3 2 ea! ~ ; oa In this age when a worker is told he is “too old” at 40 for a new _ job, another problem has been creeping into our industry: — NOISE. Deafness has insidiously undermined the ability of many of our members to stay in the employment race. We urge our Joint Safety Committees to pay particular attention ’ to this problem. Be on the alert for high intensity sound in your opera- tion. If you are not sure of the potential dangers, call in the Industrial Hygiene Department of the Workmen’s Compensation Board. _» REMEMBER:—INDUSTRIAL DEAFNESS IS NOT THE ONLY HAZARD. NOISE CAN RESULT IN MENTAL FATIGUE AND DECREASED ALERT- _ NESS. THEREFORE, NOISE CAN KILL YOU. (WE REPRODUCE HERE, | SOME OF THE FACTS ABOUT INDUSTRIAL NOISE PUT OUT BY THE > W.C.B.). PLEASE NOTE THAT NO ONE HAS SUGGESTED HOW YOU CAN GET COMPENSATION ONCE YOU HAVE BECOME DEAF THROUGH PROLONGED EXPOSURE TO NOISE. PREVENTION MUST BE THE ANSWER. 4 CHARACTERISTICS OF NOISE Sound is defined as a wave motion in air. Sound waves are set up by any vibrating body and they travel through air at a definite speed. If their frequency and intensity are within certain ranges, they produce the’ sensation of hearing. Noise is the common term used to denote unwanted sound. The frequency of sound is defined as the number of complete vibrations {eycles) of the sound wave per Second. Frequency determines the pitch of a sound. Low pitch sounds have a low frequency, and high pitch sounds a high frequency. Frequencies below 18 cycles per second and above 18,000 cycles per second are usually beyond the range of normal hearing. The intensity of sound is the amount of energy in the sound wave, and | the sound level is usually expressed in decibels. Intensity is interpreted as » loudness by the lisfener. The threshold of hearing, or the weakest sound that ean be heard is zero decibles, and the threshold of pain is 130 decibels. TYPICAL SOUND LEVELS: Decibels Jet motor at 75 feet - - - - 130 *Rock drills - - - - - = = W115 . Kraft paper winder = oe oe =e 1 *Wood chippers - - - - - - 110 Newsprint machine - - - - - 108 7 *Cutoff saw- = - - 7 = 3 95 Street corner traffic, large city - ~~ 75 Swpicdioiice = e me 60 Nermal conversation in average living reom- - - = 40 *Note that according to the graph below even the cut-off saw is in the danger area. Ear pro- tection is mandatory for wood chippers and on rock drills. : BROAD-BAND NOISE LEVEL CRITERIA FOR HEARING CONSERVATION THE WESTERN CANADIAN LUMBER WORKER A Message To Top Management By BOB ROSS Regional Safety Director > With some notable exceptions you are nof getting through to the man on the job on Safety because you have not yet convinced your super- visors. Our members do not believe you mean business. On the contrary, they often hear much talk and see very little action on accident pre- vention. Your foremen and supervisors are your re- flection on the job where the accidents occur. © Some are not certain that only a safe op- eration can produce efficiently. ® Some have not yet been trained in safe supervision. © Some do not realize time spent now on safe job procedure will save much more time later. © Some still think that speed-up is the answer to better production. @ Some still fail to appreciate that concealing injuries only delays the collapse of their departments. You know these things. Your Association Accident Prevention Depart- ment knows them. We know them. GET THROUGH TO YOUR PEOPLE OUR PEOPLE WILL CO-OPERATE The relationship between noise exposure and hearing loss is still being studied, particularly for non-continuous noise identified as impact noise and intermittent noise. Criteria for part time exposures to high level noise have also been proposed, HOW CAN NOISE BE CONTROLLED? Where sound level measurements show that a noise problem exists, hearing conservation programmes are recommended. In a hearing cohservation programme the most effective method of control is the reduction of the noise at the source. i The principles of sound control concern themselves with the control of vibrations in any transmitting medium, the air, walls, floors, or piping. Noisy machines should be continually maintained in proper repair and kept in good adjustment. If practicable, the machine should be redesigned for quieter op- eration. Machines can be mounted on resilient supports in an attempt to reduce low frequency noise and floor vibration. Another method of noise control is by shielding and segregation of noisy operations. In addition, absorbent lined booths can be built around the noisiest machines. Further aid to the general workroom can be obtained by erecting baffles to act as barriers against sound transmission in a given direction, Noise control through sound-conditioning of noisy areas is an effective method. Mufflers and silencers may be used on noise producing gases flowing through pipes, and find application in a wide variety of equipment. Their design is often complicated by the necessity of dealing with high temperatures and high pressures. ttt it