Did You Ever Wonder?

By David H. Glabe, P.E. / May 31, 2006

Did you ever wonder where the OSHA standards came from?  For that matter, did you ever wonder where OSHA came from?  How did the scaffold standards come to be?  Did they always exist?  Have you ever heard of Letters of Interpretation and Directives?  You might be surprised at the answers.


The Federal Occupational Safety and Health Administration, OSHA, was created in 1970 when the United States Congress passed a law addressing workplace injuries and deaths.  At the time, multiple rules, standards, and laws enforced by multiple agencies existed but were not consistently enforced.  For that matter they weren’t very consistent or standard either.  What was legal in one state wasn’t necessarily legal in another.  What was seen as a safe work practice in Texas just might not be safe in Illinois.  Statistics illustrated the state of affairs in 1970: Serious injuries and deaths continued to climb.  The 91st Congress took action by passing Public Law 91-596 on December 29, 1970.  This law required, in part, that employers shall:


“(1) Furnish to each of his/her employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his/her employees;  (2) Comply with occupational safety and health standards promulgated under this Act.”


The law also requires that employees “shall comply with occupational safety and health standards and all rules, regulations, and orders issued pursuant to this Act which are applicable to his/her own actions and conduct.”


Passing the law was the easy part since safety can sometimes be rather subjective.  What constitutes a safe place of employment?  Your idea of a safe workplace may not agree with another’s opinion.  To bring some consistency to the concept of safe workplace, the law also established an agency within the Department of Labor to develop standards that determined the minimum requirements for a safe workplace, and provide the enforcement to make the standards effective.  Thus was born the Occupational Safety and Health Administration, OSHA.  Also established at the same time was the OSHA Training Institute, OTI, to assist employers in providing training for employees.


How do you write regulations that everybody can agree on?  First, you have to be real good at writing standards.  Secondly, you have to make sure that the regulation, or standard, is applicable to the specific hazard and will not be misinterpreted.  As a matter of fact, in a perfect world, no interpretation is required and everybody agrees on the meaning of the standard and the proper application of that specific standard.  Too bad it’s not a perfect world.


Luckily, consensus standards and other rules existed prior to the establishment of OSHA.  In other words, there was a foundation on which to build a system of mandatory standards.  The American National Standards Institute, ANSI, had developed many standards prior to OSHA and for that matter, continues to develop consensus standards today.  The ANSI standards are based on earlier standards and guidelines that were developed by insurance companies going back to the turn of the last century (that’s like a hundred years ago!)  Scaffold standards can be traced back to the 1920’s when at least one insurance company issued guidelines for scaffolding and other construction activities.


The scaffold standards have evolved since 1971 when OSHA developed their first scaffold standard.  In fact, in 1977 OSHA decided that the first scaffold standard could use some improvement and consequently started reviewing and rewriting the scaffold standard.  This was a long arduous process but finally in 1996 the present standard was issued.  However, as good as the present standard is, clarification is required from time to time, especially when attempting to apply the scaffold standard to s specific situation that doesn’t seem to “fit” any standards.  This is where Letters of Interpretation come into the picture.  Anybody can write to OSHA and ask for a Letter of Interpretation.  Once the request is submitted, OSHA carefully reviews the standard and other available information to determine an interpretation that meets the intent of the standard.  A letter is published and becomes enforceable just like the standard itself.


Directives are another tool that OSHA uses in conjunction with the standards.  Directives are different than Letters of Interpretation. The purpose of the Enforcement Directive for Scaffolds, for example, is to give guidance to OSHA compliance officers for enforcing the scaffold standards.  This directive is useful information and, just like the Letters of Interpretation, is available on the OSHA website, www.OSHA.gov.


So, is it a wonder that the OSHA scaffold standards are applicable to many scaffolds?  Not really, once you realize that many people with a lot of expertise have been involved in the development of standards over the years and still are today.  The Scaffold Industry Association, SIA, has been intensely involved in the development of many scaffold related standards since the association’s inception.  Mr. Jerry Towse, first president of the SIA, recalls:  “We (the SIA) were concerned when the first OSHA scaffold standards were issued because they inadequately addressed the industry’s concerns about safety.  At that time, it was decided the association should be proactive in standard development.”   This involvement includes the ANSI aerial lift standards, (the A92 series of standards), the ANSI scaffold standards, (A10.8), and the present OSHA standards.  Like the SIA, the Scaffolding, Shoring, and Forming Institute, SSFI, has also been involved with scaffold standards since that association’s creation in 1960.


You may think the OSHA standards are deficient but I suggest this:  try writing a standard or two.  You’ll find out how hard it is to be precise yet broad enough to apply universally.  You should be thankful to all the involved people who have selfishly contributed to the process.

s�_ae� (�  For Tubular Welded Frame Scaffolds, for example, these are the differences:



  1. The general industry standards require the use of a guardrail system and toeboard.  The construction industry standards allow the use of a guardrail system or a personal fall protection system.  Also, other forms of falling object protection, besides toeboards, are allowed;
  2. The general industry standards require that the toprail be installed between 36 and 42 inches.  The construction industry standards require the toprail to be installed between 38 and 45 inches;
  3. The general industry standards require that all frame scaffolds be erected by competent and experienced personnel. The construction industry standards require that scaffolds be erected under the supervision of a competent person qualified in scaffold erection, using experienced and trained employees.
  4. The general industry standards require periodic inspections of scaffold equipment.  The construction industry standards require inspections by a competent person prior to each workshift.


This short dissertation illustrates the significant differences between the requirements of the two standards; use it to recognize that you cannot take the general industry standards and apply them to a construction industry application or use the construction industry standards in a general industry application.  It is necessary to identify which standards apply for the specific application.  And of course, no matter which standards apply, it is a safe scaffold that is required.

Tags: ANSI forming OSHA creation OSHA history OSHA Standards & Regulations Public Law 91-596 Resources SSFI

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David H. Glabe, P.E.

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