Pyrophoric Materials

Chapter 41 establishes requirements for the safe storage and use of pyrophoric materials, including specific provisions for compressed gases and references to other hazardous material chapters.

4101 — General

4101.1 Scope. The storage and use of pyrophoric materials shall be in accordance with this chapter. Compressed gases shall also comply with Chapter 30.

4101.2 Permits. Permits shall be required as set forth in Section 105.6.

4102 — Definitions

4102.1 Definition. The following word and term shall, for the purposes of this chapter and as used elsewhere in this code, have the meaning shown herein.

PYROPHORIC. A chemical with an autoignition temperature in air, at or below a temperature of 130° P (54°C).

4103 — General Requirements

4103.1 Quantities not exceeding the maximum allowable quantity per control area. The storage and use of pyrophoric materials in amounts not exceeding the maximum allowable quantity per control area indicated in Section 2703.1 shall be in accordance with Sections 2701,2703,4101 and 4103.

4103.1.1 Emergency shutoff. Compressed gas systems conveying pyrophoric gases shall be provided with approved manual or automatic emergency shutoff valves that can be activated at each point ofuse and at each source. 4103.1.1.1 Shutoff at source. An automatic emergency shutoff valve shall be installed on supply piping at the cylinder or bulk source. The shutoff valve shall be operated by a remotely located manually activated shutdown control located not less than 15 feet (4572 mm) from the source of supply. Manual or automatic cylinder valves are allowed to be used as the required emergency shutoff valve when the source of supply is limited to unmanifolded cylinder sources. 4103.1.1.2 Shutoff at point of use. A manual or automatic emergency shutoff valve shall be installed on the supply piping at the point of use or at a point where the equipment using the gas is connected to the supply system.

4103.1.1 Emergency shutoff. Compressed gas systems conveying pyrophoric gases shall be provided with approved manual or automatic emergency shutoff valves that can be activated at each point ofuse and at each source.

4103.1.1.1 Shutoff at source. An automatic emergency shutoff valve shall be installed on supply piping at the cylinder or bulk source. The shutoff valve shall be operated by a remotely located manually activated shutdown control located not less than 15 feet (4572 mm) from the source of supply. Manual or automatic cylinder valves are allowed to be used as the required emergency shutoff valve when the source of supply is limited to unmanifolded cylinder sources. 4103.1.1.2 Shutoff at point of use. A manual or automatic emergency shutoff valve shall be installed on the supply piping at the point of use or at a point where the equipment using the gas is connected to the supply system.

4103.1.1.1 Shutoff at source. An automatic emergency shutoff valve shall be installed on supply piping at the cylinder or bulk source. The shutoff valve shall be operated by a remotely located manually activated shutdown control located not less than 15 feet (4572 mm) from the source of supply. Manual or automatic cylinder valves are allowed to be used as the required emergency shutoff valve when the source of supply is limited to unmanifolded cylinder sources.

4103.1.1.2 Shutoff at point of use. A manual or automatic emergency shutoff valve shall be installed on the supply piping at the point of use or at a point where the equipment using the gas is connected to the supply system.

4103.2 Quantities exceeding the maximum allowable quantity per control area. The storage and use of pyrophoric materials in amounts exceeding the maximum allowable quantity per control area indicated in Section 2703.1 shall be in accordance with Chapter 27 and this chapter.

Worked example

Scenario: A university chemistry lab intends to store and use 50 milliliters of a liquid pyrophoric reagent, which is below the maximum allowable quantity (MAQ) per control area.

Explanation: Even though the quantity is below the MAQ, the lab must still comply with the general requirements for hazardous materials (Sections 2701, 2703), the general scope for pyrophoric materials (Section 4101), and the specific general requirements of Section 4103, ensuring appropriate safety measures are in place.

4104 — Storage

4104.1 Indoor storage. Indoor storage of pyrophoric materials in amounts exceeding the maximum allowable quantityper control area indicated in Table 2703.1.1 (1), shall be in accordance with Sections 2701, 2703 and 2704 and this chapter.

The storage ofsilane gas, and gas mixtures with a silane concentration of 1.37 percent or more by volume, shall be in accordance with CGA G-13.

4104.1.1 Liquid-tight floor. In addition to the requirements of Section 2704.12, floors of storage areas containing pyrophoric liquids shall be of liquid-tight construction. 4104.1.2 Pyrophoric solids and liquids. Storage of pyrophoric solids and liquids shall be limited to a maximum area of 100 square feet (9.3 m2) per pile. Storage shall not exceed 5 feet (1524 mm) in height. Individual containers shall not be stacked. Aisles between storage piles shall be a minimum of 10 feet (3048 mm) in width. Individual tanks or containers shall not exceed 500 gallons (1893 L) in capacity. 4104.1.3 Pyrophoric gases. Storage of pyrophoric gases shall be in detached buildings where required by Section 2703.8.2. 4104.1.4 Separation from incompatible materials. In addition to the requirements of Section 2703.9.8, indoor storage of pyrophoric materials shall be isolated from incompatible hazardous materials by I-hour fire barriers with openings protected in accordance with the International BUilding Code. Exception: Storage in approved hazardous materials storage cabinets constructed in accordance with Section 2703.8.7.

4104.1.1 Liquid-tight floor. In addition to the requirements of Section 2704.12, floors of storage areas containing pyrophoric liquids shall be of liquid-tight construction.

4104.1.2 Pyrophoric solids and liquids. Storage of pyrophoric solids and liquids shall be limited to a maximum area of 100 square feet (9.3 m2) per pile. Storage shall not exceed 5 feet (1524 mm) in height. Individual containers shall not be stacked.

Aisles between storage piles shall be a minimum of 10 feet (3048 mm) in width.

Individual tanks or containers shall not exceed 500 gallons (1893 L) in capacity.

4104.1.3 Pyrophoric gases. Storage of pyrophoric gases shall be in detached buildings where required by Section 2703.8.2.

4104.1.4 Separation from incompatible materials. In addition to the requirements of Section 2703.9.8, indoor storage of pyrophoric materials shall be isolated from incompatible hazardous materials by I-hour fire barriers with openings protected in accordance with the International BUilding Code.

Exception: Storage in approved hazardous materials storage cabinets constructed in accordance with Section 2703.8.7.

4104.2 Outdoor storage. Outdoor storage of pyrophoric materials in amounts exceeding the maximum allowable quantity per control area indicated in Table 2703.1.1 (3) shall be in accordance with Sections 2701, 2703 and 2704 and this chapter.

The storage ofsilane gas, and gas mixtures with a silane concentration of 1.37 percent or more by volume, shall be in accordance with CGA G-13.

4104.2.1 Distance from storage to exposures. The separation of pyrophoric solids, liquids and gases from buildings, lot lines, public streets, public alleys, public ways or means ofegress shall be in accordance with the following: Solids and liquids. Two times the separation required by Chapter 34 for Class IB flammable liquids. Gases. The location and maximum amount of pyrophoric gas per storage area shall be in accordance with Table 4104.2.1. 4104.2.2 Weather protection. When overhead construction is provided for sheltering outdoor storage areas of pyrophoric materials, the storage areas shall be provided with approved automatic fire-extinguishing system protection.

4104.2.1 Distance from storage to exposures. The separation of pyrophoric solids, liquids and gases from buildings, lot lines, public streets, public alleys, public ways or means ofegress shall be in accordance with the following:

Solids and liquids. Two times the separation required by Chapter 34 for Class IB flammable liquids.
Gases. The location and maximum amount of pyrophoric gas per storage area shall be in accordance with Table 4104.2.1.

4104.2.2 Weather protection. When overhead construction is provided for sheltering outdoor storage areas of pyrophoric materials, the storage areas shall be provided with approved automatic fire-extinguishing system protection.

Worked example

Scenario: A specialty chemical manufacturer plans to store 5 gallons of a pyrophoric liquid, which exceeds the maximum allowable quantity (MAQ) for indoor storage as listed in Table 2703.1.1(1).

Explanation: For this quantity, the storage facility must adhere to general hazardous material requirements (Section 2701), specific hazardous material storage provisions (Sections 2703, 2704), and all applicable details within Chapter 41 to ensure the safe indoor storage of the pyrophoric material.

4105 — Use

4105.1 General. The use of pyrophoric materials in amounts exceeding the maximum allowable quantity per control area indicated in Table 2703.1.1(1) or 2703.1.1(3) shall be in accordance with Sections 2701, 2703, 2705 and this chapter.

4105.2 Weather protection. When overhead construction is provided for sheltering of outdoor use areas of pyrophoric materials, the use areas shall be provided with approved automatic fire-extinguishing system protection.

4105.3 Silane gas. The use ofsilane gas, and gas mixtures with a silane concentration of 1.37 percent or more by volume, shall be in accordance with eGA G-13.

A table appears here in the adopted code. Refer to the official source for the full table.

The minimum required distances shall be reduced to 5 feet when protective structures having a minimum fire resistance of 2 hours interrupt the line of sight between the container and the exposure. The protective structure shall be at least 5 feet from the exposure. The configuration of the protective structure shall allow natural ventilation to prevent the accumulation of hazardous gas concentrations.

Worked example

Scenario: A semiconductor fabrication plant uses a 20-pound cylinder of a pyrophoric gas in a process, exceeding the maximum allowable quantity (MAQ) for use per control area from Table 2703.1.1(3).

Explanation: The use of this quantity of pyrophoric material requires compliance with the general hazardous material requirements (Sections 2701, 2703), specific hazardous material use provisions (Section 2705), and all relevant sections of Chapter 41 to manage the risks associated with its application.

Frequently asked questions

What are pyrophoric materials?

Pyrophoric materials are substances that spontaneously ignite in air at or below 130°F (54.4°C) without an external ignition source.

Where can I find the maximum allowable quantities (MAQ) for pyrophoric materials?

The maximum allowable quantities per control area for pyrophoric materials are specified in Section 2703.1 and referenced in Table 2703.1.1(1) or 2703.1.1(3) of the code.

Are there additional requirements for compressed pyrophoric gases?

Yes, in addition to this chapter, the storage and use of compressed pyrophoric gases must also comply with the requirements of Chapter 30.