NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005




Synonyms & Trade Names

p,p'-Dimethoxydiphenyltrichloroethane; DMDT; Methoxy-DDT; 2,2-bis(p-Methoxyphenyl)-1,1,1-trichloroethane; 1,1,1-Trichloro-2,2-bis-(p-methoxyphenyl)ethane
DOT ID & Guide
2761 / 151 (organochlorine pesticide, solid, toxic)


NIOSH REL: Ca See Appendix A
OSHA PEL: TWA 15 mg/m3
Ca [5000 mg/m3] See: 72435
Physical Description
Colorless to light-yellow crystals with a slight, fruity odor. [insecticide]
MW: 345.7
BP: Decomposes
MLT: 171°F
Sol: 0.00001%
VP: Very low
IP: ?

Sp.Gr: 1.41
Fl.P: ?
UEL: ?
LEL: ?

Combustible Solid, but difficult to burn.
Incompatibilities & Reactivities

Measurement Methods
NIOSH S371 (II-4); OSHA PV2038
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Prevent skin contact
Eyes: No recommendation
Wash skin: When contaminated/Daily
Remove: When wet or contaminated
Change: Daily

First Aid
(See procedures)

Skin: Soap wash
Breathing: Fresh air
Swallow: Medical attention immediately
Respirator Recommendations
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(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
(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
Exposure Routes
inhalation, ingestion
In animals: fasciculation, trembling, convulsions; kidney, liver damage; [potential occupational carcinogen]
Target Organs
central nervous system, liver, kidneys

Cancer Site
[in animals: liver & ovarian cancer]
See also: INTRODUCTION   See ICSC CARD: 1306