An Explanation of Table 1
We’re ready to tackle Table 1 of the Construction Standard.
Table 1 was developed specifically for Construction to give direct guidance on ways to reduce silica emissions to levels below the 25 microgram action level. Although it looks rather intimidating and difficult to follow, it’s really quite easy, so let’s take a closer look. By the end of this article and working though my examples, you’ll be a Table 1 Expert.
Table 1 consists of 18 rows with each row representing a different piece of equipment. Within each row there are three columns: the equipment column, the engineering controls column, and the respiratory protection column. The respiratory protection column is further divided into two sub-columns – one for work less than four hours, and one for work greater than four hours.
Here’s how you read it. First, go to the row for the equipment you are using. Second, look at the engineering controls that are identified in Column 2 of that row. Third, determine how long your worker will be doing that task. Then you can determine how much respiratory protection is needed to be in compliance with the rule.
You will be removing three sections of concrete in an outdoor parking lot with a jack-hammer. Each section will take about one hour of actual jack-hammering. A standard, air-driven jack-hammer with a continuous water spray will be utilized to complete the task.
Question: According to Table 1, do you need a respirator? If so, what kind?
Answer: No. Jack-hammers and power chipping tools is listed in Row 10 of Table 1. In the second column of Table 1, you are using a water spray, and you are working outdoors. Since the job is less than four hours, no respirator is required.
Same project except this time you are jack-hammering in an indoor warehouse. Same jack-hammer, same water spray, same length of time.
Question: Do you need to wear a respirator, and if so, what kind?
Answer: Yes! Same Row 10 of Table 1 except this time you are working indoors. Working indoors requires you to wear a respirator regardless of time. In this case, you would need to wear a respirator with an Assigned Protection Factor (APF) of 10 which is a half-face, negative pressure respirator.
One more thing
There’s one other thing about Table 1. If you are working multiple tasks and the total length exceeds four hours, then the respirator requirement for each task is the one for greater than four hours.
In our example above, same jack-hammer, same total number of concrete sections except this time, you are going to do both the parking lot and the warehouse in the same day (six hours total jack-hammering time). Since the total time of all tasks exceeds four hours, you need to wear the respirator required for each task as if each task were going to take more than four hours. Jack-hammering for more than four hours, whether indoors or outdoors, requires a respirator with an APF of 10. Therefore, you need to wear a respirator for all the jack-hammering – both indoors and outdoors.
So you see, Table 1 is really not that hard.
Next: What do you do if you can’t or don’t use Table 1?