Safety Test 1 September 11 Flashcards
slips, trips, and falls are the ___ leading cause of occupational fatalities, and how many people is this per year?
- 2nd (after motor vehicle accidents)
- 16,000 people die each year as a result of falls
- over 3 million children per year visit ER’s b/c of these
- one of the most preventable injury causes
What causes trips
when the foot is stopped or slowed during its swing phase
slips
result when the foot slips during the weight acceptance phase
weight-acceptance slip
the fall results when the foot slips during the weight acceptance phase
push-off slip
fall results when foot slips during the push off phase
slip resistance defined
dynamic coefficient of friction
the relative force that resists the tendency of the shoe/foot to slide along the walkway surface. it is related to a combination of factors including walkway surface, footwear bottom, and presence of foreign materials between them
slip resistance vs. static coefficient of friction
- not equivalent
- both expressed as unitless measures from 0-1
- slip resistance accounts for the dynamic interaction of footwear with walking surface
- they tend to converge together under dry conditions
- static can overestimate slip resistance under wet conditions
presumed “safe level” of static coefficient of friction (dry)
right around 0.5 (threshold of safety)
why static coefficient of friction cannot be used for wet conditions
can provide an artificially high reading on wet surfaces due to adhesion between test foot and surface, particularly when there’s a long delay before the application of horizontal force
Sticktion problem
- “sticktion” occurs when water is squeezed out between surfaces and creates temporary adhesion between foot and surface
- in some cases, coefficient of friction of wet surface may test higher than same dry surface, when wet surface is actually quite slippery
- this problem can be avoided by eliminating pre-test residence time by applying horizontal and vertical force at same time
protocols for measuring slip resistance
- methods vary
- some accident investigators have misused standards
Injury Potential: falls from height
- walking surface failure
- accidental stepping where no walking surface exists
Other injury potentials
- stepping into openings, people holes, etc.
- stepping off loading docks and other elevated surfaces w/o guards
- deliberate stepping/jumping where no surface exists
- failure of guardrails and other restraining devices
- falls from ladders
Housekeeping - why does OSHA care about this?
- it is actually a law
- bad housekeeping causes slips, trips, fire hazards, etc.
aisles
- must be marked
- must be clear
- must be designed with adequate space for the tasks they’re used for
the rated load limits for a floor, mezzanine, platform, etc. must be:
- determined by a structural professional
- indicated on a permanent plate affixed in obvious position
- never allow loads above capacity
floor and wall openings
- must prevent people/materials from falling through
- can have no more than 1 inch of open surface w/o some kind of cover
- can have a permanent attendant in lieu of railing/cover
Fixed stairs are required if:
- if regular travel from one level to another is required
- if daily travel is required to other levels that contain harmful substances
- if daily carrying of equipment, materials, or tools is required
when can you use ladders instead of stairs?
if the destination is not another level, but a tank, crane, platform, etc.
ladder requirements
- maintain 3 points of contact w/ ladder
- however long ladder is, supposed to be 1/4th that length from wall
- rungs (minimum 12” apart and 16” wide)
- ladder must reach 3 ft above surface
- extension ladder sections must overlap 3 ft (more if > 36 ft long)
- must ascend/descend facing ladder
no step ladder can exceed:
20 ft high
if ladder tips over:
it must be inspected
if fixed ladders exceed 20 ft, must:
must have a landing or platform every 20 ft (every 30 ft if a cage is present)
Pitch of ladder
- 75-90 degrees for portable and fixed ladders
- portable: 4-1 ratio (one foot out for every 4 feet up)
