room or bunker 540 consideration was given to the concentrations of CS in that area. 541 The bunker was a solid concrete room inside the Davidian residence. It had no windows or other access to the outside of the building, but did open into a hallway inside the residence. It appears that there was little opportunity for CS to have been directly sprayed into the bunker and that any CS that was present in the bunker likely drifted into that room after it was sprayed into one or more of the rooms along the outside of the structure. The subcommittees note, however, that the videotape of the insertion of CS on April 19 indicates that one of the CEV's drove into the structure near the bunker during the fourth phase of the CS insertion. If the door to the bunker had been open at that time, it is possible that CS might have been injected directly into the bunker.

Based on this possibility the subcommittees attempted to determine, as a worst case scenario, the concentration of CS that would have been present in that room had the CEV emptied the entire contents of one of its CS containers into the bunker. It appears, however, that even in that event the concentration of CS would not have reached lethal levels.

The volume of the bunker room was approximately 44.40 cubic meters. Assuming that an entire cylinder (30 grams) of CS was injected into the room, the concentration at that moment would have been 675.67 mgs/m3.542 As discussed above, the concentration level estimated to be lethal to humans is 61,000 mgs-min/m3. Even had the CEV which was mounted with four containers of CS inserted the contents of all four containers into the bunker, the resulting concentration would have been 2,702.70 mgs/m3.543 Again, this figure is well below the concentration level estimated to be lethal to humans.

Another worse case scenario considered by the subcommittees was the possibility that one of the CEV's might have delivered the entire contents of one of its cylinders of CS agent into one of the smallest rooms of the residence, and that that room was inhabited at the time. It still appears that the concentration of CS would not have reached lethal levels. The smallest rooms in the structure were the women's quarters located on the second floor of the residence. The smallest of these had a total volume of 16.17 cubic meters. Assuming that an entire cylinder of CS had been injected into this room, the concentration at that moment would have been 1855.29 mgs/m3.544 Assuming further that a number of Ferret rounds also happened to be fired into the room at the exact moment that the CS was injected by the CEV (assume an impossible event such as 20 rounds entering the room at the same instant), the concentration at that instant would have been 6,431.66 mgs/

540 See Justice Documents at the Appendix for a diagram of the floor plan of the Branch Davidian residence.

541 It should be noted, however, that none of the autopsies of the persons found in the bunker indicate the cause of death was from exposure to CS.

542 Each cylinder of CS contained 30 grams, or 30,000 milligrams, of CS. 30,000 mgs/44.40 m3 = 675.67 mgs/m3.

543 120,000 mgs/44.4 m3 = 2,702.70 mgs/m3.

544 Each cylinder of CS agent contained 30 grams, or 30,000 milligrams. 30,000 mgs/16.17 m3

m3.545 Again, these figures fall far below the concentrations estimated to be lethal to humans.

While concluding that it is unlikely that the CS reached toxic levels, the subcommittees note the level of exposure to CS experienced by an individual Davidian cannot be determined. It is possible that a person near one of the CEV's injecting the CS may have been subject to a level of CS that was high enough to cause death. Additionally, 10 of the autopsies indicate asphyxiation as the cause of death, but do not indicate whether CS or other factors may have lead to this. The subcommittees are unable to conclude that CS did not play a part in the deaths of these persons.

2. LETHALITY OF METHYLENE CHLORIDE USED WITH CS AT WACO

During the gassing operation, each cylinder of the CS riot control agent introduced into the Branch Davidian residence by the CEV's was mixed with approximately 1,070 grams of methylene chloride. This suspension was then dispersed into the structure by carbon dioxide, which almost immediately evaporated, leaving the suspension of CS and methylene chloride. Additionally, each of the Ferret round projectiles contained 33 grams of methylene chloride as the dispersant medium for the CS agent.

The four phases of insertion of CS agent into the Branch Davidian residence were conducted approximately 2 hours apart. During the first and second phases six cylinders of CS agent were inserted into the residence, delivering approximately 6,420 grams of methylene chloride in each phase.546 During the third and fourth insertions only four cylinders of CS agent were inserted, accounting for approximately 4,280 grams of methylene chloride during each insertion. Assuming a worse case scenario of all of the CS insertions in one phase occurring at the same moment and approximately 1/4 of the Ferret round projectiles entering the building at that same time, thus adding an additional 3,300 grams of methylene chloride in each phase,547 the total concentration of methylene chloride delivered into the building during the first and second insertions was 1,924.87 mgs/m3.5 548

A review of the scientific literature concerning CS agent has located no estimates of the concentration of methylene chloride which would prove harmful or lethal to humans. The only estimates which do exist are with respect to mice and rats. For example, the concentration that would prove lethal to 50 percent of a rat population is estimated to be 2,640,000 mgs-min/m3.549 As can be seen from the above figures, therefore, the total concentrations of meth

545 30 grams of CS agent from a CEV plus 74 grams of CS agent from 20 Ferret rounds is a total of 104 grams (30+ (3.7 x 20) = 104), or 104,000 milligrams. 104,000 mgs/16.17 m3 = 6,431.66 mgs/m3.

546 Each cylinder contained 1,070 grams of methelyene chloride. Six cylinders totaled 9,720 grams.

547 Each Ferret round contained 33 grams of methylene chloride. One hundred Ferret rounds thus inserted 3,300 grams of the chemical into the building.

548 In the first two phases the total quantity of methylene chloride delivered was 9,720 grams ((6 x 1,070) + (100 x 33)) or 9,720,000 milligrams. Divided by the cubic footage of the building (5,049.7 m3) the distribution of the substance throughout the building in these phases was 1,924.87 mgs/m3. In the third and fourth two phases the total quantity of methylene chloride delivered was 7,580 grams ((4 x 1,070) + (100 x 33)) or 7,580,000 milligrams. Divided by the cubic footage of the building (5,049.7 m3) the distribution of the substance throughout the building in these phases was 1,501.08 mgs/m3.

549 See generally Mallinckrodt, Inc., Material Data Safety Sheet 2 (1989); Dow Chemical, Inc.,

ylene chloride at the Davidian residence on that day were less than the concentrations that would prove lethal to even rats.550 It appears, therefore, that the methylene chloride used with the CS agent could not have caused the death of any of the Davidians.

As in the case with CS, the subcommittees considered the possibility that some methylene chloride was concentrated in certain areas of the residence rather than being evenly distributed throughout the entire structure. Because the largest group of bodies recovered after the fire was found in the area of the residence commonly known as the gun room or bunker, consideration was given to the concentrations of methylene chloride in that area.551 As discussed above, the bunker was a solid concrete room with no windows or other access to the outside of the building, but did open into a hallway inside the residence. Again, it appears that there was little opportunity for the methylene chloride carrying the CS agent to have been directly sprayed into the bunker and that any methylene chloride that was present in the bunker likely drifted into that room after it was sprayed into one or more of the rooms along the outside of the structure. But the subcommittees again note that the videotape of the insertion of CS on April 19 indicates that one of the CEV's drove into the structure near the bunker during the fourth phase of the CS insertion. If the door to the bunker had been open at that time, it is possible that methylene chloride carrying the CS agent might have been injected directly into the bunker.

Based on this possibility the subcommittees attempted to determine, as a worst case scenario, the concentration of methylene chloride that would have been present in that room had the CEV emptied the entire contents of one of its CS containers into the bunker. It appears, however, that even in that event the concentration of CS would not have reached lethal levels.

The volume of the bunker room was approximately 44.40 cubic meters. Assuming that an entire cylinder of CS (with 1,070 grams of methylene chloride as a disbursant) was injected into the room, the concentration at that moment would have been 24,099 mgs/ m3.552 Even if the CEV that was mounted with four cylinders of CS inserted the contents of all four containers into the bunker, the resulting concentration would have been 96,396 mgs/m3.553 Both of these figures are well below the concentrations estimated to be lethal to rats.554

Another worse case scenario considered by the subcommittees was the possibility that one of the CEV's might have delivered the entire contents of one of its cylinders of CS agent into one of the smallest rooms of the residence, and that that room was inhabited at the time. It still appears that the concentration of methylene chloride would not have reached lethal levels. The smallest rooms in the structure were the women's quarters located on the second

550 The total quantities from each of the four insertions of CS agent was only 5,356.74 mgs/ m3. ((2 x 1,924.87) + (2 x 1,501.08) = 5,356.74).

551 It should be noted, however, that none of the autopsies of the persons found in the bunker indicate the cause of death was from exposure to methylene chloride.

552 Each cylinder of CS contained 1,070 grams, or 1,070,000 milligrams, of methylene chloride. 1,070,000 mgs/ 44.40 m3 = 214,099 mgs/m3.

553 4,280,000 mgs/ 44.40 m3 = 96,396 mgs/m3.

554 As stated, there are no studies estimating the lethal concentration levels to humans of ex

floor of the residence. The smallest of these had a total volume of 16.17 cubic meters. Assuming that an entire cylinder of CS had been injected into this room, the concentration of methylene chloride at that moment would have been 66,171.93 mgs/m3.555 Assuming further that a number of Ferret rounds also happened to be fired into the room at the exact moment that the CS was injected by the CEV (assume, for example, an event as unlikely as 20 rounds entering the room at the same instant), the concentration at that instant would have been 106,988 mgs/m3.556 Again, these figures fall far below the concentrations estimated to be lethal to rats.

3. OTHER POSSIBLE EFFECTS OF METHYLENE CHLORIDE USED WITH CS AT WACO

While the subcommittees conclude that the levels of methylene chloride did not reach lethal toxic levels, the subcommittees also considered whether the levels of methylene chloride may have affected the Davidians in other ways. At levels over 1,000 parts per million (ppm) anesthetic effects begin to occur in humans.557 At levels above 2,300 ppm, exposure to methylene chloride may cause dizziness.558

Because methylene chloride evaporates rapidly when released into the air, the subcommittees considered separately the concentrations of methylene chloride during each of the four phases of the CS agent insertion. The levels of methylene chloride were greatest during the first two phases (because one of the CEV's was unable to inject the CS agent/methylene chloride mixture during the third and fourth phase).

During the first and second phases, six cylinders of CS agent were inserted into the residence, delivering approximately 6,420 grams of methylene chloride in each phase.559 Assuming that all of the CS inserted by the CEV's during one phase was inserted at a single moment, and that approximately 4 of the Ferret round projectiles used during the entire operation also entering the building at that same time (thus adding an additional 3,300 grams of methylene chloride in each phase 560), and that the Davidian residence was airtight, the concentration of methylene chloride during each of the first two phases would have been 548 ppm.5 561 At this concentration, studies have shown no observable effects in humans.562

555 Each cylinder of CS agent contained 1,070 grams of methylene chloride, or 1,070,000 milligrams. 1,070,000 mgs/ 16.17 m3 = 66,171 mgs/m3.

556 1,070 grams of methylene chloride from a CEV plus 660 grams of methylene chloride from 20 Ferret rounds is a total of 1,730 grams (1,070 + (33 x 20) = 1,730), or 1,730,000 milligrams. 1,730,000 mgs/ 16.17 m3 = 106,988 mgs/m3.

557 2 G. Clayton & F. Clayton, Patty's Industrial Hygiene and Toxicology 3449-3455 (1981); R. Stewart et al., Methylene Chloride: Development of a Biological Standard for Industrial Workers by Breath Analysis (1974).

558 Id.

559 Each cylinder contained 1,070 grams of methylene chloride. Six cylinders totaled 9,720 grams.

560 Each Ferret round contained 33 grams of methylene chloride. One hundred Ferret rounds thus inserted 3,300 grams of the chemical into the building.

561 The molecular weight of methylene chloride gas is 85. One mole of methylene chloride gas is 24.2 liters. 9,720g MC/ 85 = 114 moles. 114 moles x 24.2 liters/mole = 2758 liters of MC. There was 5,049,700 liters of volume in the Davidian residence (5.049.7 m3 x 1000 liters/m3 = 5,049,700). Thus 2767.34/ 5,049,700 x 106 = 548 ppm.

562 U.S. Department of Commerce, Agency for Toxic Substances and Disease Registry, Toxi

In considering the possibility that some methylene chloride was concentrated in certain areas of the residence, rather than being evenly distributed throughout the entire structure, the subcommittees found that it was possible that the levels of methylene chloride reached concentrations that might have caused levels that produced anesthetic effects in humans.

Again, the subcommittees considered the possible concentration in the bunker, as the largest group of bodies recovered after the fire was found there. The volume of the bunker room was approximately 44.40 cubic meters. Assuming that an entire cylinder of CS (with 1,070 grams of methylene chloride as a disbursant) was injected into the room, the concentration at that moment would have been 6,861 ppm.563 This concentration was sufficient to induce dizziness and other anesthetic effects in humans.

As stated, however, the evidence is not determinative as to whether one of the CEV's did, in fact, insert CS directly into the bunker. Additionally, it is unknown if the bunker door was open or closed, a factor that would have significantly affected the concentration levels inside the room. Finally, the air circulation inside the building would have affected the levels of methylene chloride present at any one time. The subcommittees conclude, however, that it is possible that the levels of methylene chloride in the bunker were such that the chemical impaired the Davidians' ability to escape the room. Additionally, the possibility cannot be dismissed that other Davidians, in other areas of the residence, might have been similarly adversely affected if they were directly exposed to an insertion of an entire cylinder of the CS agent/methylene chloride mixture. Thus, the levels of methylene chloride that were present in the Davidian residence as a result of the use of the CS riot control agent might have impaired the ability of some of the Davidians to be able to leave the residence had they otherwise wished to do

So.

G. ANALYSIS OF THE ATTORNEY GENERAL'S DECISION TO END THE STANDOFF ON APRIL 19, 1993

1. THE DECISION NOT TO STORM THE RESIDENCE

The subcommittees received testimony concerning the FBI's decision not to storm the residence in order to end the standoff. Additionally, the Justice Department Report on these events also discusses the factors that went into this decision. According to that report, FBI tactical experts believed that there was a substantial likelihood of significant casualties to FBI agents if a frontal assault on the residence was attempted. The FBI believed that the Davidians had fortified the residence and were ready to offer resistance equal to or perhaps even greater than that they had showed during the failed February 28 assault on the residence by the ATF. The FBI was also concerned about the possibility of suicide by the Davidians in the event of such an assault.564

563 1,070 g MC/ 85 = 12.59 moles. 12.59 moles x 24.2 liters/mole = 304.63 liters of MC. There was 44,400 liters of volume in the bunker (44.40 m3 x 1000 liters/m3 = 44,400). Thus 304.63/ 44,400 x 106 = 6,861 ppm.