ARLINGTON FIRE DEPARTMENT
STANDARD OPERATING PROCEDURES
ISSUED: MARCH 2002
SAFETY
TWO IN/TWO OUT
202.06
PURPOSE
To establish procedures that ensure the highest level of fireground safety while conducting interior structural
firefighting in an atmosphere that is Immediately Dangerous to Life and Health (IDLH).
SCOPE
All members of the Arlington Fire Department shall comply with Occupational Safety and Health
Administration (OSHA) regulation 29 CFR 1910.134 (g)(4). This regulation is commonly known as the
Two In/Two-Out rule, requiring two firefighters to be outside for rescue before two firefighters can enter a
structure involved in fire beyond the incipient stage.
DEFINITIONS
Interior Structural Fire Fighting - The physical activity of fire suppression, rescue or both, inside of
buildings or enclosed structures that are involved in a situation beyond the incipient stage (29 CFR
1910.155).
Incipient Stage Fire - A fire which is in the initial or beginning stage and which can be controlled or
extinguished by portable extinguishers, class II standpipe or small hose system without the need for
protective clothing or breathing apparatus.
Immediately Dangerous To Life Or Health (IDLH) - An atmosphere that poses an immediate threat to life,
would cause irreversible adverse health effects or would impair an individual’s ability to escape from a
dangerous atmosphere.
Initial Rapid Intervention Crew (IRIC) - A minimum of two firefighters, fully equipped and trained, on
standby outside the structure to provide assistance or rapid rescue, if needed. One IRIC member must
actively monitor the status of the inside firefighters and not be assigned to any other duties. The second IRIC
member may be assigned to an additional role so long as this individual is able to perform immediate rescue
activities.
Imminent Life-Threatening Situation - A situation in which immediate action is required to prevent the loss
of life or serious injury before the team of four firefighters is assembled (TCFP - Chapter 435.17).
PROCEDURES
Prior to initiating interior structural fire fighting operations, a minimum of four firefighters shall be assembled
on scene. If the first arriving company is staffed with less than four personnel, they should conduct a
comprehensive size-up, protect exposures, and prepare for interior operations prior to the second-due
company’s arrival.
When a minimum of four firefighters is assembled on scene, two firefighters with a radio may begin an
interior attack. The interior attack can only be initiated when the two outside firefighters have donned the
necessary protective gear.
The initial attack crew will consist of at least two firefighters with a radio. While in the IDLH atmosphere the
firefighters must remain in visual or voice (not radio) contact with each other.
1.
Visual means that the firefighters must be close enough to see each other.
2.
Voice means that the firefighters must be close enough to speak to one another without the use of a
radio.
Page 1 of 2
ARLINGTON FIRE DEPARTMENT
STANDARD OPERATING PROCEDURES
ISSUED: MARCH 2002
SAFETY
TWO IN/TWO OUT
202.06
The firefighters located outside the IDLH atmosphere shall be equipped with the appropriate retrieval
equipment where retrieval equipment would contribute to the rescue of the firefighters that have entered the
IDLH atmosphere.
One of the outside firefighters must actively monitor the status of the inside firefighters and not be assigned
other duties. The second outside firefighter may be assigned to an additional role so long as this individual is
able to immediately perform assistance or rescue activities.
The firefighters outside the IDLH atmosphere must remain in communication (including, but not limited to,
radio) with the firefighters in the IDLH atmosphere. Use of a signal line (rope) as a communications
instrument for interior firefighting, is not permitted by the Commission. NOTE - This does not preclude the
use of rescue/search ropes used during structural searches.
EXCEPTIONS
Incipient Stage Fire
Entry may be made while a fire is in the incipient stage. This is defined as a fire in the initial or beginning
stage, which can be controlled by a portable fire extinguisher, class II standpipe, or small hose (no larger than
a red line).
Imminent Life-Threatening Situation
An imminent life-threatening situation exists when immediate action could prevent the loss of life or
serious injury before the team of four firefighters is assembled. Where initial arriving personnel find an
imminent life-threatening situation, deviation from this procedure is permitted within the following parameters:

Command shall notify Dispatch by radio that a rescue is being attempted without an IRIC on scene.
(Example - Engine 4 is on with a one-story frame working residential fire, Engine 4 will be making
entry without an IRIC.)

Dispatch will notify all responding companies that entry is being made without on IRIC on scene.
(Example - Dispatch to all responding companies, Engine 4 is on scene attempting rescue without an
IRIC.)

After completing a search of the structure or rescue of the occupants, firefighters are to withdraw
from the structure until Two-In/Two-Out procedures can be implemented with the arrival of additional
personnel.

All deviations of the Two-In/Two-Out policy shall be documented by the company officer in a Through
Channels letter to the Fire Chief.
Page 2 of 2