Poison Gases

All of these gases are dangerous due to toxicity.  Some are dangerous via other qualities as well (flammable, reactive....). 

REQUIRING WRITTEN APPROVAL ARE -- the white boldface on red background gases.  Use of any quantity of any of these pure gases require Department approval in writing before the work begins, in the Dept of Chemistry and possibly other Depts.  Mixtures containing these gases may also be included under the definition of highly toxic and require approval in writing.  

CGA STANDARD FOR CLASSIFICATION OF TOXIC GAS MIXTURES

• acetyl fluoride ct
• ammonia
• antimony hydride
• arsenic pentafluoride
• arsine
• 2-butene
• boron trichloride
• boron trifluoride
• bromine chloride
• carbon monoxide
• carbonyl chlorofluoride
• carbonyl fluoride
• carbonyl sulfide
• chlorine
• chlorine dioxide
• chlorine monoxide
• chlorine pentafluoride
• chlorine trifluoride
• chlorosilane
• chlorotrifluoroethylene
• coal gas
• cyanogen
• cyanogen chloride
• diborane
• deuterium bromide
• deuterium chloride
• deuterium iodide
• deuterium sulfide
• diazomethane
• dichloroacetylene
• dichlorosilane
• dinitrogen tetroxide
• diphosgene
• ethyl nitrite
• ethylene oxide
• fluorine
• formaldehyde
• germane
• hexaethyl tetraphosphate
• hexafluoroacetone
• 1,3-hexafluorobutadiene
• hexafluoropropene
• hydrogen bromide
• hydrogen chloride
• hydrogen cyanide
• hydrogen fluoride
• hydrogen iodide
• hydrogen selenide
• hydrogen sulfide
• ketene
• methyl bromide
• methyl chloride
• methylchlorosilane
• methyl mercaptan
• mustard gas
• nickel carbonyl
• nitric oxide
  (nitrogen monoxide)
• nitrogen dioxide
• nitrous oxide
• nitrogen trifluoride
• nitrogen trifluoride oxide
• nitrogen trioxide
• nitrosyl chloride
• oil gas
• oxalyl bromide
• oxygen difluoride
• ozone
• perchloryl fluoride
• perfluoroisobutylene
• phosgene
• phosphine
• phosphorus pentafluoride
• selenium hexafluoride
• silicon tetrafluoride
• stibine
• sulfur dioxide
• sulfur pentafluoride
• sulfur tetrafluoride
• sulfuryl fluoride
• tellurium hexafluoride
• trifluoroacetyl fluoride
• trifluorochloroethylene
• bis(trifluoromethyl)peroxide
• tungsten hexafluoride
• vinyl chloride

Background

Poison Gases - see compiled list

Indiana Fire Code (8004.2.3.7) 

Special requirements for highly toxic and toxic compressed gases:

Compressed gas cylinders shall be within gas cabinets, exhausted enclosures, or gas rooms.  Gas cabinets and gas enclosures shall be in accordance with 8003.3.1.3.2 and 8003.3.1.3.3, respectively.  Gas cabinets and gas enclosures shall be internally sprinklered.

8003.3.1.3.2 Gas cabinets must:

1. operate at negative pressure w/re to surrounding area
2. be provided with self-closing limited access pots or noncombustible windows to give access to equipment controls, average velocity at windows/port must be at least 200 fpm, min at any point 150 fpm
3. be connected to an exhaust system
4. be provided with self-closing doors
5. be constructed of not less than 0.097" (12 gauge) steel.

8003.3.1.3.3 Exhausted enclosures must

Basically same as 1 and 2 above.

Definitions:

Toxic:

1. 50 mg/kg < LD50 ≤ 500 mg/kg ( body weight) oral albino rat 200 - 300 g
   OR
2. 200 mg/kg < LD50 ≤ 1000 mg/kg (body weight) continuous 24 h contact
   (or less if death occurs before 24 h) albino rabbits 2 - 3 kg
   OR
3. 200 ppm <  LC50 ≤   2000 ppm  (by volume of gas or vapor), or 2 mg/L <  LC50 ≤  20 mg/L (dust, fume, mist) continuous inhalation for 1 h (or less if death occurs in less than 1 h) to albino rats 200 - 300 g.

Highly Toxic:

1. LD50 of ≤ 50 mg/kg body weight oral albino rat 200 - 300 g
   OR
2. LD50 of ≤ 200 mg/kg body weight  continuous 24 h contact (or less if death occurs before 24 h)     albino rabbits 2 - 3 kg 
   OR
3. LC50 ≤ 200 ppm by volume of gas or vapor, or > 2 mg/L dust/fume/mist continuous inhalation for 1 h (or less if death occurs in less than 1 h) to albino rats 200 - 300 g.

Calculating for Gas Mixtures

Binary mixture = haz component + nonhaz rest, LC_50m = 1/[C_i/LC_50i] 

LC_50m  =  the LC₅₀ of the mixture 
C_i = concentration of component i in decimal percent
LC_50i  = LC₅₀ of component i

MUST NORMALIZE for 1 h exposures via the table given A-VI-A-1 NORMALIZATION FACTOR

Others

Chemistry Dept policy: any person(s) ordering or receiving liquefied or compressed gases on this list will comply with all State and Federal rules pertaining to their use and storage, and will prepare well written SOPs (written standard operating procedures) pertaining to each substance, addressing storage, handling, training, waste disposal, decontamination, and emergency procedures.  No one will receive or handle such materials until after all qppropriate hazard assessments and training have been completed, and all staff working with and near the item(s) have been apprised of the hazards, the means of detecting releases, and the symptoms of exposure. (SOPs must address normal precautions pertaining to health and safety, as well as emergency procedures)

Note: low concentration mixtures of poson gas in inert gas are often not subject to the requirement for a fire-protected ventilated cabinet. 

For table standing alone go to the Poison Gases Table. White type on red background indicates materials fitting the IFC definition of toxic or highly toxic.  LC₅₀ values are rat 1 h inhalation or equivalent as per chart above.  Designations I, II, III, and NR are from the Santa Clara Co. TGO data and are included as a point of interest only.

Table still in progress: 12/10/09

*Reference is to material which is a compressed or liquefied gas or gas mixture obtained in cryo-freezers, cylinders, lecture bottles, or other gas containers.  Does not apply liquid mixtures, e.g. BF₃ etherate, nor aqueous NH₃, HCl, HBr.... 

** IDLH is given as ppm unless otherwise indicated. 

*** Cut-off concentration:  If concentration of toxic gas in any two-component mixture compressed gas cylinder is LESS THAN this amount, the requirement for sprinklered, continuously ventilated cabinet does not apply.

*reference is to compressed and liquefied gases obtained in cryo-freezers, cylinders, lecture bottles, or other gas containers, not to purchased liquid mixtures, e.g. BF₃ etherate, nor aqueous NH₃, HCl, HBr....

** IDLH is given as ppm unless otherwise indicated.

See copy of DOT hazmat table for more info on hazard classes of materials.  (The DOT hazmat table is the source of the designation of certain materials as Poison Gases.)

conc in ppm   = (24.45)(conc in mg/m3)/(gram molecular weight of substance) 

CALCULATIONS and notes

• AsH₃ calculation:  (24.5) (0.3)/82.9 =  0.9 ppm (15 min)

• BF₃ calculation (24.5)(1210)/67.8 = 437.2 ppm (4h) normalize to 1 h ---> 875 ppm

• HF calculation: (24.5)(1100)/20 = 1347 ppm

• GeH₄ calculation (24.5)(1380)/76.6 = 441 except it doesn't say 1 h in the original data....but even if it were 4 h it would still be toxic.....

• COCl2 calculation (24.5)(16)/98.9 = 4 ppm for 75 min inh rat 

• cyanogen chloride calc (24.5)(3.15)/61.47 = 1.26 ppm 

• WF6 calculation (24.5)(1430)/298 = 118 

• CH3Cl calculation (24.5)(5300)/50.5 = 2571 ppm for 4 h rat inh

• NO calculation (24.5) (160)/30.1 = 130 ppm but they do not give the time.

• (24.5)(1068)/30.1 = 869 ppm for 4 h ---- 1739 ppm calc for 1 h LC50

• formaldehyde calculations: (24.5)(480)/30 = 392 (4 h) and multiply by 2 for 1 h ---> 784 ppm

• alternate from 1/2 hr LC50 (24.5)(820)/30 = 468 ppm. Well they don't agree but it's not important, they're close enough.

≥  Alt 242

≤ Alt 243