Permit System

Before entry, a permit system has to be developed to ensure that the space is safe to enter and entrants, attendants, and the supervisor are prepared. A designated and trained entry supervisor must authorize the entry, prepare and sign written permits, order corrective measures if necessary, and cancel permits when work is completed. Permits must be available to all permit space entrants at the time of entry and should extend only for the duration of the task. Cancelled permits have to be retained for a year to use in a review of the confined space program.

Entry permit

An entry permit documents the essential elements of an entry and must include:

1.     Identification of the space;

2.     Purpose of the entry;

3.     Date and duration of the permit;

4.     Names of authorized entrants;

5.     Names of attendants and the entry supervisor;

6.     List of hazards in the space;

7.     List of measures to isolate the space and eliminate or control the hazards;

8.     Acceptable entry conditions;

9.     Results of tests initialed by the person(s) performing the tests;

10.  Rescue and emergency services available and the means to summon them;

11.  Communication procedures for attendants and entrants;

12.  Equipment used for the entry (respirators, communication, alarms, etc.);

13.  Any other necessary information; and

14.  Additional permits (such as for hot work).

Permit-Required Confined Spaces

The standard covers general industry workers, including over 1.6 million who enter confined spaces each year and an additional 10.6 million employed at the 240,000 covered worksites. When the standard was implemented, OSHA expected it to prevent about 85 percent of the deaths and injuries caused by confined space entry and rescue — an estimated 54 deaths and 10,000 injuries each year. It does not apply to agriculture, construction, or shipyard employment.

What is a confined space?

A confined space is defined as an area which:

1.     Has adequate size and configuration for an employee to enter and perform work;

2.     Has limited or restricted means to enter and exit; and

3.     Is not designed for continuous employee occupancy.

What is a permit-required confined space?

A permit-required confined space is defined as a confined space having one or more of the following characteristics:

1.     Contains or has the potential to contain a hazardous atmosphere;

2.     Contains material that has the potential for engulfing an entrant;

3.     Has an internal configuration that could trap or asphyxiate an entrant by inwardly converging walls or sloping floor; or

4.     Contains any othe recognized serious safety or health hazard.

Cellular Manufacturing Systems | Machine Guarding

A development in manufacturing technology has given rise to a manufacturing concept known as Manufacturing Systems/Cells, or Cellular Manufacturing Systems. These systems of integrated industrial machines, linked by a material handling system and operated by (controlled by) a programmable electronic system (computer) are capable of manufacturing discrete parts or assemblies. The safety of employees exposed to these systems is important.

Because a system is to be safeguarded, it is logical that a system hazard analysis will yield the parameters of the safeguarding system required. Figures 1 through 3 depict typical cellular system concepts and safeguarding considerations.

Figure 1: Typical manufacturing system/cell using a robot as the material handling system showing perimeter marking/barrier, fixed barriers with interlocked gates, presence sensing devices, warning devices, and additional system emergency stop devices

Figure 2: Manufacturing system composed of several cells

Figure 3: Areas to be considered for safeguarding

ANSI B11.20, should be referred to for assistance when a cellular manufacturing system is envisioned.