837-012-0850 Construction of Fireworks Aerial Shells (1) Shells may be classified and described only in terms of the inside diameter of the mortar in which they can be safely used, such as three inch shells are only for use in three inch mortars); (2) Aerial shells must be constructed so that they fit easily into the appropriate size mortar and so that the lift charge and internal delay fuse are appropriate to propel the shell to a safe altitude before functioning. (3) Shells must be labeled with the type of shell, the shell size and the name of the manufacturer or distributor. (4) The label or wrapper of any type of aerial shell must be conspicuously marked with a number to indicate the shell size (the diameter of the mortar to be used). (5) The label or wrapper of any type of aerial salute must be conspicuously marked with the word "salute"; (6) For aerial shells using quick match fuse to ignite the lift charge, that fuse must be long enough to allow not less than six inches of fuse to protrude from the mortar after the shell has been properly inserted. EXCEPTION: This requirement does not apply when shells are to be fired electrically. (7) In order to allow the individual igniting the aerial shells to safely retreat, the time delay between igniting the tip of the shell's fuse and the firing of the shell may not be less than three seconds or more than six seconds. EXCEPTION: For electrically ignited displays, there is no requirement for a delay period. (8) A safety cap must be installed over the exposed end of the fuse. The safety cap must be of a different color than that of the fuse. The safety cap must be installed in such a manner so the fuse is not damaged; EXCEPTION: For electrically fired displays, there is no requirement for safety caps except there must be no exposed pyrotechnic composition. (9) Single break salute shells may not exceed three inches in diameter or three inches in length (exclusive of the lift charge). The maximum quantity of salute powder in such salutes may not exceed 3 ounces; (10) Storage of fireworks and aerial shells not in mortars: (a) All fireworks must be stored and transported according to the requirements prior to reaching the display site; (b) As soon as the fireworks have been delivered to the display site, they may not be left unattended or allowed to become wet; (c) All fireworks must be inspected when practical after delivery to the site but always prior to the start of loading shells by the operator or a qualified assistant. Any shells having tears, leaks, broken fuses, or showing signs of having been wet must be set aside and must not be fired. After the display, any such shells must either be returned to the wholesaler or destroyed according to the wholesaler's instructions; EXCEPTION: Minor repairs to fuses may be allowed. Also, for electrically ignited displays, attachment of electric matches and other similar tasks may be permitted. (d) Upon delivery to the display site, all shells must be separated according to size and as to whether they are salutes. Until they are loaded into mortars, shells must be stored in covered containers such as ready boxes or corrugated cartons meeting U.S. Department of Transportation requirements for the transportation of fireworks; (e) During performance of an outdoor display, Ready Boxes must be located at a distance of not less than 30 feet upwind from the mortar placements. If the wind should shift during a display, the ready boxes must be re-located to be 30 feet upwind from the discharge site. EXCEPTIONS: (A) When acceptable to the local fire authority, alternate measures may be taken. (B) When there are no shells needing storage during a display, such as for an electrically ignited display, or where all shells are preloaded into their mortars prior to the start of the display, there is no need for ready boxes. (11) Installation of mortars: (a) Prior to placement mortars must be carefully inspected for defects, such as dents, bent ends, damaged interiors, and damaged plugs. Mortars found to be defective must not be used; (b) Mortars must be positioned vertically or so that shells are propelled away from spectators and over a fallout area. Under no circumstances may mortars be angled toward the spectator viewing areas; NOTE: It is generally believed that when manually firing aerial fireworks, mortars should be angled 2 to 4 degrees. (c) Mortars must be buried to a depth of a minimum of 2/3 of their length, either in the ground or in aboveground troughs or drums; EXCEPTION: Securely positioned mortar racks may be used for the firing of single break shells not exceeding six inches in diameter. (d) Refer to NFPA 1123, Table A.4.3.8 (a) and (b) for minimum inside mortar length requirements. (e) Under conditions when paper mortars may be damaged by placement in damp ground, paper mortars must be placed inside a moisture-resistant bag prior to placement in damp ground; (f) Whenever there is the likelihood of ground water leaking into the mortar, the mortar must be placed inside a water-resistant bag prior to placement in the ground; (g) Weather-resistant coverings must be placed over the mouth of mortars whenever there is imminent danger of water collecting in the mortars; (h) In soft ground, when there is significant danger of the mortars being driven further into the ground when they are fired, sufficient added support must be placed beneath the mortars; EXCEPTION: When a mortar is only to be used once, such as for an electrically fired display, added support is optional. (i) Mortars that are buried in the ground, in troughs, or in drums must be separated from adjacent mortars by a distance at least equal to the diameter of the mortar. Mortars in troughs or drums must be positioned to afford the maximum protection to the operator; EXCEPTION: The requirements do not apply when electrical firing is used. (j) If troughs and drums are used, they must be filled with sand or soft dirt; in no case may stones or other possible dangerous debris be used; (k) Whenever more than three shells are to be chain fused, such as for sequential firing, additional measures are required to prevent adjacent mortars from being repositioned in the event a shell detonates in a mortar, causing the mortar to burst. For buried mortars, this must be accomplished by placing the mortars with a minimum separation of four times their diameter. For mortars in racks, this must be accomplished by using mortar racks that have sufficient strength to successfully withstand such a failure; EXCEPTIONS: (A) When there is doubt concerning the strength of racks holding chain fused mortars, the separation distances for those racks from spectator or parking areas must be twice those listed in Table 1. (B) When the separation distance is two times that required in Table 1, buried mortars must be separated from each other by a minimum of one times the internal diameter of the largest mortar in the sequence. (l) When mortars are to be reloaded during a display, mortars of various sizes may not be intermixed. Mortars of the same size must be placed in groups, and the groups must be separated from each other; (m) When operators or assistants are to be in the immediate area of the mortars during a display, sandbags or other suitable protection must be placed around the mortars up to the approximate level of the mouth of the mortar in each direction where operators or assistants could be located; (n) Mortars must be inspected before the first shells are loaded to be certain that no water or debris has accumulated in the bottom of the mortar; (o) Mortars must be of sufficient strength and durability to safely fire the aerial shells to be used; (p) Cast iron mortars may not be used; (q) Metal mortars may be either seamed or seamless; however, seamed mortars must be placed so the seam is facing either right or left as one faces the line of mortars; (r) Mortars must be of sufficient length to cause aerial shells to be propelled to safe heights; (s) A cleaning tool must be provided for the cleaning of debris from mortars as necessary; EXCEPTION: When mortars are not to be reloaded during a display, there is no requirement for a cleaning tool. (t) Numerals indicating the inside diameter of the mortar may be conspicuously painted or otherwise marked near the top of all mortars. (12) When more than one operator or assistant will be igniting the aerial shells for a display, it is preferred the line of mortars be separated in some manner and that only one operator or assistant light shells in each designated area. (13) Electrical firing unit: (a) The purpose of this section is to provide guidance for the design of electrical firing units to be used when it is decided to electrically fire displays; (b) At no point may electrical contact be allowed to occur between any wiring associated with the electrical firing unit and any metal object in contact with the ground; (c) If the electrical firing unit is powered from AC power lines, some form of line isolation must be employed such as a line isolation transformer; (d) The electrical firing unit must include a key-operated switch or other similar device that greatly reduces the possibility that unauthorized or unintentional firings can occur; EXCEPTION: When the electrical firing unit is very small in size and attached to the wire running to electric matches for the brief duration of the actual firing, there is no requirement for a key-operated switch. (e) Manually activated electrical firing units must be designed such that at least two positive actions must be taken to apply electric current to an electric match. For example, this may be accomplished with two switches in series, both of which must be operated in order to pass current; (f) Computer-activated automatic sequencing type electrical firing units must have some form of "dead-man-switch," such that firings will cease the moment the switch is released; (g) If the electrical firing unit has a built-in-test circuit, the unit must be designed to limit the test current (into a short circuit) to 0.05 ampere or to 20 percent of the no-fire current of the electric match, whichever is less; (h) Multi-testers, such as Volt-O-meters, may not be used for testing unless their maximum current delivering potential has been measured and found to meet the requirements of subsection (g) of this section; (i) When any testing of firing circuits is performed, no person may be present in the immediate area of fireworks that have been attached to the electrical firing unit. [ED. NOTE: Figures referenced are available from the agency.] Statutory/Other Authority: ORS 480.150 Statutes/Other Implemented: ORS 480.110 - 480.165 History: OSFM 2-2025, amend filed 07/15/2025, effective 07/15/2025 OSFM 2-2015, f. 12-22-15, cert. ef. 1-1-16 OSFM 3-2014, f. & cert. ef. 7-1-14 OSFM 3-2004, f. & cert. ef. 1-14-04 OSFM 7-2002, f. & cert. ef. 6-20-02 FM 2-1992, f. & cert. ef. 3-10-92