OSHA PROGRAM DIRECTIVE #100-61 STD 1-5.8 OCT 30, 1978

TO: REGIONAL ADMINISTRATORS/OSHA

Subject: 29 CFR 1910.104(b)(3)(iii), Oxygen; Bulk Oxygen Systems; Distance Between Systems and Exposures; Fire Resistive Structures

1. Purpose

To establish guidelines on citing a violation of 29 CFR 1910.104 (b)(3)(iii).

2. Directives Affected

None.

3. Background

a. Inquiries from various sources have been received regarding OSHA enforcement of 29 CFR 1910.104(b)(3)(iii) which prescribes the following minimum distance between any bulk oxygen storage container and fire resistive structure;

Fire resistive structures twenty-five feet from any structure with fire resistive exterior walls or sprinklered buildings of other construction, but not less than one-half the height of adjacent side wall of the structure.

    b.  These inquiries have noted that the source standard for 29 CFR
         1910.104(b)(3)(iii) was National Fire Protection Association
         (NFPA) No. 566-1965, Standard for the Installation of Bulk Oxygen
         Systems.  This was redesignated at NFPA No. 50, paragraph 5-1-2,
         with the 1971 edition, which states:

Not less than one foot (or other distance to permit system maintenance) from buildings or other than wood frame construction, including fire resistive, heavy timber, noncombustible, and ordinary construction.

OSHA INSTRUCTION STD 1-5.8 OCT 30, 1978

c. 29 CFR 1910.104(b)(3)(xviii) states the twenty-five foot distance requirement between structures with fire-resistive exterior walls or sprinklered buildings of other construction and bulk oxygen storage containers:

(does) not apply where protective structures such as firewalls of adequate height to safe-guard the oxygen storage systems are located between the bulk oxygen storage installation and the exposure. In such cases, the bulk oxygen storage installations may be a minimum distance of 1 foot from the firewall.

d. A"firewall" has been defined by various sources. The National Building Code, 1967 Edition, Section 23.2.A states:

Firewalls shall be of a noncombustible material having a fire resistance rating of not less that 4 hours, and have sufficient standard stability under fire conditions to allow collapse of construction on either side without collapse of the wall.

e. The Fire Protection Handbook, 13th Edition, 1969, NFPA, at page 8-45-50 republished in 1976 defines a firewall as follows:

A firewall may be broadly defined as a wall erected to prevent the spread of fire. To be effective, firewalls must have sufficient fire resistance to withstand the effects of the most severe fire that might be expected to occur in the building and must provide a complete barrier to the spread of fire. Any openings in a firewall must be suitably protected.

f. 29 CFR 1910.106(e)(3)(iii), Flammable and Combustible Liquids; Industrial Plants; Unit Physical Operations; Chemical Processes; establishes that a firewall may have a 2-hour fire resistance rating.

4. Action

a. There appears to be a distinction between structures or walls that are fire resistive (in which case 29 CFR 1910.104(b)(3)(iii) requires a distance of 25 feet between the structure or wall and bulk oxygen storage containers) and those that

OSHA INSTRUCTION STD 1-5.8 OCTOBER 30, 1978

are firewalls ( in which case the exception in 29 CFR 1910.104(b)(xviii) allows a minimum distance of one foot from the container). For the purposes of determining whether a citation is appropriate a fire resistive wall shall be deemed to be one made of fire resistive materials. On the other hand a firewall within the exception provided must be:

(1) at least a wall made of noncombustible material, self-supporting and with a fire resistance rating of not less than 2 hours, and generally constructed in accordance with the definitions provided by local Building Codes and The Fire Protection Handbook provisions cited herein; the wall may be the exterior wall of the structure exposed to the bulk oxygen storage installation;

(2) Any openings in the wall are properly protected:

(3) The wall is of adequate height to safeguard the oxygen storage systems

b. Before citations are issued under 29 CFR 1910.104(b)(3)(iii) for violation of the 25 foot requirement, the compliance officer should assure himself that the wall or structure does not come within the exception provided for in 29 CFR 1910.104(b)(xviii), in which case only the 1 foot distance requirement is applicable.

5. Effective Date

This directive is effective upon receipt and will remain in effect until canceled or superseded.

Richard P. Wilson Deputy Director, Federal Compliance and State Programs

DISTRIBUTION: A-1 E-1 B-2 HEW-1 C-1 NACOSH Regional Directors-1 D-4 & 5 NIOSH-1 Training Institute-4

(Originator:OCCS)