Vol IO, pp 147-I
Printed in the USA . Copyright
@ 1992 Pergamon
MOLTEN WIETALBURN OF THE FOOT: A PREVENTABLE INJURY Harvey J. Himel, MD, J. Michael Syptak, BA, Kendall C. Jones, Jr., Michael A. Towler, MSME, and Richard F. Edlich, MD, PhD
Department of Plastic Surgery, University of Virginia, Charlottesville, Virginia Reprint Address: Richard F. Edlich, MD, PhD, Department of Plastic Surgery, University of Virginia School of Medicine, Box 332, Charlottesville, VA 22908
metal burns through the leather of the protective footwear. Because considerable heat is dissipated as the molten metal burns through the leather, the underlying burn injury is usually superficial (1). The final mechanism of molten metal burn injury causes a crippling disability. The molten metal is spilled onto the shoe gaining access via the top of the boot or seeping around the tongue (1). The collection of molten metal in the shoe prolongs thermal contact insuring the development of deep partial-thickness or full-thickness burn injuries. It is the purpose of this case report to describe the most severe case of molten metal burn injury. Molten iron passed through the worker’s shoe laces onto the tongue, seeping into his boot. The molten metal encircled the distal end of his foot causing a severe burn injury that required amputation of four toes. This severe occupational hazard could have been prevented by ankle and foot spats and quick release boots with metatarsal guards.
0 Abstract-Molten metal burns of the feet remain a common injury to foundry workers. A case is reported of a foundry worker who sustained circumferential molten metal burns of the distal foot and toes necessitating amputation of four toes. This severe injury could easily have been prevented by the use of protective footwear and spats. 0 Keywords- molten metal; burn; foot; prevention
Molten metal burns remain a frequent industrial injury among workers in foundries (l-5). A variety of molten metals have been involved, including iron, steel, manganese, brass, aluminum, and zinc. The molt temperatures range from 760°C to 14OOOC(5). The magnitude of burn injury depends on the mechanism of injury, which affects duration of heat contact (1). In general, molten metal burns occur in three ways. In one circumstance, the spilled metal contacts the proximal portion of an unprotected extremity. The molten metal (for example, aluminum and brass alloys) tends not to adhere to the skin, but will run downward along the extremity without sufficient contact time to create deep burns (3). In contrast, molten metal (for example zinc) that adheres to the skin will cause a superficial burn injury. The second method of injury occurs when the molten
The patient is a 116-kg, 28-year-old white male who inadvertently spilled molten iron on his right steeltipped safety boot at the foundry. The molten metal passed through his shoe laces onto the tongue of the boot and then seeped into the boot. Even though the molten metal had burned through his shoe laces, he was not able to remove his work boot for 5 minutes. By cutting through the side of his boot, his co-workers removed it, but left his sock on his right foot.
This research was supported by a generous gift from the Texaco Philanthropic Foundation, White Plains, New York.
26 July 1991; ACCEPTED:
12 August 1991
$5.00 + .OO
H. J. Himel, J. M. Syptak, K. C. Jones, Jr., M. A. Towler, R. F. Edlich
His foot was immediately soaked in cool water for 30 minutes. The rescue squad then transported the patient to the nearest community hospital. Upon admission to the emergency department, he was alert, oriented, and had stable normal vital signs (blood-pressure 119/77 torr, pulse 63 beats/min). After his sock was removed, physical examination revealed a circumferential full-thickness burn of the distal foot involving all five toes. He was then transported by ambulance to the regional burn center. When he arrived, the skin surrounding each toe had no sensation. In addition, there was evidence of impaired joint proprioception. The absence of digital blood flow in each toe was confirmed by the Doppler flowmeter and was consistent with our clinical impression of vascular insufficiency in the toes of his right foot. He was immediately taken to the operating room for digital escharotomies of each toe. His foot was cleansed with poloxymer-188 soaked in fine pore-cell sized sponges. The escharotomies extended the entire length of each toe and were positioned above the flexor skin creases (Figure 1). Subcutaneously, on the volar aspect of each toe, the thin band of fascia extending from the volar edge of the phalanges to the skin was divided, providing decompression of the volar compartment of each toe. Perfusion was restored to each toe as evidenced by bleeding from the cut dermis and the presence of digital blood flow detected by the Doppler flowmeter. Nitrofurazone ointment was employed as the topical antimicrobial agent to prevent the development of burn wound sepsis. Two separate debridements were undertaken, which included amputation of the middle and distal phalanges of all toes, except the great toe (Figure 2). The granulating burn wound without eschar was finally covered with split-thickness meshed skin grafts. These skin grafts healed without infection. He was discharged with crutches, allowing him to ambulate without bearing weight on his foot. He was able to return to work 2 months after injury.
DISCUSSION It has been 25 years since Pap (1) first described three cases of hot molten metal burns of the feet in foundry workers. All three workers sustained fullthickness burn injuries requiring skin grafts, but one worker ultimately required amputation of the terminal phalanx of one toe. In 1981, Kahn and McGrady-Kahn (2) reported 16 cases of molten metal burns of foundry workers
04 Figul re 1. (a) Full-thickness burn of dorsum of foot. (b) Fullthick :ness burn of sole of foot. Note arrows indicate escharotomy f incisions of toes.
Molten Metal Burn
03 Figure 2. (a) Healed burn wound of dorsum of foot. Note amputation of all toes, except large toes. (b) Healed burn wound of sole of foot.
over a period of 7 years. All of their patients sustained either deep partial-thickness or full-thickness burns. It was interesting to note that only one of the 16 patients was immediately admitted to the hospital, the others being treated as outpatients until debride-
ment and skin grafting was undertaken. The largest series of molten metal burns was described by Boss and Arons (3). They described 20 foundry workers who suffered molten metal burns of foot and ankle over 15 years. All patients required skin grafting. Regan and Moss (4) described a dyecaster who sustained burns to the dominant ring and middle fingers when molten zinc splashed inside his protective glove. A split-thickness skin graft was used to cover the injury 7 days later. Grube, Heimbach, and Engrav (5) described another 10 cases of patients with molten metal injuries of the lower extremities who were subjected to two different treatment protocols after skin grafting. They reported that the compression of skin graft with Unna paste boot shortened hospital stay and permitted early ambulation and more rapid return to work than the conventional noncompressive dressing. The Unna paste technique, originally described by our team of scientists, is applicable for skin burn injuries not involving the underlying bone (6). Our patient experienced the most severe disability due to molten metal burns ever reported in the literature. He sustained full-thickness circumferential burns of his foot requiring amputation of four toes, despite immediate immersion in cold water and subsequent escharotomies. The disastrous consequences of molten metal burn in our patient were due to multiple factors. First, the enormous temperature elevation of molten metal was probably the most significant factor. In experimental studies, Blomgren, Bagge, and Johannson (7) showed that the threshold temperature of 52OC for 20 seconds caused a full-thickness burn injury that was not ameliorated by immediate cooling. The second factor was the prolonged duration of contact with the molten metal. After the molten metal encircled the toes, it took approximately 5 minutes for the co-workers to remove the boot. Consequently the failure of delayed cooling of dermal injury exposed to much higher temperatures was not unexpected. In addition, digital escharotomies of the burned toes could not salvage them. While digital escharotomies did restore blood flow to the circumferential burn digits, it did not have salutary effect on deep full-thickness burn injuries (8). The best treatment of molten metal burn injuries remains prevention. The Occupational Safety and Health Administration specifically recommends that all molten metal workers wear flameproof pants and jackets, aluminum knee-length coats and leggings, hard hats, molders shoes with metatarsal guards, gloves, and sweat bands for perspiration (9,lO). On the basis of our report, we recommend that these
H. J. Himel, J. M. Syptak, K. C. Jones, Jr., M. A. Towler, R. F. Edlich
wear quick release boots (Try-Guard Model T537, Safety Supply America, Carnegie, PA) with metatarsal guards (Figure 3). Foot and ankle (18-cm) spats (No. 374V, Steel Grip, Inc., Danville, IL) should cover the bottom of the trousers and top of the boot, preventing access of molten metal into the top of the boot. If the foundries would comply with these recommendations, molten metal burns of the feet would be a subject of historical interest.
Figure 3. Quick-release shoe with metatarsal guard. Arrows point to ringlets that can be grasped by hand to facilitate shoe removal.
regulations be supplemented by specific protective apparel requirements. The foundry worker must
Molten metal burns are a frequent industrial injury among workers in foundries. This report describes the most severe case of molten metal burn injury. Molten iron passed through the worker’s shoe laces onto the tongue of the shoe, seeping into his boot. The molten metal encircled the distal end of his foot causing severe burn injury that required amputation of four toes. This severe occupational hazard could have been prevented by ankle and foot spats and quick release boots with metatarsal guards.
REFERENCES 1. Pap GS. Hot metal burns of the feet in foundry workers. J Occup Med. 1966;8:537-9. 2. Kahn AM, McGrady-Kahn VL. Molten metal burns. West J Med. 1981;135:78-80. 3. Boss WK, Arons JA. Molten metal safety boot burns: analysis and treatment. J Trauma. 1982;22:884-6. 4. Regan MW, Moss ALH. Circumferential burns to the fingers associated with gold and platinum rings. Burns. 1986;12:360-3. 5. Grube BJ, Heimbach DM, Engrav LH. Molten metal burns to the lower extremity. J Burn Care Rehab. 1987;8:403-5. 6. GoldenGT, Power CG, Skinner JR, Fox JW, Hiebert JM, Edgerton MT, Edlich RF. A technique of lower extremity mesh grafting withearlyambulation. Am J Surg. 1977;133:646.
7. Blomgren I, Bagge U, Johansson BR. Effects of cooling after scald injury to a dorsal skin fold of a mouse. Stand J Plast Reconstr Surg. 1985;19:1-9. 8. Salisbury RE, Taylor JW, Levine NS. Evaluation of digital escharotomy in burned hands. Plast Reconstr Surg. 1976;58: 440-3. 9. US Department of Labor, Bureau of Labor Statistics. Heat Burn Injuries: Bulletin, No. 2358. Washington: US Government Printing Office; 1990. 10. Occupational Safety and Health Administration. OSHA national emphasis for foundries. Washington: US Government Printing Office; 1977:1-Xx1-1,38.