- Standard Number:
OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.
December 22, 2003
Mr. Doug Schneider
Safety Solutions, Inc.
1045 S. 217th Street
Elkhorn, NE 68022
Re: In steel erection, is it permissible to designate an entire floor of a building as a Controlled Decking Zone (CDZ) and limit access to the CDZ by limiting access to that entire floor?
Dear Mr. Schneider:
This is in response to your letter dated December 19, 2002, to the Occupational Safety and Health Administration (OSHA). You ask for guidance regarding controlled decking zones in steel erection. We apologize for the delay in providing a response.
We have paraphrased your question as follows:
Question: Scenario: A multi-story building is being constructed. The metal floor decking has been completely installed on floor 2. No decking has been installed on floor 3. Decking operations have been completed on floor 4. Is it permissible to designate all of floor 3 as a Controlled Decking Zone (CDZ) and limit access to the CDZ by limiting access to that entire floor? If so, is marking the perimeter of the entire floor with control lines still required?
The Steel Erection standard, §1926.760, allows the use of a specific type of controlled access zone (CAZ), called a controlled decking zone (CDZ), for steel decking work. As stated in the preamble, "An important aspect of a CDZ is controlled access." [Emphasis added.] Sections 1926.760(c)(3) and 1926.760(c)(5) state:
(3) The boundaries of a CDZ shall be designated and clearly marked. The CDZ shall not be more than 90 feet (27.4 m) wide and 90 feet (27.4 m) deep from any leading edge. The CDZ shall be marked by the use of control lines or the equivalent. Examples of acceptable procedures for demarcating CDZs can be found in Appendix D to this subpart. [Emphasis added.]
* * *
(5) Unsecured decking in a CDZ shall not exceed 3,000 square feet (914.4 m2).
Under these provisions, the CDZ must be "clearly ... marked by the use of control lines or the equivalent."1 Restricting access to an entire floor would be "equivalent" to control lines where both of the following conditions are met: (1) the points of access to the floor are limited and can be controlled (such as where the only means of access to the floor is by a single ladder); and (2) each point of access (such as the base of a ladder leading to the floor) is marked with a warning sign indicating that access is restricted to Controlled Decking Zone workers.
Another requirement of the CDZ is that it not be greater than 90 feet x 90 feet. However, it is likely that in many instances an entire floor will be larger than 90' x 90'. There are two purposes of this requirement.
One purpose is to reduce the likelihood that non-deckers/other trades who are on the same floor as the CDZ will ignore the control lines and enter the CDZ to do non-decking work (if the CDZ is larger than 90' x 90', there may be an increased likelihood that the CDZ will cause an undue delay in those non-decking workers being able to do their tasks).
Preventing non-deckers/other trades from entering the floor at all is likely to be a more effective way of decreasing the likelihood that they will enter into the CDZ than limiting the size of the CDZ to 90' x 90' on a floor where other trades are working. With access to the entire floor limited to only the CDZ workers, there would be no workers near the CDZ tempted to enter into it.
The second purpose is to limit the size of the area where workers are unprotected by conventional fall protection. This purpose is met where conventional fall protection is in place to protect workers once the decking has been initially installed in an area "90 feet wide and 90 feet deep from any leading edge."
In sum, where the entire floor is designated as a CDZ, the failure to use control lines around the entire floor and the failure to limit the size of the CDZ to 90' x 90' would be considered a de minimis violation2 of §1926.760(c)(3)3 where the following conditions are met:
- The points of access to the floor are limited and can be controlled (such as where the only means of access to the floor is by a single ladder);
- Each point of access (such as the base of a ladder leading to the floor) is marked with a warning sign indicating that access is restricted to Controlled Decking Zone workers; and
- Conventional fall protection, such as perimeter guardrails and covers or guardrails around holes or openings, is in place to protect workers in the area that is "90 feet wide and 90 feet deep from any leading edge" in which the decking has been initially installed.
An example of the type of sequence we are describing, where an entire floor is designated as a CDZ in accordance with what we have described above, is illustrated [below]:
(Grey indicates initially attached decking; dotted lines indicate guardrails)
(1) Entire floor is designated as a CDZ, with limited access points, and use of those access points is limited to CDZ workers, as described above.
(2) Initial decking work takes place in the first 90' x 90' area:
(3) Once that 90' x 90' area is initially decked, conventional fall protection is required for that area:
If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Compliance Assistance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.
Russell B. Swanson, Director
Directorate of Construction
Question 48: Section 1926.760(c)(3) & Appendix D: The suggested example in the appendix states that "any other means that restricts access" may be used instead of control lines. What are some examples of other means?
Answer: Section 1926.760(c)(3) requires that the boundaries of the CDZ be marked "by the use of control lines or the equivalent." In a CDZ, the control line restricts access by visually warning employees of an unprotected area (66 FR 5247). Control lines can be made of rope, wire, tape, or other equivalent materials, but they must clearly designate the CDZ. Examples of other acceptable methods would be a perimeter wall, guardrail system, or even a restraint system rigged so that non-leading edge workers could not access the area. In contrast, a line painted on the floor would not be considered to be equivalent to control lines since it would be less visible than a control line.
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2 De minimis violations are violations of standards that do not affect safety or health. Citations are not issued for de minimis violations, and no corrective action is required. [ back to text ]
3 This is not to be confused with the requirement in 1926.760(c)(5) limiting the amount of unsecured decking to 3,000 square feet -- that requirement must still be met. [ back to text ]