CHEMICAL CARCINOGENS

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CHEMICAL CARCINOGENS
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What is a carcinogen?

• Any substance that is capable of causing cancer.
• Cancer is the abnormal or uncontrolled growth of
  new cells in any part of the body, characterized
  by cells that tend to invade surrounding tissue
  and metastasize to new body sites.
• Carcinogens are chronic toxins. They cause
  damage after repeated or long-duration exposure.
  They may have not immediate apparent harmful
  effects, with cancer developing only after a long
  latency period.

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What are reproductive toxins?

• Mutagens cause damage to chromo-somes
  by introducing changes to DNA.
• Mutagens have adverse effects on fertility and
  general reproductive performance.
• Mutagens are chronic toxins

• Teratogens act during pregnancy to
  cause adverse effects on the embryo or fetus
  including malformations, retarded growth and
  post- natal deficiencies.
• Reproductive toxins can affect both men and women.

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What materials are carcinogens?

• Asbestos
• Certain chemicals
• Coal tars and coke oven emissions
• Hardwood sawdust (certain species)
• Ionizing radiation
• Natural products (progesterone, safrole)
• Tobacco smoke
• Ultraviolet radiation

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What is a chemical carcinogen?

• Any discrete chemical compound which has been
  shown to cause cancer in human or animal studies.
• Hundreds of individual compounds have been shown
  to induce cancers. Many thousands of additional
  compounds are suspect carcinogens.
• Many are commonly used in laboratory operations,
  shops and art studios.

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How is chemical carcinogenicity determined?

• Epidemiological studies determine the
  relationship between a cancer suspect chemical
  and a human population over a long period of
  time.
• Animal studies directly induce cancer in test
  animals using a large sample of animals, usually
  of two or more species with varying dose and time
  parameters.
• Experiments with animals are based on the premise
  that chemicals that produce cancer in animals
  will have similar effects on human cells. Most
  known human carcinogens produce cancer in
  experimental animals.

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What is an OSHA select carcinogen?

• Any substance that is regulated by OSHA as a
  carcinogen.
• It is listed under the category know to be
  carcinogens in the Annual Report on Carcinogens
  published by the National Toxicology Program
  (NTP).
• It is listed under Group 1 (carcinogenic to
  humans) by the International Agency for Research
  on Cancer (IARC).
• It is listed in either Group 2A (limited
  evidence of carcinogenicity from human studies)
  or 2B (sufficient evidence of carcinogenicity
  from animal studies) by IARC or under the
  category reasonably anticipated to be
  carcinogens by NTP. (A specified dose range is
  given.)

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Which classes of chemicals tend to be carcinogens?

• Epoxides Ethylene oxide Propylene oxide
• Organohalogen comp. Vinyl chloride Carbon
  tetrachloride Chloroform Hexachlorobenzene Trichl
  oroethylene
• Hydrazines Hydrazine (and salts) 1,2-Dimethylhy
  drazine

• N-Nitroso compounds N-Nitrosodimethylamine
• Aromatic Amines Benzidine Aniline o-Anisidine
  o-Toluidine
• Aromatic hydrocarbons Benzene Benzaanthracene
  Benzoapyrene

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Classes of carcinogens (cont.)

• Misc. organic compounds Formaldehyde Acetaldehyd
  e 1,4-Dioxane Ethyl carbamate 2-Nitropropane S
  tyrene Thiourea Thioacetamide

• Misc. inorganic comp. Arsenic and
  compounds Chromium and comp. Thorium
  dioxide Beryllium and compounds Cadmium and
  compounds Lead and compounds Nickel and
  compounds Selenium sulfide

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How do carcinogens enter the body?

• Skin absorption. Many solvents and other
  chemicals go directly through the skin.
• Ingestion. Swallowing of a carcinogen.
• Inhalation. Breathing gases, fumes and vapors is
  the most common form of exposure.

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What organs to carcinogens attack?

• Lungs
• Liver
• Kidney
• Reproductive system
• Skin
• Many other organs and tissues

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What factors influence the development of cancer?

• Dose--amount and length of exposure. The lower
  the dose the least likely you are to develop
  cancer or related diseases.
• Environmental or lifestyle factors.
• Cigarette smoking (co-carcinogen)
• Alcohol consumption (co-carcinogen)
• Diet--high fat consumption, natural antioxidants
• Geographic location--industrial areas, UV light
• Therapeutic drugs--some are known carcinogens
• Inherited conditions

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How do I reduce my exposure to carcinogens?

• Engineering controls--exhaust ventilation and
  equipment
• Personal protective equipment
• Personal hygiene
• Labeling and storage of containers
• Housekeeping and maintenance
• Regulated areas
• Decontamination and emergency procedures
• Monitoring
• Administrative controls

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Engineering controls--exhaust ventilation and
equipment

• General room ventilation--10 or more changes of
  air per hour. Designed to reduce exposures below
  the permissible exposure limit (PEL). Many
  carcinogens have a very low exposure limit. Use
  an ALARA policy.
• Fume hoods--full open face velocity of 8o to 100
  l.f.p.m.. combined with a dry ice capture test.
• Local ventilation--exhaust (sometimes supply) at
  the point of use of a chemical. Elephant trunk
  or slot hood.
• Carcinogen glove box or environmental chamber.
• Biosafety cabinet--used for anticancer drugs,
  viruses.
• No benchtop work in a laboratory setting.

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Personal protective equipment

• Respiratory protection--dust masks, respirators.
  Respirators are primarily for use in non-lab
  areas, except for emergency response (spill
  cleanup)--shops, floor stripping, construction
  operations (painting).
• Eye protection--safety glasses, splash goggles,
  face shields.
• Hand protection--gloves, protective sleeves.
• Protective clothing--lab coats, aprons, Tyvek
  garments.
• OSHA standards for personal protective equipment
  supersede other OSHA standards.

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Personal hygiene

• No smoking, eating, drinking or application of
  cosmetics is permitted in areas where carcinogens
  are in use (or in any lab area!). No mouth
  pipetting!
• Wash hands and any exposed skin if potentially
  contaminated--face, neck, forearms, etc.
• No shorts or open toed shoes.
• Remove lab coat or other potentially contaminated
  protective clothing before leaving the work area.
  Lab coats need to be cleaned regularly special
  washing instructions may be needed. Contaminated
  disposable clothing should be treated as
  hazardous waste

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Labeling of containers

• All containers of chemical carcinogens need to
  have a warning label affixed to them. A
  Right-to-Know (RTK) style label must be on any
  container of material that is repackaged or made
  into a solution more than 0.1.
• All areas where carcinogens may be used, present
  or stored should have prominently displayed
  warning signs or labels both in the areas and
  access to them.. Some warning signs and labels
  are described by specific standards.
• DANGER--Contains ___________
  CANCER HAZARD

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Storage of containers

• Carcinogens must be stored separately from other
  materials.
• Separated by shelving system or secondary
  containment.
• Secondary containment means placing chemical
  containers in an outer container to prevent the
  release of a chemical in the event that its
  container breaks or ruptures.
• Desiccators, plastic boxes, bottle-in-can are
  acceptable secondary containment.
• Storage areas must be labeled Danger--Carcinogens
  Stored Here.

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Housekeeping and maintenance

• Keep all work surfaces and equipment clean.
• Dry sweeping or compressed air cleaning of floors
  or work surfaces is prohibited.
• Dry cleaning of surfaces and equipment must be
  done by vacuum systems with high-efficiency
  filters.
• All contaminated floor sweepings, debris (paper
  towels, Kimwipes, plasticware), discarded filters
  from respirators or vacuums must be bagged,
  properly labeled and sent out for incineration.

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Regulated areas

• Establish regulated or designated areas for the
  use of carcinogens. (Required in Lab Standard.)
• Locations where entry and exit or use of an area
  is restricted to the use of carcinogens.
• Only authorized persons trained in the use of the
  carcinogens present may use these areas when such
  materials are in use.
• Regulated areas are usually under negative
  pressure (fume hood) to contain carcinogens in
  the hood or room.

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Decontamination and emergency procedures

• Safety shower and eyewash station nearby.
• Special solutions or solvents on hand if required
  for decontamination of skin, eyes.
• Spill mixtures and cleanup materials for spills
  on hand.
• All used spill cleanup materials must be treated
  as hazardous waste.
• Respirator may be needed for spill cleanup.
• Any incidental spill may be cleaned up by the
  lab staff larger spills may require a emergency
  response (5-1111).
• Fire extinguisher at hand as required. Training
  needed.
• Written emergency response plan. Training
  required.

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Monitoring

• If there is reason to believe that a PEL may be
  exceeded then personal exposure monitoring is
  required. This may be done by EHS staff.
  Personnel monitoring with sample pumps or badges.
• Area monitoring may be required in some cases.
• Medical monitoring may be required if it is
  anticipated that PELs may be exceeded.
  Examination by a physician, blood tests, etc.
  Required whenever there is a spill or other
  emergency.
• Results of monitoring must be supplied to the
  employee.
• Records of exposures,. monitoring, and medical
  exams must be kept for 30 years.

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Administrative controls

• Material Safety Data Sheets and other
  information.
• Training--all employees using carcinogens must be
  trained in the recognition of the physical and
  health hazards associated with the carcinogens
  they are working with, methods to detect the
  presence or release of a carcinogen and ways to
  protect themselves from exposure to the
  carcinogens with which they are working.
• Specialized training may be required for specific
  carcinogens.
• Written exposure control plans, if required.
• Limitations on the duration of exposure.

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How do I dispose of waste carcinogens?

• With very few exceptions (dilute formaldehyde
  solutions) carcinogens may never be discharged to
  the sanitary sewer.
• Carcinogens may never be disposed of in the
  ordinary trash.
• Waste bottles must be properly labeled, tightly
  capped at all times (except when adding or
  removing waste) and they must have secondary
  containment. See section 7.9-11 of the CHP for
  waste bottle labeling instructions. Check
  Poison on the waste label.
• Dry wastes must be incinerated or shipped out as
  regulated medical waste (chemotheraputic
  agents).

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How do I reduce my inventory and level of waste
generation?

• Plan the use of carcinogens carefully. Do not
  make more stock solutions than are required.
• Substitute less hazardous materials for
  carcinogens whenever possible toluene instead of
  benzene.
• Purchase carcinogens in the smallest possible
  quantities.
• Do not allow inventories to accumulate. Place no
  longer needed materials in a recycling program or
  dispose of as waste.
• Detoxify carcinogens as part of your research
  protocols. Formaldehyde is easily detoxified by
  NH4OH, for example.

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The Standard Operating Procedure (SOP)

• Standard Operating Procedures (SOP) relevant to
  safety and health considerations need to be
  developed when carcinogens are in use. An SOP
  may be developed for an individual carcinogen, a
  process or a class of chemicals.
• An SOP must contain the following The name and
  location of the chemical, purchasing and usage
  authoriza-tion, training requirements, location
  of use, PPE required, methods of waste disposal,
  decontamination, first aid measures, spill
  control, emergency phone numbers and any other
  relevant information.
• Employees must be trained in the content of the
  SOP.

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The End

• There are old researchers and there are bold
  researchers, but there are no old, bold
  researchers!
• Anon.