Ammonia

Synonyms & Trade Names

Anhydrous ammonia, Aqua ammonia, Aqueous ammonia [Note: Often used in an aqueous solution.]

CAS No.

7664-41-7

RTECS No.

BO0875000

DOT ID & Guide

1005 125(anhydrous)
2672 154(10-35% solution)
2073 125(>35-50% solution)
1005 125(>50% solution)

Formula

NH₃

Conversion

1 ppm = 0.70 mg/m³

IDLH

300 ppm
See: 7664417

Exposure Limits

NIOSH REL

TWA 25 ppm (18 mg/m³) ST 35 ppm (27 mg/m³)

OSHA PEL

TWA 50 ppm (35 mg/m³) See Appendix G

Measurement Methods

NIOSH 3800 , 6015 , 6016;
OSHA ID188
See: NMAM or OSHA Methods

Physical Description

Colorless gas with a pungent, suffocating odor. [Note: Shipped as a liquefied compressed gas. Easily liquefied under pressure.]

Molecular Weight

17.0

Boiling Point

-28°F

Freezing Point

-108°F

Solubility

34%

Vapor Pressure

8.5 atm

Ionization Potential

10.18 eV

Flash Point

NA (Gas)

Upper Explosive Limit

28%

Lower Explosive Limit

15%

Relative Gas Density

0.60

[Note: Although NH₃ does not meet the DOT definition of a Flammable Gas (for labeling purposes), it should be treated as one.]

Incompatibilities & Reactivities

Strong oxidizers, acids, halogens, salts of silver & zinc [Note: Corrosive to copper & galvanized surfaces.]

Exposure Routes

inhalation, ingestion (solution), skin and/or eye contact (solution/liquid)

Symptoms

irritation eyes, nose, throat; dyspnea (breathing difficulty), wheezing, chest pain; pulmonary edema; pink frothy sputum; skin burns, vesiculation; liquid: frostbite

Target Organs

Eyes, skin, respiratory system

Personal Protection/Sanitation

(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated (solution)
Remove:When wet or contaminated (solution)
Change:No recommendation
Provide:Eyewash (>10%), Quick drench (>10%)

First Aid

(See procedures)
Eye:Irrigate immediately (solution/liquid)
Skin:Water flush immediately (solution/liquid)
Breathing:Respiratory support
Swallow:Medical attention immediately (solution)

Respirator Recommendations

NIOSH

Up to 250 ppm:
(APF = 10) Any chemical cartridge respirator with cartridge(s) providing protection against the compound of concern*
(APF = 10) Any supplied-air respirator*

Up to 300 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode*
(APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern*
(APF = 50) Any chemical cartridge respirator with a full facepiece and cartridge(s) providing protection against the compound of concern
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

Ammonia

NIOSH REL

OSHA PEL

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