Mecoprop-P

Herbicides

Active substance -> EU Pesticides database: Approved

Pesticides -> Herbicides, Chlorophenoxy

Environmental transformation -> Pesticides (parent, predecessor)

Danger

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P264, P264+P265, P270, P273, P280, P301+P317, P305+P354+P338, P317, P330, P391, and P501 (click each P-code to see the statement)

Danger

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P264+P265, P270, P273, P280, P301+P317, P305+P354+P338, P317, P330, P391, and P501 (click each P-code to see the statement)

Commission Regulation No 844/2012

MCPP-p acid + salts is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

03/70/EC, Dir. 03/70/EC, Reg (EU) 2026/2025, Reg. (EU) 2016/2016, Reg. (EU) 2016/2016, Reg. (EU) 2018/1796, Reg. (EU) 2018/1796, Reg. (EU) 2018/84, Reg. (EU) 2018/84, Reg. (EU) 2019/2094, Reg. (EU) 2019/2094, Reg. (EU) 2021/2068, Reg. (EU) 2021/52, Reg. (EU) 2024/324, Reg. (EU) 2025/787 , Reg. (EU) No 2023/114, Reg. (EU) No 540/2011, Reg. (EU) No 540/2011, Reg. (EU) No 823/2012, Reg. (EU) No 823/2012

REACH registered substance: mecoprop-P (ISO); (R)-2-(4-chloro-2-methylphenoxy)propionic acid (EC: 240-539-0)

Mecoprop-p: HSNO Approval: HSR003313 Approved with controls

Acute Tox. 4 (100%)

Acute toxicity (ingestion) - category 4

Acute Tox. 4

Exposure to large amounts of CDDs causes chloracne, a severe skin disease with acne-like lesions that occur mainly on the face and upper body. CDDs may also cause liver damage and induce long-term alterations in glucose metabolism and subtle changes in hormonal levels. In addition, studies have shown that CDDs may disrupt the endocrine system and weaken the immune system, as well as cause reproductive damage and birth defects, central and peripheral nervous system pathology, thyroid disorders, endometriosis, and diabetes. 2,3,7,8-Tetrachlorodibenzo-p-dioxin is also a known human carcinogen. (L177, L178)

CDDs cause their toxic effects by binding to the aryl hydrocarbon receptor and subsequently altering the trascription of certain genes. The affinity for the Ah receptor depends on the structure of the specific CDD. The change in gene expression may result from the direct interaction of the Ah receptor and its heterodimer-forming partner, the aryl hydrocarbon receptor nuclear translocator, with gene regulatory elements or the initiation of a phosphorylation/dephosphorylation cascade that subsequently activates other transcription factors. The affected genes include several oncogenes, growth factors, receptors, hormones, and drug-metabolizing enzymes. The change in transcription/translation of these genes is believed to be the cause of most of the toxic effects of CDDs. This includes 2,3,7,8-tetrachlorodibenzo-p-dioxin's carcinogenicity is thought to be the result of its ability to alter the capacity of both exogenous and endogenous substances to damage the DNA by inducing CYP1A1- and CYP1A2-dependent drug-metabolizing enzymes. (L177)

1.75

OPP

0.04

OPP

MCPP-p acid + salts

1.75

11700

Children

0.04

200

CDDs are absorbed through oral, inhalation, and dermal routes of exposure. CDDs are carried in the plasma by serum lipids and lipoproteins, distributing mainly to the liver and adipose tissue. CDDs are very slowly metabolized by the microsomal monooxygenase system to polar metabolites that can undergo conjugation with glucuronic acid and glutathione. They may increase the rate of their own metabolism by inducing CDDs induce both phase I and phase II enzymes. The major routes of excretion of CDDs are the bile and the feces, though smaller amounts are excreted in the urine and via lactation. (L177)

Used as a plant growth regulator (herbicide); The R isomer has been identified as the herbicidally active isomer and with advances in chemical synthesis can now be affordably commercially manufactured; This enriched isomeric form is being called Mecoprop-p (MCPP-p) and is replacing the racemic mixture in all formulations being used in the US; [Reference #1]

Dioxins occur as by-products from the manufacture of organochlorides, the bleaching of paper, chlorination by waste and drinking water treatment plants, municipal solid waste and industrial incinerators, and natural sources such as volcanoes and forest fires. (L177, L178)

Information on 8 consumer products that contain Mecoprop-p in the following categories is provided:

Information on 14 consumer products that contain d-Mecoprop in the following categories is provided: