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Methyl parathion																				Related Pages
Synonyms & Trade Names
			Azophos®, O,O-Dimethyl-O-p-nitrophenylphosphorothioate, Parathion methyl
CAS No.
			298-00-0
	RTECS No.
			TG0175000
	DOT ID & Guide
			2783 152(solid)3018 152(liquid)

Formula(CH3O)2P(S)OC6H4NO2
	Conversion
	IDLH
			N.D.See: IDLH INDEX

Exposure Limits
			NIOSH RELTWA 0.2 mg/m3 [skin]
					OSHA PEL none See Appendix G
	Measurement Methods
			**NIOSH** 5600;**OSHA** PV2112
					
					See: NMAM or OSHA Methods
										
Physical Description
			White to tan, crystalline solid or powder with a pungent, garlic-like odor.
					[pesticide] [Note: The commercial product in xylene is a tan liquid.]													
										
Molecular Weight263.2	
	Boiling Point289°F
	Melting Point99°F
	Solubility(77°F): 0.006%
	Vapor Pressure0.00001 mmHg
	Ionization Potential?											
Specific Gravity1.36	
	Flash Point?
	Upper Explosive Limit?
	Lower Explosive Limit?
Combustible Solid
Incompatibilities & Reactivities
			Strong oxidizers, water
					[Note: Explosive risk when heated above 122°F.]
Exposure Routes
			inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms
			irritation eyes, skin; nausea, vomiting, abdominal cramps, diarrhea, salivation; headache, dizziness, lassitude (weakness, exhaustion); rhinorrhea (discharge of thin nasal mucus), chest tightness; blurred vision, miosis; cardiac irreg; muscle fasciculation; dyspnea (breathing difficulty)
Target Organs
			Eyes, skin, respiratory system, central nervous system, cardiovascular system, blood cholinesterase
										
Personal Protection/Sanitation
			(See protection codes) **Skin:**Prevent skin contact
							**Eyes:**Prevent eye contact
							**Wash skin:**When contaminated/Daily
							**Remove:**When wet or contaminated
							**Change:**Daily
							**Provide:**Eyewash, Quick drench
	First Aid
			(See procedures)**Eye:**Irrigate immediately
							**Skin:**Soap wash immediately
							**Breathing:**Respiratory support
							**Swallow:**Medical attention immediately
Respirator Recommendations
			**NIOSH****Up to 2 mg/m3**: (APF = 10) Any air-purifying half-mask respirator with organic vapor cartridge(s) in combination with an N95, R95, or P95 filter. The following filters may also be used: N99, R99, P99, N100, R100, P100. Click here for information on selection of N, R, or P filters.(APF = 10) Any supplied-air respirator**Up to 5 mg/m3**: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode(APF = 25) Any powered, air-purifying respirator with an organic vapor cartridge in combination with a high-efficiency particulate filter.**Up to 10 mg/m3**: (APF = 50) Any air-purifying full-facepiece respirator equipped with organic vapor cartridge(s) in combination with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister having an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s) in combination with a high-efficiency particulate filter(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode(APF = 50) Any self-contained breathing apparatus with a full facepiece(APF = 50) Any supplied-air respirator with a full facepiece**Up to 200 mg/m3**: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode**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 organic vapor canister having an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.Any appropriate escape-type, self-contained breathing apparatus
				Important additional information about respirator selection
See also
			INTRODUCTION
					  ICSC CARD: 0626

			
							

			Page last reviewed:  October 30, 2019						Content
							source: 	National Institute for Occupational Safety and Health NIOSH Pocket Guide to Chemical Hazards
Introduction
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Appendices
A – NIOSH Potential Occupational Carcinogens
B – Thirteen OSHA-Regulated Carcinogens
C – Supplementary Exposure Limits
D – Substances with No Established RELs
E – OSHA Respirator Requirements for Selected Chemicals
F – Miscellaneous Notes
G – 1989 Air Contaminants Update Project: Exposure Limits NOT in Effect
Type C & CE – Definitions for Type C and Type CE Respirators
Personal Protection and Sanitation Codes
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