Guidelines for Safe Handling and Use of

Polymeric MDI

Polymeric MDI - Safe Handling/Use

Isocyanates/Diisocyanates are reactive chemicals.

Many specific compounds in this family of chemicals - characterized by -NCO functional groups. Chemical/Physical properties of specific compounds vary

Used for over 40 years to make a variety of polyurethane products in home & industry.

Used since the mid 1980s in the forest products industry to make OSB.

Polyurethane Products

Paints, varnishes Automobile parts (bumpers, dashboards,

headliners, armrests, seats, carpet underlayment,)

Binder for wood products (OSB, MDF, etc.) Insulation in home appliances, buildings (roofs,

walls). Footwear, sports equipment. Pillows, mattresses, clothing

Physical Properties of PMDI/MDI

Brown liquid having consistency of motor oil. Reacts with water for form solid polyureas and

carbon dioxide. Poor odor warning properties (odors are

however subjective). Very low vapor pressure (VP)

VP of water ~1.8 million times greater

Polymeric MDI - Safe Handling /Use Prevent exposures - prevent risk of injury Use a combination of effective control

measures Engineering - enclosures, local exhaust ventilation Administrative - work practices, controlled access Personal Protective Equipment - gloves, respirators etc.

Control measures must be properly maintained for them to be effective.

Engineering - - - PPE (least preferred)

Exposure Limits

Airborne concentrations of substances… To which nearly all workers may be repeatedly

exposed.. Day after day for a working lifetime.. Without adverse health effects.

Philosophy Behind Setting Exposure Limits

Based on acceptable risk All chemicals are toxic at some

concentration A concentration exists at which no

significant injurious effect should occur

Routes of Exposure to Chemicals

Inhalation - breathing the air in which the chemical is suspended

Skin and eye contact Ingestion (least significant route of exposure)

Exposure Limits - MDI

OSHA Permissible Exposure Limit (PEL) - USA 0.2 mg/M3 = 0.020 ppm, ceiling (legally binding)

ACGIH Threshold Limit Value (TLV) - USA 0.051 mg/M3 = 0.005 ppm, 8-hr TWA (good recommended practice)

For comparison, vapor pressure of MDI at room temperature is about 0.006 ppm, with no ventilation

Effects of Overexposure - MDI Irritation of the respiratory tract, eyes, nose

Symptoms may include sore throat, chest tightness, wheezing, coughing

Respiratory sensitization - occupational asthma Difficulty breathing, asthmatic symptoms Symptoms may be immediate or delayed or both Exposure limits may not be protective To prevent symptoms, avoid exposures If early diagnosis, good chance of recovery; however, there

are no guarantees

Agents Which Can Cause Occupational Asthma

Naturally Occurring Products Animal dander, latex proteins, insect debris, flour, tobacco

dust, moldy compost, rosin(fluxes), soybean dusts, wood dusts, mushroom dusts….

Synthetic Products Metal salts (Ni, Cr, Pt), Persulfates, Penicillin, Tetracycline,

Amines, Formaldehyde, Diisocyanates,...

Effects of Overexposure - MDI

Eye Contact Pain, irritation, possible corneal burns if not treated

Skin Contact Brown discoloration - hardens, eventually peels off Skin rash - prolonged, repeated contact - skin sensitization Respiratory sensitization?? - data inconclusive - avoid skin

contact Ingestion

Irritation of digestive tract Practically non-toxic by this route (= table salt)

Air Monitoring for MDI

Direct Reading Methods - Screening Paper tape technology - color change Interpret results with caution Results at best semi-quantitative

Indirect Methods Treated filter papers or impingers Requires laboratory analysis Highly accurate and precise

Scott Bacharach SureSpot Monitor

Scott Bacharach AutoStep Plus Direct Reading Monitor

Polymeric MDI - Safe Handling/Use Medical Surveillance

Medical history with emphasis on the respiratory tract

Pulmonary Function Testing (PFT) Baseline Periodic (if symptoms of over exposure occur)

Recommended by all suppliers of MDI/PMDI Not required by law

Personal Protective Equipment - PPE Gloves - nitrile, butyl, or neoprene rubber Coveralls - Tychem SL (Saranex) or Tyvek QC

(PE) laminated Respirators

Supplied-air (historically) - if airborne levels warrant use Recent change in OSHA respirator standard

May be OK to use air-purifying respirators for some applications if certain conditions are met.

Boots - same materials as gloves Engineering controls most preferred

Personal Protective Equipment:Appropriate Use

Disposable gloves are sufficient for most production situations

Coveralls, boots and respirators typically only required when loading large storage tanks or cleaning up very large spills (more than 20 gallons)

Spills Don protective equipment If needed, monitor to evaluate airborne levels Contain spill with absorbent material (sand, dirt,

spill kit, etc.) Mix well and shovel into containers - move

outside, do not seal Add decon solution and mix well - let stand Dispose of solids/liquids per State or local

regulations

Decontamination solutions

Type A Water (90%) Concentrated Ammonia (8%) Liquid detergent (2%)

Type B Water (90-95%) Sodium Carbonate (5-10%) Liquid detergent (0.2-0.5%)

MDI Under Fire Conditions

Not readily ignitable (35 kg) Heptane (1L) added to enable MDI to burn Mass burned for several minutes after ignition

Fire subsided, then ceased leaving behind a dark residue ~80% of original sample weight.

Offgassing products - CO2 (47%); CO (180 ppm): Nox (30 ppm); HCN (15 ppm); MDI (1.8 ppm)

Concern for responders - use same PPE as for typical structural fires

Comparison: Gaseous Combustion Products of Untreated and Treated Wood (mg/g)

Com.Products

untreated 6% PMDI 10% PF 8% UF

CO 137 124 173 131

CO2 383 339 402 384

HCN 0.6 0.75 0.5 1.55

NOx 0.24 0.12 0.10 0.26

Re-evaluation of Diisocyanates Data for Cancer Classification - IARC

Status of TDI and MDI reviewed in 1998 Data made available for both Human evidence inadequate to change

classification for TDI - remains category 2B - possibly carcinogenic to humans.

Insufficient new data available to warrant a full scale review for MDI - remains category 3 - not classifiable as to carcinogenicity to humans.

IARC Classification Scheme for Cancer

Category 1: Sufficient evidence of cancer in humans - asbestos, wood dust, VC

Category 2: probably carcinogenic to humans 2A - Limited evidence to humans: Be, acrylonitrile, 2B - Sufficient evidence in animals, inadequate data in

humans - Cd, DDT, TDI, formaldehyde, Category 3: not classifiable as to

carcinogenicity to humans - Cyclamates, Saccharin, MDI,

Environmental Issues MDI is listed as a Hazardous Air Pollutant (HAP) MDI invalidated by court of appeals as a high

risk pollutant under the US Clean Air Act. MDI removed from EPA’s Urban Toxics listing

of chemicals presenting the “greatest threat to public health”. Overestimated emissions reporting by industries Improper assumptions in calculating emissions by

consultants. Petition filed in 8/98 with EPA to exempt MDI as

a VOC - inhibits ozone formation (CA study).

Environmental Fate of MDI*

The half-life of MDI is short (0.6 - 32 hours) and will have a limited tendency to accumulate in environment due to air emissions.

Spills are not likely to release MDI in either vapor or aerosol form; therefore, significant airborne levels are not expected.

The reactions that occur after spills (solids and water insoluble polyureas) limit further exposure to airborne MDI.

* Manitoba Environment, Report 96-08

Polyol Formulations High molecular weight polyester and polyether

polyols - major component Generally regarded as non-toxic and non-hazardous

Catalysts and mold release agents - minor component in polyol formulation (0.1- 5% typically) Occasionally caustic (irritants, corrosives, skin absorption

for some but not many Occasionally odorous Use local exhaust ventilation and PPE to prevent exposure,

if indicated by MSDS

The Bottom Line:

Use common sense when handling all kinds of chemicals. Maintain a sense of perspective.

All chemicals have some degree of toxicity. Any chemical is toxic if the amount consumed

(dose) is large enough. People drown in water, suffocate in pure nitrogen

Toxicity and hazard are not the same Toxicity - ability to cause damage in living systems Hazard - risk/likelihood of injury - depends on how used

Exposure doesn’t necessarily mean harm - depends on dose.

The Bottom Line:

Benefits are provided by end products made from isocyanates/diisocyanates.

There are risks associated with any activities we undertake Handling/using chemicals - no exception All chemicals can produce adverse health effects and be

hazardous - depends on how they are handled/used. Risk of injury can be real or perceived. Risk is minimized or eliminated when chemicals

are properly handled.

For further information, contact…

Harry D. CoffeeNautilus Composites LLC575 Walnut Ridge TrailAurora, OH 44202(330) 995-2636 office(216) 496-8921 cellhdcoffee@adelphia.net