Organic SolventsFriend or Foe?

Mary F. McDaniel, DO, JD, MPHMcDaniel Lambert, Inc.

mfmcdaniel@mclam.com

May 31, 2005

What are organic solvents?

Organic solvents Organic - contain carbon and hydrogen Low molecular weight Lipophiolic (“fat-loving”) Volatile (evaporates readily) Liquid at room temperature

Used in a wide range of industries and essential to many manufacturing processes

Solvents dissolve fats and greases and other materials (rubber, plastic, etc.,) Predominantly used as cleaners and degreasers

Other uses include controlling viscosity and drying rates, and as raw materials in other products Thinner/mixer for pigments, paints, glues,

pesticides, and epoxy resins

How are people exposed to solvents?

Occupational exposure Inhalation of vapors Dermal contact - solvents penetrate the skin and pass into the

blood

Environmental exposure Living near industrial producers or users Use of household cleaning products, paints, etc. Exposure to contaminated water, soil, air, or food

Recreational “drug” use Inhalation of paints, glues, and other products

What are the general effects of solvent exposure?

Potential for acute and chronic effects including Reversible and nonreversible abnormalities in the

central and peripheral nervous systems Damage to the liver, kidneys, lungs

Factors influencing effects Solvent type Amount Duration of exposure

Indoor Air - Vapor Intrusion

Volatile chemicals in contaminated soil or groundwater can migrate through subsurface soils and into indoor air spaces of overlying buildings

Love Canal

70-acre industrial landfill located in Niagara Falls, New York

Landfill originally a canal excavated in the 1890s for an unfinished hydroelectric project

From 1942 - 1952, Hooker Chemicals and Plastics (Occidental Chemical Corporation) disposed of 21,000 tons of hazardous wastes in the canal – including solvents

Love Canal

Despite the desire of Hooker Chemical for the site to be used only for open space, the area was eventually covered and the property developed…including the construction of an elementary school

Included in the deed transfer was a "warning" of the chemical wastes buried on the property and a disclaimer absolving Hooker of any further liability

Complaints of odors and chemical residues begin in the 1960’s, increased in the 1970’s as heavy rainfall caused the groundwater to rise, flooding area basements

Love Canal – Spring 1978

2 rings of homes border landfill

99th Street Elementary School

White patches indicate areas without vegetation – leaching?

Love Canal

May 1978 - EPA concluded from basement air sampling that vapors are a serious health threat

August 1978 – President Jimmy Carter declared the Love Canal area a federal emergency

More than 900 families were forced to leave their homes

Site publicity directly spurred passage of EPA’s Superfund law in 1980

December 1995 - Occidental ordered to pay $129 million settlement

Residents returned to portions of the site in late 1990’s Epidemiological study into potential health effects ongoing

General Solvent Types

Chlorinated Solvents - widely used in cleaning and degreasing trichloroethylene (TCE), 1,1,1-trichloroethane (TCA),

tetrachloroethylene (PCE), carbon tetrachloride, etc.

Petroleum Distillates - primarily used as fuels, but also used as cleaning agents Petroleum naphthas and petroleum ethers are typically used

as solvents - Stoddard solvent, mineral spirits

Other Synthetic Organic Chemicals – pesticides, PCBs, etc.

Industrial Solvent Uses

INDUSTRY USAGE SOLVENT TYPE

Adhesives • component cleaning agent

• aliphatic or chlorinated hydrocarbons

Antifreeze • component • glycols

Chemical and pharmaceutical industry

• used for chemical reactions

• a range of solvents

Dry cleaning • cleaning agent • chlorinated solvents

Engineering industry • degreasing metal and plastic surfaces

de-watering

• trichlorothylene isopropanol

Paints, printing inks • component cleaning agent

• hydrocarbons (e.g. white spirit)

xylene toluene

Chlorinated Solvents

Carbon tetrachloride - first chlorinated solvent to come into general use (early 1900s) First widespread uses were household cleaning agent and a fire

extinguishing fluid Some medicinal use as a hookworm treatment in animals and,

primarily in tropical regions, in humans In 1929 DuPont and General Motors produced the first

chloroflourocarbons (CFCs) using "Freon“; production and use now prohibited

Tetrachloroethylene - widely known as a dry-cleaning solvent Was used in cleaning and degreasing in various textile production

processes Was used in the production of fluorinated compounds such as

CFC-113

TCE - trichloroethylene

Major environmental releases Air emissions from industrial

degreasers Industrial wastewater

OSHA exposure limit 100 ppm in air (8-hour day/40-hour

week)

US EPA drinking water limit and CA MCL 5 ppb

TCE Health Effects

Acute exposure to TCE in air: CNS effects - Dizziness, headache, lightheadedness Eye, nose, and throat irritation Nausea and vomiting Exposure to large amounts may cause heart problems

such as cardiac arrhythmias

Chronic exposure: Nerve, kidney, and liver damage Animals – increased liver, lung, and kidney tumors Humans – probable carcinogen

TCE Monitoring

Recent exposure Breath, blood, and urine tests

Up to a week following exposure blood and urine test for TCE and metabolites

Some metabolites may result from exposure to other similar chemicals – so not absolute proof of TCE exposure

Perchlorate – not a solvent, but…

Naturally occurring and manmade inorganic contaminant increasingly found in groundwater, surface water, and soil

Mostly used as an ingredient in solid fuel for rockets and missiles

Other products - safety flares, aluminum refining, electroplating, and the production of paints

Perchlorate Health Effects

Primary health concern is the interference with the uptake of iodide, an essential nutrient, by the thyroid gland Inadequate iodide uptake may lead to the harmful disruption

of proper thyroid function

In the 1950s perchlorate was approved by the U.S. FDA to treat people with overactive thyroid glands

Perchlorate in drinking water

Perchlorate contamination reported in at least 20 states

As of May 2005, detected in 375 California drinking water supplies at concentrations ranging from 3.3 to 820 ppb

California Public Health Goal – 6 ppb

245 ppb

6 ppb

24.5 ppb

No effect dose (NOEL) from human volunteer study identified by National Academy of Sciences (NAS)

Safe drinking water level based on safe dose recommended by NAS (0.0007 mg/kg/day)•Includes additional safety factor to protect most sensitive group – the fetus•U.S. EPA Drinking Water Equivalent Level

Perchlorate Drinking Water Levels & Safety Factors

CA Public Health Goal/Notification Level•Assumes people also ingest perchlorate from food (so less allowed in water)•Based on same NAS no effect dose, but lower statistical value