MOCA Profile

INDUSTRIAL CHEMICALS – KNOWN CARCINOGEN (IARC 1)

CAS No. 101-14-4
IARC Monograph Vol. 57, 1993 (Group 2A)
IARC Monograph Vol. 99, 2010 (Group 1)
IARC Monograph Vol. 100F, 2012 (Group 1)

MOCA Profile

General Information

4,4′-Methylenebis (2-chloroaniline) is a synthetic chemical that occurs as tan coloured pellets or flakes.[1] It has a faint amine odour, very low solubility in water, and may explode when heated.[1] It is generally referred to as MOCA, but may also be called bisamine, MBOCA, or MCA.[1] There are numerous other synonyms and product names; see Hazardous Substances Data Bank (HSDB) for more information.[2]

MOCA has been classified by the International Agency for Research on Cancer (IARC) as Group 1, a known human carcinogen.[3] It was first classified as a Group 2A carcinogen in 1987,[4] but was re-classified as Group 1 in 2008 based on strong genotoxic mechanistic evidence.[5] MOCA’s Group 1 classification was reaffirmed under IARC’s review of Group 1 carcinogens in 2012.[6] In experimental animals, MOCA causes liver, bladder, and lung cancer.[3]

Additionally, when MOCA is inhaled or ingested it can cause cyanosis (blue coloration of lips, fingernails or skin), as well as confusion, dizziness, headache, nausea, abdominal pain, unconsciousness, and convulsions.[2] Chronic exposure can also cause blood disorders.[2]

Regulations and Guidelines

Occupational Exposure Limits (OEL) [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21]

Canadian Jurisdictions OEL (ppm)
Canada Labour Code 0.01 [sk]
AB, BC, MB, NB, NL, NS, PE 0.01 [sk]
ON 0.0005 [sk]
QC 0.02 [sk, em]
NT, NU, SK 0.01 [sk]
0.03 [stel]
YT 0.02 [sk]
Other Organizations OEL (ppm)
ACGIH 2018 TLV 0.01 [sk]
ppm = parts per million
sk = easily absorbed through the skin
stel = short term exposure limit (15 min. maximum)
em= exposure must be reduced to the minimum
ACGIH = American Conference of Governmental Industrial Hygienists
TLV = threshold limit value (8 hour maximum)

Canadian Environmental Guidelines

Jurisdiction Limit Year
Ontario Ambient Air Quality Objective 24 hour: 10 μg/m3 2016[22]
BC’s Contaminated Sites Regulation, BC Reg 375 Sets soil standards for:
Agricultural and low density residential sites: 15 μg/g
Urban park and high density residential soil: 30 μg/g
Commercial and industrial soil: 350 μg/g
Drinking water standard: 0.5 μg/L
2017[23]
μg/m3 = micrograms per cubic metre
μg/g = micrograms per gram
μg/L = micrograms per liter

MOCA was not included in other Canadian environmental guidelines reviewed.[24,25,26,27,28,29]

Canadian Agencies/Organizations

Agency Designation/Position Year
Environment Canada’s National Pollutant Release Inventory Reportable to NPRI if manufactured, processed, or otherwise used at quantities greater than: 10 tonnes. 2016[30]
Health Canada DSL – high priority substance with intermediate potential for exposure 2006[31]
Agreement Respecting the Great Lakes Basin Ecosystem Listed as a “Hazardous Polluting Substance” 1987[32]
DSL = domestic substances list
MOCA was not included in other Canadian government chemical listings reviewed[33,34,35]

Main Uses

MOCA is primarily used as a curing agent for polyurethane elastomers and epoxy resins.[6] It has been used in research laboratories as a model compound for studying carcinogens.[1,6]

As of 2005 in Canada, MOCA was primarily used as a curing agent for polyurethane prepolymers. These prepolymers were used to make specialized, castable polyurethane products such as industrial tires and rollers, shock absorption pads, conveyor belting, sport boots, roller skate wheels, cameras, computers, electrical components and wear-resistant industrial products.[36] Newer information on Canadian uses was not found.

Canadian Production and Trade

Polyurethane products and epoxy resins are manufactured in Canada;[37,38,39,40] given that MOCA is used in conjunction with these processes, it is likely used in Canada. Companies such as Polymark Manufacturing, ACR Group, and Elastochem Specialty Chemicals manufacture polyurethane products in Canada.[38,40]

MOCA was not being produced in Canada in 2000, and new evidence for its production was not found.[36] In the same year, Canada imported 100 to 1000 tonnes of MOCA.[36]

No export or import data on MOCA was included in the TradeMap database.[41]

Environmental Exposures Overview

MOCA is not a naturally-occurring chemical, so any found in the environment is from industrial releases or spills.[36,42] Sources of environmental exposure include dermal exposure to contaminated soil and ingesting root vegetables grown in contaminated soil.[3]

Once released, MOCA will strongly adsorb to organic matter in soil or in sediment. Because of its low solubility in water, contamination of groundwater and surface water is unlikely.[3,42]

Para-occupational exposures may occur in family members of workers exposed to MOCA.[3]

Trace amounts of unreacted MOCA may be present in some plastic products, however because MOCA has a high molecular weight and low volatility, exposure in consumers is expected to be very low.[36]

No household products are listed as containing MOCA in the Household Products Database from the United States.[43]

A search of Environment Canada’s National Pollutant Release Inventory (NPRI) database yielded the following results on current potential for exposure to MOCA in Canada:

NPRI Database

NPRI 2015[44]
Search Term: ‘p,p’-methylenebis(2-chloroaniline)’
Results: 2 facilities
Category Quantity Industry
Released into Environment 0.003 t Plastic product manufacturing, rubber product manufacturing (2 facilities)
Disposed of 0.046 t
Sent to off-site recycling None
t = tonne

Occupational Exposures

The most important route of occupational exposure to MOCA is dermal absorption, followed by inhalation and ingestion.[6]

The main occupations exposed to MOCA include workers involved in its manufacture and in producing polyurethane and epoxy where MOCA is used as a curing agent.[1,6] MOCA has been detected on a number of workplace surfaces in MOCA and polyurethane production plants, which suggests potential dermal exposure for workers.[6,42] In a polyurethane factory, MOCA was detected in the air in areas where it was melted and used, indicating that chemical mixers and moulders would have the highest inhalation exposure to MOCA.[42]

CAREX Canada has not prioritized MOCA for exposure estimate development. This is because there is a lack of exposure monitoring data in the Canadian Workplace Exposure Database on which to base an estimate.

Sources

Photo: Wikimedia Commons, Perry Beall

1. National Toxicology Program (NTP). 14th Report on Carcinogens for Methylenebis(2-chloroaniline) (2016) (PDF)
2. US National Library of Medicine. Hazardous Substances Data Bank (HSDB) (Search term: “4,4′-Methylenebis(2-chloroaniline)”)
3. International Agency for Research on Cancer (IARC). IARC monograph summary, Volume 99 (2010) (PDF)
4. International Agency for Research on Cancer (IARC). IARC monograph summary, Volume 57 (1993) (PDF)
6. International Agency for Research on Cancer (IARC). IARC monograph summary, Volume 100F (2012) (PDF)
10. Government of Newfoundland and Labrador. Regulation 5,12 Occupational Health and Safety Regulations (2012)
11. Government of the Northwest Territories. Occupational Health and Safety Regulations, R-039-2015 (2016) (PDF)
13. The Canadian Legal Information Institute (CanLII). Government of Nunavut’s Occupational Health and Safety Regulations, Nu Reg 003-2016 (2010)
16. Government of Prince Edward Island. Occupational Health and Safety Act Regulations Chapter 0-1 (2013) (PDF)
18. Government of Saskatchewan. The Occupational Health and Safety Regulations, 1996 (2016) (PDF)
19. The Canadian Legal Information Institute (CanLII). Yukon’s Occupational Health Regulations, O.I.C. 1986/164 (2012) (PDF)
20. Occupational Safety and Health Administration (OSHA). Annotated PELs (2018)
22. The Canadian Legal Information Institute (CanLII). Ontario Drinking Water Quality Standards, O Reg 169/03 (2017)
23. Government of British Columbia. Contaminated Sites Regulation B.C. Reg. 375/96 (2017)
26. Health Canada. Cosmetic Ingredient Hotlist (2014)
27. Alberta Environment and Parks. Ambient Air Quality Objectives (2017)
28. Ontario Ministry of the Environment and Climate Change. Ontario’s Ambient Air Quality Criteria (2016)
29. The Canadian Legal Information Institute (CanLII). Regulation respecting the quality of drinking water, CQLR c Q-2, r 40 (2014)
32. International Journal Commission (IJC). Revised Great Lakes Water Quality Agreement of 1978 (1978) (PDF)
33. Environment and Climate Change Canada. Toxic Substances List – CEPA Schedule 1 (2010)
35. Canadian Council of Ministers of the Environment (CCME). National Classification System for Contaminated Sites (2008) (PDF)
36. Health Canada. State of the Science Report for a Screening Health Assessment Report, 4,4′-Methylenebis(2-chlorobenzenamine). (2005) (report available upon request)
38. Polymark Manufacturing. Polyurethane
40. Elastochem Specialty Chemicals. Cast Polyurethane
41. International Trade Centre. TradeMap (Free subscription required)
42. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for 4,4′-methylenebis(2-chloroaniline)(1994) (PDF)
43. US National Library of Medicine. Household Products Database (HBD)
44. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (Substance name: ‘p,p’-methylenebis(2-chloroaniline)’)

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