Page 568 - 2018_IFC

APPENDIX E

2. Bases (alkalis): hydroxides-ammonium (greater than with the definitions for these materials, exposure data
10 percent), calcium, potassium (greater than 1 per- for periods other than 1 hour must be normalized to 1
cent), sodium (greater than 1 percent); certain car- hour. To classify mixtures of compressed gases that
bonates-potassium. contain one or more toxic or highly toxic components,
the LC of the mixture must be determined. Mixtures
3. Other corrosives: bromine, chlorine, fluorine, 50
iodine, ammonia. that contain only two components are binary mixtures.
Those that contain more than two components are mul-
Note: Corrosives that are oxidizers (for example, nitric ticomponent mixtures. Where two or more hazardous
acid, chlorine, fluorine), compressed gases (for exam- substances (components) having an LC below 2,000
50
ple, ammonia, chlorine, fluorine), or water-reactive (for ppm are present in a mixture, their combined effect,
example, concentrated sulfuric acid, sodium hydroxide) rather than that of the individual substance components,
are physical hazards in addition to being health haz- must be considered. The effects of the hazards present
ards. must be considered as additive, except where there is a
good reason to believe that the principal effects of the
different harmful substances (components) are not
SECTION E103
EVALUATION OF HAZARDS additive.
For binary mixtures where the hazardous compo-
E103.1 Degree of hazard. The degree of hazard present
depends on many variables that should be considered individ- nent is diluted with a nontoxic gas such as an inert gas,
ually and in combination. Some of these variables are as the LC of the mixture is estimated by use of the meth-
50
shown in Sections E103.1.1 through E103.1.5. odology contained in CGA P-20. The hazard zones
specified in CGA P-20 are applicable for DOTn pur-
E103.1.1 Chemical properties of the material. Chemical poses and shall not be used for hazard classification.
properties of the material determine self reactions and
reactions that could occur with other materials. Generally, E103.1.4 Actual use, activity or process involving the
materials within subdivisions of hazard categories will material. The definition of handling, storage and use in
exhibit similar chemical properties. However, materials closed systems refers to materials in packages or contain-
with similar chemical properties could pose very different ers. Dispensing and use in open containers or systems
hazards. Each individual material should be researched to describes situations where a material is exposed to ambi-
determine its hazardous properties and then considered in ent conditions or vapors are liberated to the atmosphere.
relation to other materials that it might contact and the sur- Dispensing and use in open systems, then, are generally
rounding environment. more hazardous situations than handling, storage or use in
closed systems. The actual use or process could include
E103.1.2 Physical properties of the material. Physical heating, electric or other sparks, catalytic or reactive mate-
properties, such as whether a material is a solid, liquid or rials and many other factors that could affect the hazard
gas at ordinary temperatures and pressures, considered and must therefore be thoroughly analyzed.
along with chemical properties will determine requirements
for containment of the material. Specific gravity (weight of E103.1.5 Surrounding conditions. Conditions such as
a liquid compared to water) and vapor density (weight of a other materials or processes in the area, type of construc-
gas compared to air) are both physical properties that are tion of the structure, fire protection features (for example,
important in evaluating the hazards of a material. fire walls, sprinkler systems, alarms), occupancy (use) of
adjoining areas, normal temperatures, exposure to
E103.1.3 Amount and concentration of the material. weather, etc., must be taken into account in evaluating the
The amount of material present and its concentration must hazard.
be considered along with physical and chemical properties
to determine the magnitude of the hazard. Hydrogen per- E103.2 Evaluation questions. The following are sample
oxide, for example, is used as an antiseptic and a hair evaluation questions:
bleach in low concentrations (approximately 8 percent in 1. What is the material? Correct identification is import-
water solution). Over 8 percent, hydrogen peroxide is ant; exact spelling is vital. Checking labels and SDS
classed as an oxidizer and is toxic. Above 90 percent, it is and asking responsible persons should be among the
a Class 4 oxidizer “that can undergo an explosive reaction highest priorities.
when catalyzed or exposed to heat, shock or friction,” a 2. What are the concentration and strength?
definition that, incidentally, places hydrogen peroxide
over 90-percent concentration in the unstable (reactive) 3. What is the physical form of the material? Liquids,
category. Small amounts at high concentrations could gases and finely divided solids have differing require-
present a greater hazard than large amounts at low concen- ments for spill and leak control and containment.
trations.
4. How much material is present? Consider in relation to
E103.1.3.1 Mixtures. Gases—toxic and highly toxic permit amounts, maximum allowable quantity per
gases include those gases that have an LC of 2,000 control area (from Group H occupancy require-
50
parts per million (ppm) or less when rats are exposed ments), amounts that require detached storage and
for a period of 1 hour or less. To maintain consistency overall magnitude of the hazard.

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