MCPP
Full Profile
General Information
2-(2-Methyl-4-chlorophenoxy) propanoic acid (MCPP) is a colourless or white to tan crystalline powder that is soluble in water.[2] MCPP is a member of the chlorophenoxy herbicide group, which also includes MCPA and 2,4-D, among others.[2] It may also be referred to by its trade names, most notably Mecoprop.[3] There are numerous other synonyms and product names; see HSDB for more information.[2]
Chlorophenoxy herbicides, which include MCPP, have been classified by IARC as Group 2B, possibly carcinogenic to humans, on the basis of limited evidence in human and insufficient evidence in experimental animals.[4] While the epidemiological studies reviewed by IARC suggested associations between exposure to the chlorophenoxy herbicides and non-Hodgkin’s lymphoma (NHL) as well as soft-tissue sarcoma, the studies had several limitations and results were inconsistent.[4]
Other health effects of acute exposure to MCPP include fever, respiratory problems and kidney damage.[5] It is not known whether MCPP exposure has reproductive health effects in humans.[5,6]
MCPP has been ranked by CAREX Canada as Group A (immediate high priority) for both occupational and environmental settings. Prioritization was based on the carcinogenicity and other toxic properties of the substance, the prevalence of exposure in Canada, and the feasibility of assessing exposure.
Regulations and Guidelines
No occupational exposure limits for MCPP in Canada or any other international bodies were located.
Canadian Environmental Guidelines
| Jurisdiction | Limit | Year |
|---|---|---|
| WHO Drinking Water Guideline | 10 µg/L | 2003[5] |
| Maximum Residue Limit for All Foods | 0.1 ppm* | 2008[9] |
Canadian Agencies/Organizations
MCPP was not included in the Canadian government chemical listings reviewed.[10,11]
Main Uses
MCPP has been produced since the 1950s for agricultural and defoliant purposes. MCPP production and use in many countries is now decreasing.[6] MCPP is a general use, selective phenoxy herbicide.[3] It works slowly and is absorbed by plant leaves where it affects growth and enzyme activity.[3]
MCPP is available as a liquid concentrate or granules and can be sprayed on fertilizer pellets.[3] It is used on ornamental plants and sports turf, for forest site preparation, and on drainage ditch banks for selective control of surface broadleaf weeds such as clovers, chickweed, ivy, plantain and others.[3] MCPP can also be used in agriculture on wheat, barley, oats, rye, and corn.[12]
Canadian Production and Trade
Although Canada engages in international trade of herbicides, specific formulations are not listed in TradeMap.[17]
Occupational Exposures
Inhalation and dermal absorption are the most important routes of occupational exposure.[6]
Occupational exposure can occur during production, formulation, application and disposal of MCPP.[6] High level exposures in the workplace can occur as a result of accidents, such as spills.[6] Particular tasks where exposure to MCPP may occur include ground spraying and manual application of herbicides containing MCPP, and the handling of raw materials, intermediates, and finished products during pesticide manufacture, and also during waste processing.[6]
Limited research exists on occupational exposure to MCPP specifically, even among farm workers. The majority of occupational research considers total phenoxy herbicide exposure, or has singled only out exposure to 2,4-D and/or MCPA specifically.
Environmental Exposures
Sources of environmental exposure include contaminated water, food and air and are a consequence of direct application of chlorophenoxy herbicides to agricultural and non-agricultural areas.[5] The half-life of MCPP in soil is approximately 3 weeks; the half-life in water is not available.[18]
In 1998, pesticide residue testing in two Toronto watersheds was undertaken. MCPP was the most commonly detected pesticide in water samples.[18] In the air, MCPP can be transported in droplet, vapour or powder form during and after its application.[5] MCPP may also be present in food from crop application, but concentrations are generally low.[5]
Release of MCPP is not reportable to the National Pollutant Release Inventory (NPRI).[19] A search of a household product database yielded the following results on current potential for exposure to MCPP in Canada:
US Household Products Database
| US Household Products 2010[16] | ||
|---|---|---|
| Search Term | Quantity | Product Type |
| ’MCPP’ | 8 | Weed killers |
Sources
- Wikimedia Commons Picture, ±MCPP
- Hazardous Substances Database (search term: MCPP)
- EXTOXNET Extension Toxicology Network, Pesticide Information Profiles: Mecoprop (1995)
- IARC monograph summary, Supplement 7 (1987) (PDF)
- WHO, Chlorophenoxy Herbicides (excluding 2,4-D and MCPA) in Drinking Water (2003) (PDF)
- IARC monograph summary, Volume 41 (1986) (PDF)
- Health Canada (2010) Guidelines for Canadian Drinking Water
- Exposure Guidelines for Residential Indoor Air Quality (1987) (PDF)
- Food and Drug Regulation (Section 15: Adulteration of Food regulations), Government of Canada (2008)
- Health Canada’s Prioritization of the DSL (2006)
- CEPA List of Toxic Substances
- Assessment of the Economic and Related Benefits to Canada of Phenoxy Herbicides. Prepared for: Industry Research Task Forces for Phenoxy Herbicides. Prepared by: RIAS Inc. Toronto and Ottawa, Canada (2006) (PDF)
- BC Ministry of the Environment, Survey of Pesticide Use in BC (2003) (PDF)
- Struger J, Fletcher T, Martos P, Ripley B, Gris G. Pesticide Concentrations in the Don and Humber River Watersheds (1998-2000). December 2002.
- Ontario Ministry of Agriculture and Food, Survey of Pesticide Use in Ontario, 2003 (2004)
- Household Products Database (US)
- TradeMap (Free subscription required)
- Basrur, SV. Pesticide Use and Effect on the Environment. Toronto Staff Report Prepared for Ontario Board of Health. March 18, 2003. (PDF)
- The National Pollutant Release Inventory
