1. Activity 4: Hazard Recognition
Chapter 9, pp 6, 7, & 8

2. You are Chris Worker, a construction worker working as part of a mixed crew on a CERCLA hazardous waste site erecting an entombment chamber for 55-gallon drums. The site characterization and analysis crew has finished work. You are working for the contractor hired to clean up the site and are dressed in Level C protection (air-purifying respirators and splash suits). Soon after starting the excavation, you spotted unmarked drums buried where you were going to build the chamber. Upon closer examination, these drums are corroded and appear to be leaking. This spot was listed on the site map as having no barrels and was therefore not included in the initial site characterization and analysis.
Participants are not meant to be able to read this slide and the following two. This is a copy of the activity that appears on page 3-61 of their manual. The instructor should read the activity aloud to the participants and answer any questions before the small groups begin work.

3. To save time and stay on schedule, your supervisor decides to go ahead and use the crew to clear these drums without any additional assessment, even though they weren’t included in the original site analysis or plan.
You refused to do any work with the buried drums until the contractor had the drums sampled and all the hazards identified. Your employer did this and told you not to worry. They sampled the nearest drum and found that it contained waste phosphorus trichloride.

4. Therefore, your team still dressed in Level C protection with HEPA (High Efficiency
Particulate Air) filters, could now overpack the drums and store them to one side while you continued building the concrete forms. You checked the NIOSH Pocket Guide and gathered information about this chemical.
As you were finishing your research in the NIOSH Pocket Guide, your foreman came up to tell you that there was reason to believe that some of the barrels also contained TDI, also known as toluene-2,4-diisocyanate. You immediately returned to your Pocket Guide to get some information on this newly identified chemical.

5. 1. What are the physical characteristics of toluene-2,4
Colorless to pale-yellow solid or liquid (above 71◦F) with a sharp, pungent odor
A discussion may be initiated as to what constitutes “pungent”. Possible answers may include; sharp; strong; unpleasant

6. 2. What is the UEL
9.5%
and LEL
0.9%
of this chemical?
3. What is the flashpoint?
260◦F
What does this mean?
At 260◦F, this chemical will give off enough vapors to burn if there is sufficient oxygen and an ignition source

7. 5. What us the vapor Pressure of this chemical? (77◦F) 0.01mmHg
What is the PEL of this chemical?
C 0.02 ppm
What is IDLH of this chemical?
Ca 2.5 ppm
The answers on this slide can be used as a review and will be covered on the next slide.

8. What do these numbers mean?
VP – Low vapor pressure – Does not enter the air rapidly
PEL – Permissible Exposure limit – extremely low
C – Ceiling – Never above this level, even for an instant
IDLH – Immediately dangerous to life and health.
Will cause irreversible health effects in 30 minute or less,
or will limit the ability to self-rescue

9. 6. What are this chemical’s Target Organs?
Eyes, skin, Resp Sys (in animals: pancreas, liver, mammary gland, circulatory sys & skin tumors) 7. What are the Routes of Entry to the body? Inh, Ing, Con
Participants may need to refer to the Terms and Definitions from the NIOSH Pocket Guide

10. 8. What level of protection would you want to be wearing for your job?
Reason? B
Reason? C
Reason? D
Reason?
When asking this question, have the group(s) stating that they would want Level A give their reasons. The same with B, and so on.
Remember, A and B could both be correct, depending on the reasoning.
C would be incorrect because of the “Leaking” which is an unknown concentration.
D would never be acceptable as there is no protection on Level D.

11. 9. Using the above information, what concerns, if any, would you have about entering the excavation to overpack these leaking drums?
MW 174.2
Reacts with Strong oxidizer
Reacts with Acids & Bases W
Prevent skin contact
Prevent eye contact
PEL 0.5 ppm
IDLH 25 ppm
Irrit eyes, skin, nose, throat, etc, etc, etc.
Pulm edema Ca
Answers to this question can be recorded on a whiteboard or easel pad.
Do not have one group give all of their answers. Move from group to group until all answers have been given.
The above list is only a partial list and participants may have additional answers.
The number one reason should be the last point where the exercise states that the foreman has reason to believe that some of the drums may contain phosphorus trichloride.
Have reason to believe????!