Hypophosphorous Acid

Expected Concentrations

Although hypophosphorous acid may be utilized during the clandestine manufacture of methamphetamine, it is not easily obtained and is not a common method of manufacture.  The use of hypophosphorous acid replaces the need to obtain red phosphorous in a solid form from match books.  Analysis for phosphorous by National Jewish Medical and Research Center did not result in any positive samples during any of their "cooks".  The primary exposure concern regarding hypophosphorous acid is due to the production of phosphine gas during the production process.  The amount produced is dependant upon process temperature and isolation.  Phosphine is covered in the section regarding chemicals produced.

General Health Effects

Hypophosphorous acid is not considered to be an extremely toxic compound but it may have properties similar to phosphoric acid in that it may cause eye irritation, tearing, blinking and burns.  It may irritate mucous membranes and chronic exposure may result in pulmonary problems, bone marrow and liver problems.  There are no current OSHA or NIOSH standards for exposure.

Health Risks to Children

Children with exposures to hypophosphorous acid  are likely to have similar symptoms as do adults.  Children may be more susceptible to pulmonary damage due to a greater lung surface area per body weight and a more rapid breathing rate.(1,2) 

Fetal Health Effects

There are no known human fetal health effects from parental exposure to hypophosphoric acid.


    1. Proctor, N.H., Hughes, J.P.  1978.  Chemical Hazards of the Workplace.  J.B. Lippincott Co.  Philadelphia, PA  533 pp.
    2. Salocks, C. and Kaley, K.B.  Technical Support Document:  Toxicity Clandestine Labs: Methamphetamine.  Vol 1., Number 12. Red Phosphorous.  Cal/EPA.  Office of Environmental Health Hazard Assessment.  Sacramento, CA .  2003.  10 pp.