ASP Exam Study Guide

Confined Spaces

ASP Exam Expectations

As part of the ASP exam, expect general knowledge questions related to hazard identification within confined spaces. The exam questions may focus on potentially hazardous atmospheres, the characteristics of confined spaces, and the differences between permit-required and non permit-required confined spaces. Expect approximately 3 questions on the ASP exam to be related to confined spaces.

ASP Exam Confined Space Definitions

Confined Space – A space which is large enough and configured in a way which allows entry, has limited means of entry and exit, and is not designed for continuous human occupancy.

Permit-Required Confined Space – A confined space which contains or has the potential to contain a hazardous atmosphere, contains a material that could engulf an entrant, has an internal configuration (inwardly sloping walls or floor) that could trap or asphyxiate an entrant, or contains any other recognized serious safety or health hazard.

Employers are required to identify all confined spaces in their workplaces and determine whether the confined spaces are permit-required or not. If permit-required spaces are present, the employer must inform employees of the presence of the permit-required space (often done through the use of signage) and ensure that employees stay out of the space.

Evaluating Hazardous Atmospheres

The presence or potential presence of a hazardous atmosphere would make a confined space a permit-required confined space. The competent person evaluating the confined space should look for:

A potential for oxygen deficient (< 19.5%) or oxygen enriched (>23.5%) atmospheres.
Concentrations of any flammable gas, vapor, or mist in excess of 10% of its LEL.
Combustible dusts in excess of 10% of its LEL.
Atmospheric concentrations of any substance that could cause death, incapacitation, impairment of ability to self rescue, injury or acute illnesses.

The competent person should also consider the work being performed in the space and what atmospheric hazards the work may introduce (such as welding fumes, particulates, etc.) and provide protective measures for any hazards identified.

Evaluating Engulfment Hazards

Engulfment means the surrounding and effective capture of a person by a liquid or finely divided (flowable) solid substance that can be aspirated to cause death by filling or plugging the respiratory system or that can exert enough force on the body to cause death by strangulation, constriction, or crushing, or the substance suffocates the individual. The competent person must consider whether any liquid or flowable solid (such as sand) could enter the space.

Evaluating Entrapment and Small Cross Section Hazards

Spaces which taper to a small cross section can contribute to rapid changes in the atmosphere due to the size of the cross section. Atmospheric hazards that are heavier than air can rapidly settle into these spaces and quickly concentrate toxic substances or displace oxygen. Additionally, spaces with inwardly converging walls can make escape and rescue from the space difficult.

Evaluating Other Safety Hazards

Many other hazards exist which could cause a confined space to become a permit-required confined space. Among these are mechanical, electrical, and pneumatic sources of energy, adjacent operations, temperature and noise extremes, radiation, and biological or environmental hazards. The competent person must evaluate each hazard individually to determine appropriate protective measures prior to entering the space.

Entry Permits and Procedures

Each time a permit-required confined space is entered, entry must be authorized through the use of a confined space entry permit. Employers must establish a confined space entry program which dictates how entry procedures will be used. This program should include:

The use of confined space entry permits which are prepared by competent persons as they evaluate the space and canceled when work is completed or an unauthorized condition exists in the space.
Requirements for evaluating the space prior to entry.
Methods for preventing unauthorized access.
Identify the duties of competent persons, entry attendants, and entrants.
Implement procedures that entry attendants must follow during confined space entries.
Establish procedures for summoning emergency services and rescue teams.
The employer must review the program and amend it when a situation arises that indicates the program may not be adequately protecting employees.

Confined Space entry permits must include:

Name of the space to be entered, authorized entrants, attendants, and supervisors
Purpose of entry / job task
Authorized date and duration of entry
Means of detecting hazardous atmospheres and atmospheric testing results
Name and signature of the supervisor authorizing the entry
Known hazards in the space and mitigation measures to be used
Acceptable entry conditions
Name and telephone number of rescue and emergency services and how they will be contacted
Communication procedures to be used during entry
Special equipment required including PPE
Any miscellaneous information needed to ensure employee safety
Additional permits required, such as hot work or excavation permits, that are relevant to the task at hand,

Roles for Confined Space Entry

Three roles exist for confined space entries:

Authorized Entrant – The individual who will enter the permit space.

Entry Attendant – The individual stationed outside the space who monitors conditions within the space, prevents unauthorized entry, and summons emergency services or initiates rescue procedures if necessary.

Entry Supervisor – A qualified person responsible for overseeing entry operations.

Reclassifying Permit Spaces

A permit space that contains only physical hazards may be reclassified as a non-permit space if (1) the physical hazards are eliminated or isolated without entering the space; or (2) the physical hazards are eliminated or isolated by entering the space using permit space procedures. Physical hazards include all hazards that are not atmospheric hazards, including: explosives (other than explosive atmospheres); mechanical, electrical, hydraulic and pneumatic energy; radiation; temperature extremes; engulfment; noise; inwardly converging surfaces; and chemicals that can cause death or serious physical harm through skin or eye contact (rather than through inhalation).

Additional ASP Exam Study Resources

OSHA’s Confined Space Homepage

OSHA’s Permit-Required Confined Spaces Publication