headache. Large amounts act as an anesthetic causing unconsciousness or death. Personnel should not be permitted to work in spaces where hydrocarbon vapor concentrations exceed 500 parts per million by volume, unless they are protected by an air-supplied respirator. It is recommended that personnel be permitted to work only in well-ventilated spaces where the hydrocarbon vapors are at or below the permissible limit. The occurrence of any of the symptoms mentioned, among personnel who are handling gasoline or who are within an area in which gasoline is handled or spilled, should be taken as a warning of the presence of danger- ous amounts of gasoline vapor in the air. All exposed personnel must be sent out of the area until the vapors have been cleared. Recovery from early symptoms is usually prompt after removal to fresh air. Anyone who is overcome should be given first aid at once. Medical attention should be obtained promptly. First aid in- cludes removing gasoline from the skin (if the skin or clothing has been contaminated in a fall or other acci- dent), preventing chilling, and applying artificial respi- ration if breathing has ceased. Tetraethyl lead, which was added to increase the antiknock value of gasoline, is no longer used,  but it could remain impregnated in tanks or piping sys- tems. The lead compound may enter the body through inhalation, by absorption through the skin, and by the mouth. Also, the gasoline vapor itself, when inhaled, may result in sickness. Therefore, take the following precautions: —Avoid contact with liquid gasoline. —Do not inhale gasoline vapors. —Do not enter tanks that have contained gasoline until all traces of gasoline vapors have been eliminated. NOTE for Sediment and sludge impregnated with gasoline may be present at the bottom of the tank. These constitute a serious fire and poison hazard until the tank is thoroughly cleaned. Before you enter the gasoline storage tanks, you  must  obtain  permission  from  the  com- manding officer, and the gas-free engineer must test and certify the tanks are safe for entry. There is danger in entering a tank that has been used the storage of gasoline because of the chance of exposure to the toxic concentration of gasoline vapors in the air and in the sludge, wet or dry, in the bottom of such tanks. No person should be permitted to enter such a tank without special equipment and complete instruc- tions for its use. Gasoline  is  exceedingly  irritating  when  swal- lowed. If gasoline should be swallowed, accepted first aid procedures must be followed and medical attention obtained as soon as possible. Gasoline causes severe burns if it is allowed to remain in contact with the skin, particularly when the contact is maintained under soaked clothing or gloves. Clothing or shoes having gasoline on them should be removed at once. Repeated contact with gasoline re- moves the protective oils from the skin and produces drying, roughness, chapping, and cracking. Skin in- fection may follow this damage to the skin. A severe skin irritation may develop, beginning usually on the hands and perhaps extending to other parts of the body. As soon as possible after contact, gasoline should be removed from the skin, preferably by washing with soap and water. Rags or waste, wet with gasoline, must not be put in a pocket, but must be disposed of at once. Soaked clothing should be kept away from flames or sparks, and should be washed out thoroughly with soap and water as soon as possible. If gasoline comes in contact with the eyes, accepted first aid procedures must be given at once. Jet Fuels Jet fuels may contain more toxic aromatics than gasolines. They should, therefore. be handled with the same health precautions as apply to gasolines. They should not be used for cleaning. The hygienic or health aspects for gasoline, therefore, apply equally well to jet fuels. These include precautions covering particu- larly the inhalation of vapors, skin irritations, and container  hazards. An important step in preventing the buildup of fuel vapors is to operate the ventilation system pro- vided  for  all  spaces  where  fuels  are  handled.  The aviation fuels security watch must monitor the venti- lation  in  these  spaces  when  they  are  not  manned. Vapor buildup due to inoperative ventilation is dan- gerous to both you and your ship. Notify your super- visor  immediately  if  you  discover  the  ventilation system in one of your fuels spaces is not working. The Standard First Aid Training Course, NAV- EDTRA  12081,  should  be  studied  by  all  personnel working with fuels for information on the treatment of those overcome or injured when handling fuels. 3-4