LABORATORY AND FIELD SAFETY Millie Tran and Sheryl Mansour Environmental Health and Safety Department San Diego State University (619) 594-6778
Areas of Regulatory Oversight for Laboratory Safety • Radiation Safety Radiation Safety Committee – RUA Mitch Lanahan RSO - (619) 594-6879 • Biological Safety Institutional Biosafety Committee – BUA Millie Tran, Sheryl Mansour BSO – (619) 594-2865/6965 • Chemical Safety Environmental Health & Safety Department Alvin Shoemaker, Charles Adkins (619) 594-6098/2857 – HazMat/HazWaste Millie Tran, Sheryl Mansour (619) 594-2865/6965 – Chemical Hygiene
Work with Hazardous Chemicals Welcome! This Laboratory and Field Safety Training is for employees who work in a laboratory or out in the field where hazardous chemicals are being handled or stored.
Cal OSHA Occupational Exposure to Hazardous Chemicals in the Laboratories Regulation Cal OSHA Occupational Exposure to Hazardous Chemicals in the Laboratories • The California Occupational Safety Health Administration (Cal OSHA) has determined that lab or field work typically differ from industrial operations in the handling and use of hazardous chemicals;thus, establishing the Occupational Exposure to Hazardous Chemicals in the Laboratories Regulationto protect lab or field workers. • The key elements of this regulation are as follow: • A written Chemical Hygiene Plan must be created and accessible to employees when hazardous chemicals or hazardous operations are involved. • Employees shall be protected from occupational exposure to hazardous chemicals. • Employees shall be provided and informed of the Material Safety Data Sheets (MSDSs) and other reference material. • Employees shall be informed of the hazardous chemicals present in the lab/field or of the hazardous operations in which they are involved. • Employees handling hazardous chemicals must be appropriately trained before doing any work involving hazardous chemicals or hazardous operations. • Engineering controls and personal protective equipment must be provided, maintained, and replaced when necessary. • Employees must be informed of the procedures to follow to respond to emergencies.
Basically, this CalOSHA regulation requires the following provisions to ensure health and safety of lab/field employees handling hazardous chemicals: • Avoid underestimation of risk • Minimize all chemical exposures • Observe exposure limits • Institute chemical hygiene plan
Chemical Hygiene Plan The Chemical Hygiene Plan is a chemical safety manual for laboratory workers that contains: • Basic standard operating procedures (SOPs). (Lab-specific SOPs must be created.) • Criteria used to determine and implement control measures from exposure to hazardous chemicals. • Circumstances requiring prior approval before application of hazardous lab operation, procedure or activity. • Provision for additional employee protection for work with particularly hazardous substances such as “select carcinogens”, reproductive toxins, and highly acute toxins.
Standard Operating Procedures (SOPs) Standard Operating Procedures (SOP's) are written procedures explaining how to safely work with hazardous chemicals. Lab-specific SOPs are required for any work with hazardous chemical or any application of hazardous operations specific to the protocol or if not already developed in the chemical hygiene plan’s general standard operating procedures. The Chemical Hygiene Plan (CHP) contains basic SOPs for: • Handling Common Hazardous Chemicals • Labeling of Chemicals • Storing of Chemicals • Responding to Small Lab Spills However, labs must create SOPs for procedures/chemicals not in CHP such as : • Select Carcinogens • Highly Toxic Chemicals
Question The Occupational Exposure to Hazardous Chemicals in the Laboratories Regulationis a CalOSHA regulation requiring that lab employees shall be protected from occupational exposure to hazardous chemicals, be informed of the hazardous chemicals present in the lab/field, and be trained before doing any work involving hazardous chemicals in academic and research labs. • True • False
Question Which statement about the Chemical Hygiene Plan is correct? • It is a campus policy. • It contains general Standard Operating Procedures (SOP) that must be supplemented with lab-specific SOPs. • All lab staff must be familiar with it. • All of the above.
Hazard Identification/Assessment In order to incorporate safety aspects of handling and storage into your standard operating procedures, you must understand and recognize the hazards associated with the • materials, • equipment used, and • procedures performed.
Physical Hazards Chemicals that release energy in a violent fashion either by their natural chemical composition or by the manner they are handled can become a physical hazard. These materials can be safely used if the specific hazard(s) are understood. The main physical hazards at SDSU are: • Flammable and Combustible Liquids • Oxidizers • Peroxidizable chemicals • Explosives • Reactive materials • Pyrophoric • Compressed gases
Flammable & combustible liquids are some of the most commonly used hazardous chemicals at SDSU. The National Fire Protection Agency (NFPA) places flammable liquids and combustible liquids in different classes based on their flash points. Flammable liquid has a flash point below 100° F. Combustible liquid has flashpoints over 100° F. Examples of common flammable/combustible liquids: Alcohols- ethanol, methanol, isopropanol Ketones – acetone BTX – benzene, toluene, xylene ethyl ether, ethyl acetate Most organic chemicals are also flammable or combustible. Flammable & Combustible Liquids
Flammable & Combustible Liquids To safely work with flammables observe the following guidelines: • Keep flammables/combustible materials away from sources of ignition, open flames, hot surfaces, electrical equipment and static electricity. Do not store with acids or bases. • Store flammable liquids in NFPA approved containers or inside cabinets or storage rooms designed for flammable materials. • Small squirt bottles containing a volume of less that one-liter can be stored on the bench top. Larger volumes (>1 liter) need to be stored appropriately. • Assure fire extinguishers are in the area.
Oxidizing Chemicals Oxidizers are materials which can react with other substances promoting combustion by giving off electrons and undergoing reduction. These reactions can result in a fire or an explosion. Examples of common oxidizers are: • Nitrous oxide • Hydrogen peroxide • Nitric acid • Perchloric acid • Nitrates • Oxygen • Sulfuric acid
Oxidizing Chemicals To safely work with oxidizers observe the following guidelines: • Oxidizers are incompatible with organics. Store oxidizers separate from organics. • Use oxidizers with extreme care and consult the MSDS for specific guidelines.
Peroxidizable Chemicals Peroxidizable chemicals can undergo auto oxidation to form organic peroxides that can become explosive with impact, heat or friction. These chemicals may become more hazardous as they age; peroxides may form even when the container has not been opened. Examples of common peroxide formers in SDSU labs include: • Ether • Dioxanes • Isopropyl ether • Tetrahydrofuran Never open a bottle that has solid formation around the lid. (Friction caused by unscrewing the cap can lead to explosion.) Contact the EHS for safe disposal.
Peroxidizable Chemicals Good management of peroxidizable materials starts with: • Dating all peroxide formers upon receipt and again after opening • Dispose of, or test for peroxide formation at the expiration date or 18 months if the container has not been opened. To safely work with oxidizers observe the following guidelines: • Never open a bottle that has solid formation around the lid. (Friction caused by unscrewing the cap can lead to explosion.) Contact EHS for safe disposal.
Reactive and Pyrophoric Reactive materials can release heat or a toxic or flammable gas upon contact with water. • Safe handling of these materials will depend on the specific materials and the conditions in which this material is handled. • Consult the MSDS for the specific chemical for safe handling instructions and to develop an SOP for the operation. Examples • Sodium metal • Lithium aluminum hydride Pyrophoric materials can react with air and ignite spontaneously at or below 113°F. • Pyrophoric materials should be handled and stored in inert environments. Examples: • silane • white or yellow phosphorous
Question Peroxides and peroxide-forming chemicals: • Must be dated when received and when opened. • Can explode if subject to heat, shock or friction. • Should be tested for peroxide formation at the expiration date because they become more hazardous as they age. • All of the above.
Compressed Gases Compressed gases may pose a physical and/or health hazard depending on the gas being used. Restraint: • Gas cylinders with regulators must be individually secured. • Only cylinders with safety caps can be group chained. Individually Secured Group Chained When transporting a cylinder don't forget to: • Use appropriate cart • Secure cylinder in an upright position • Make sure safety cap is in place
Compressed gas containers must be handled with care and should be stored taking into account the property and hazard of the gases contained. This information can be found in the MSDS of the material. • Store in areas separate from external heat sources such as flame impingement, intense radiant heat, electric arc, or high temperature steam lines. • Store at least 20 feet from highly combustible materials such as oil or grease. • Store or transport in a manner to prevent them from tipping, falling or rolling.
Flammable gases (i.e. propane, hydrogen) must be stored in areas away from sources of ignition and kept separate from oxidizing gases (i.e. oxygen). • Poison/toxic gases (NFPA H=3 or 4) i.e. chlorine, carbon monoxide, phosgene or ammonia can pose serious potential hazards to personnel and therefore special storage and handling measures are required. Poison gases must be stored as follows: • Small size cylinders (fit inside hood) • Use and storage in hood • Large size cylinders (regular use) – • Use and store in ventilated cabinets with air monitoring and alarm system
Health Hazards A person must be exposed (inhalation, skin absorption, ingestion) to a health hazard for it to cause harm or health effect. The level and duration of exposure determines the severity of the health effect. The effects of exposure to hazardous chemicals vary with the amount of exposure or "dose."
Health Hazard We will discuss basic toxicology principles, then specific health effects that a chemical exposure will cause. The dose-response relationship is important in understanding the cause and effect relationship between chemical exposure and health effects. All chemicals are toxic at a high enough dose… Dose- Response Relationship 1- No-effect range (Safe region) 2- Range of increasing effect with increasing dose 3- Maximum effect range Our goal is to reduce workplace exposures to the level where no adverse effects are observed, into the safe region of the dose-response relationship.
Lethal Dose 50 • One of the most commonly used measures of toxicity is the LD50. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material. • The LD50 is the single dose that is lethal to 50% of the animals tested. A chemical with a low LD50, like osmium tetroxide is highly toxic. • The LD50 however, says nothing about the non-lethal toxic effects of chemicals. Some chemicals may have a high LD50, but may produce toxic effects at very small exposure levels, Sulfuric acid has an oral (rat) LD50 of 2,140 mg/kg, but may be corrosive at concentrations as low as 15%, causing severe burns at very low quantities.
LD50 values for substances tested in the rat SubstanceLD50 (mg/kg, oral, rat) Vitamin C 11,900 Ethyl alcohol 7,060 Bromine 2,600 Osmium tetroxide 162 (mouse) DDT 100 Nicotine & salts 50 How should an LD50 value be used? • As an aid in developing emergency procedures in case of a major spill or accident. • As an aid in developing guidelines for the use of appropriate safety clothing and equipment. For example, if the dermal LD50 value for a chemical is rated as extremely toxic, it is important to protect the skin with clothing and gloves made of the right chemical-resistant material. • As part of the Material Safety Data Sheets. Remember, the LD50 is only an approximate figure so that lethal toxicity can be compared. It says nothing about levels at which other acute toxic, but non-lethal effects might occur.
Permissible Exposure Limit (PEL) • PELs are regulatory limits on the amount or concentration of a substance in the air. PEL's are based on an 8-hour adult time weighted average (TWA) exposure. • PEL's refer to airborne concentrations of substances that may be inhaled. • When working with materials that have a low PEL (< 50ppm), use administrative and engineering controls to minimize the generation of a vapors or dust in the first place. If these controls are not sufficient, use appropriate personal protective equipment.
Carcinogen Substances associated with the occurrence of cancer in animals or humans are called carcinogens. • In the research laboratory, chemicals that have been deemed to be carcinogens will be labeled as such on the manufacturer's bottle. As with other chemicals, MSDS will provide further detail about the chemical hazards, means of exposure and necessary precautions. Further, a list of carcinogens can be found in the CHP. • Carcinogens are a chronic hazard. That is, they do not cause harm upon initial exposure, but rather take repeated exposures over many years. Common lab carcinogens and their uses are: • Chloroform - laboratory solvent • Formaldehyde - tissue preservation • Carbon tetrachloride - laboratory solvent
Carcinogens Safe Work Practices In general, keep exposure as low as possible by: • Using engineering controls, such as fume hoods or glove boxes. • Using PPE such as eye protection, lab coat and gloves. • Keeping quantities to a minimum. • Labeling bottle and storage area with the words carcinogen or cancer hazard. • Developing an SOP.
Sensitizers Sensitizers are a group of chemicals that will cause, through an immune response, the exposed person to become allergic to the chemical. Upon sensitization, small exposures will illicit abnormally severe responses. • A common lab example is formaldehyde. Exposure to formaldehyde/formalin can cause a sore throat and other respiratory problems if inhaled, and eczema-like symptoms upon repeated skin contact. • Sensitization can occur either from skin contact, or from inhalation. • Note that a person who has allergic reactions to a chemical upon the first exposure is considered a sensitive individual. • Sensitizers are also chronic health hazard. Examples of sensitizers: • Formaldehyde/Formalin • Latex
Reproductive Hazards • Reproductive toxicity is a sub-chronic hazard that some research chemicals have. These can be either mutagens or teratogens. Mutagens can cause damage to the genes, causing heritable mutations and abnormalities in the offspring. Examples: • Ethidium bromide • Formaldehyde, nicotine Teratogens cause harm to the fetus or embryo during pregnancy, but the mother does not show any signs of toxicity. Examples: • Ethyl alcohol • Mercury compounds
Corrosives and Irritants Corrosives has a low or high pH (<2.0 or >12.5). Therefore, acids and bases are corrosive. If corrosive chemicals come in contact with skin or eyes, they cause irreversible and visible damage at the site of contact. The damage will be acute. Examples: • Hydrochloric acid • Ammonium hydroxide • Acetic acid Irritants will cause reversible, but still painful, inflammation when in contact with the skin, eyes, nose or respiratory tract. Examples: • Chlorine and ammonia containing products • Diluted acids • Halogens • Nitrogen dioxide • Alkaline dusts and mists • Ozone • Phosphorus chlorides • Hydrogen chloride • Phosgene • Arsenic trichloride • Hydrogen fluoride • Diethyl/dimethyl sulfate
Question The LD50 of a material refers to dose or amount of material that will cause toxic effects in test animals. • True • False
False The LD50 is the single dose that is lethal to 50% of the animals tested. However, the toxic effects of a chemical are not determined by the LD50.
Minimizing Contact with Chemicals The risk of exposure to particularly hazardous substances can be reduced by: • Substituting whenever possible for less toxic /hazardous materials • Using as little material as possible • Handling inside a fume hood • Minimizing contact by the use of Personal Protective Equipment • Developing a written SOP for operations involving highly toxic materials
Chemical Storage Guidelines • The storage area and cabinets should be labeled to identify the hazardous nature of the products stored within. • Ensure that all chemicals are stored according to compatibility. (e.g., oxidizers such as sulfuric and nitric acid away from organics such as acetic acid and acetone).
Flammables storage • Flammable materials kept outside a cabinet should be in safety cans. • Flammable liquids (>1L) must be stored inside flammable cabinets. Never store flammable liquids in a standard (non-explosion/fire proof) cabinet. Example: i.e. acetone, hexane, acetic acid, phenol, and chloroform • Flammables include organic liquids, combustibles, organic acids and halogenated solvents. Halogenated solvents are not flammable, but this is the appropriate place to store them.
Acids Storage • Store by acid class in separate secondary containment • Organic • Acetic Acid • Formic Acid • Citric Acid • Benzoic Acid • Butyric Acid • Propionic Acid • Inorganic • Hydrochloric Acid • Hydrofluoric Acid • Hydrobromic Acid • Phosphoric Acid • Chromic Acid • Oxidizing • Nitric Acid • Perchloric Acid • Sulfuric Acid
Bases Storage • Store in secondary containment • Store away from acids and solvents • Cannot be stored at or above eye level. • Examples: • Hydroxides • Amines • Ammonia • Bleach
Corrosive and flammable materials should be stored below eye level. • Dry chemicals can be stored on shelves. • Chemicals should not be stored on the floor except in approved shipping containers.
Concentrated perchloric acid should be stored alone in a cabinet by itself.
Hazard Control Methods Hazard control methods must be implemented by the lab supervisor to reduce employee exposure to hazardous chemicals in the laboratory. This section covers the three types of hazard control methods to reduce employee exposure to workplace hazards: • Administrative controls • Engineering controls • Personal protective equipment
Administrative Controls One way to control worker exposure to workplace hazards is through policies and procedures. Some examples of the administrative controls used in labs are: • The SDSU CHP. • Standard Operating Procedures. • Lab-Specific SOP Training. • Chemical Labeling. • Material Safety Data Sheets. • Security Training.
Lab Security Some points to consider are: • Recognize that laboratory security is related to but different from laboratory safety and develop a site-specific security policy. • Control access to areas where hazardous materials are used and stored. • Know who is in your laboratory area. • Know what materials are being brought into your lab. • Know what materials are being removed from your lab. • Have a protocol for reporting security incidents.
Material Safety Data Sheets A Material Safety Data Sheet (MSDS) is a valuable reference. It is important to consult an MSDS before introducing a new chemical into a lab protocol or working with hazardous substances. MSDS shall be received with incoming shipments of hazardous chemicals and shall be readily accessible to lab employees. Prepared by its manufacturer, an MSDS provides information to help you understand the intrinsic hazards of the chemical including: • Physical and chemical properties • Reactivity and stability information • Physical and Health Hazards • Acute and chronic toxicity information • Permissible exposure limits • Exposure control measures • Handling and storage information • Waste disposal
Engineering Controls Engineering Controls include devices such as fume hoods, glove boxes or other enclosures that reduce exposure or remove contaminants from the work environment. Fume hoods work by moving air from the lab, into the hood, and exhausting to the outside atmosphere. Use a chemical fume hood anytime your work involves: • Toxic volatile materials (chloroform, formaldehyde) with a PEL <50 mg/kg. • Carcinogens or particularly hazardous substances. • A procedure that may create an aerosol of a toxic substance. • Reactive or explosive materials or chemicals that may spatter. • Toxic gases (NH3, CO, F).
Safe Operation of Chemical Fume Hoods To ensure that airflow is not interrupted, and that the fume hood offers as much protection as possible: • Keep sources of emission at least 6 inches inside the fume hood (behind sash). • Minimize storage of chemicals in the hood. • Avoid blocking off baffle exhausts. • Ensure that blower is working (some hoods have an on/off switch). • Work with sash at proper operating level (between your face and materials in the fume hood). NOTE:Laminar flow hoods and biosafety cabinetsdo not provide any protection from chemicals. EHS inspects fume hood performance regularly, and at times may put "Match arrows for proper ventilation" stickers on the hood. Use the hood sash at or lower than the sticker to assure that air speed is adequate.
Personal Protective Equipment (PPE) Personal protective equipment includes any devices or clothing worn by the worker to protect against the hazards in the environment. Examples are: • Lab coats, • protective gloves, • safety glasses, • goggles, • and face shields. Before Entering the Lab • Make sure that you minimize exposed skin at all times by wearing the appropriate clothing (long sleeves/pants, close toed shoes). The appropriate personal protective equipment must be used at all times in the lab when chemical, radioactive, or biohazardous materials are being handled. • It is advised to wear PPE even if not working with hazardous material, because you can be injured by someone else's accident!
Glove Selection and Use • Protective gloves are an important aspect of protection against hazardous materials. The use of protective gloves can reduce the risk of a hand injury by 40%. • It is critical that users select the correct glove material based on the chemicals used and the permeation data. • The natural rubber proteins found in latex gloves may produce an allergic reaction with sensitive individuals. Some people may develop an allergy from latex after repeated use of latex products. The use of powdered gloves may take the allergic reaction much worse because the powder becomes airborne, carrying latex proteins, which are then inhaled. To reduce the risk of latex allergy: • Substitute non-latex gloves when ever possible or use powder free, reduced protein content.
Glove Use Protective gloves must be worn when there is a potential for a hand injury or skin contact with chemicals, extreme temperatures or abrasives.All protective gloves have limitations. Chemicals will eventually permeate gloves, however they can be safely used for specific time periods when the conditions and use of the chemicals are known. Protective Glove Recommendations For prolonged chemical contact or immersion use reusable gloves: Neoprene - Recommended for corrosives (pH <2.0or >12.5), solvents and alcohols. Nitrile (Blue or green) - Recommended for non-halogenated solvents such as hexane, methanol and puncture or abrasion hazards. Nomex or Zetex - Recommended for temperature extremes such as handling cryogenic fluids like liquid nitrogen. Viton - Recommended for chlorinated and aromatic solvents such as carbon tetrachloride and benzene. Butyl - Recommended for aldehydes, ketones and esters such as acetaldehyde, formaldehyde and propanone. Limitations of reusable gloves: Reusable gloves may limit fine motor skills for specific tasks.