tied snugly under the arms with a

bowline or other non-slip knot may be the means of saving a life in either case at least two people should be a the top of a manhole at all times when a third worker is inside in order to handle the life line and help the worker if necessary a safety harness should also be worn when entering any enclosed spaces around a sewage treatment plant such as pump suction wells empty digestion tanks sludge storage wells or any other space where access is difficult and assistance may be needed to climb out. Back to the lesson

Prevention of Physical Injury -- Answer Key The major cause of injuries is slips and falls. Tools, parts, and other things should not be left lying around. Grease droppings, oil, sludge, and especially polymers should be cleaned up as soon as possible. Warning signs, railings, and covers in place can protect against low piping, open tanks, and open manholes or hatches. The simple knowledge of proper lifting techniques, bending the knees and lifting with muscles of the legs, can save many strained or injured backs. Manholes For work in manholes in streets, safety requires full protective measures from traffic hazards as well as from the hazards of explosive gases, hydrogen sulfide, or the lack of oxygen in the manhole or sewer. Warning signs and barricades should be set up at suitable distances on each side of the manhole. On busy streets, it may be desirable to station workers to flag down and detour fastmoving vehicles. On wide, multi-lane streets, the service truck can be stationed on the side of the manhole toward on-coming traffic. It is important that sufficient workers be provided for the job at hand. There should be at least two workers at the top when one goes below. A cage or guard device around the manhole adds protection and aids entering and leaving the ventilation hole or lifting notch. When lifting a manhole cover, a pick-axe may slip and cause injury or, if struck hard, may give off an igniting spark. Unless a cover is very heavy, it is safer for one person to handle it alone.

Before entering a manhole, the confined atmosphere should always be tested for the presence of explosive gases, hydrogen sulfide, and oxygen deficiency. After determining that the conditions are safe for entry, positive forced air ventilation should be started and operated continually whenever a worker is in the manhole or sewer. There should also be a continuous sampling of the atmosphere with a visual signal alarm device kept near the worker. Before descending into a manhole, note should be taken of the width, spacing, and arrangement of manhole rungs and, if they are staggered, particular care must be taken to get started with the proper foot and to avoid falling. Steel rungs may lose their galvanizing and become dangerously corroded. Each rung should be tested during descent while the worker distributes weight evenly between feet and arms. A safer means of entry would be to use a manhole ladder, which can be carried on the service truck. The ladder should extend about three feet above the street surface as the worker climbs down. Even with a separate manhole ladder, the worker should use caution as his or her boots may have oil on the soles, causing a fall. Safety Harness On small sewers, no one should enter a manhole deeper than the height of the chin without wearing an approved parachute-type safety harness with rope attached. In an emergency, when a safety belt may not be at hand, a stout rope tied snugly under the arms with a bowline or other non-slip knot may be the means of saving a life. In either case, at least two people should be a the top of a manhole at all times when a third worker is inside in order to handle the life line and help the worker if necessary. A safety harness should also be worn when entering any enclosed spaces around a sewage treatment plant, such as pump suction wells, empty digestion tanks, sludge storage wells or any other space where access is difficult and assistance may be needed to climb out.