9.0 Particularly Hazardous Substances
The OSHA Laboratory Standard requires as part of the Chemical Hygiene Plan that provisions for additional employee protection be included for work involving particularly hazardous substances. These substances include “select carcinogens”, reproductive toxins, and substances which have a high degree of acute toxicity. Each of these categories will be discussed in detail in later sections.
The OSHA Laboratory Standard states for work involving particularly hazardous substances, specific consideration be given to the following provisions where appropriate:
- Establishment of a designated area.
- Use of containment devices such as fume hoods or glove boxes.
- Procedures for safe removal of contaminated waste.
- Decontamination procedures.
EHS can assist researchers by providing information on working with particularly hazardous substances. General guidelines and recommendations for the safe handling, use, and control of hazardous chemicals and particularly hazardous substances can be found in SDSs
9.1 Establishment of a Designated Area (Top)
For work involving particularly hazardous substances, laboratories should establish a designated area where particularly hazardous substances can only be used. In some cases, a designated area could be an entire room out of a suite of rooms, or could mean one particular fume hood within a laboratory. The idea is to designate one area that everyone in the laboratory is aware of where the particularly hazardous substances can only be used.
In certain cases of establishing designated areas, Principal Investigators and laboratory supervisors may want to restrict use of a particularly hazardous substance to a fume hood, glove box or other containment device. This information should be included as part of the laboratory’s SOPs and covered during in-lab training.
Establishing a designated area not only provides better employee protection, but can help minimize the area where potential contamination of particularly hazardous substances could occur. If a designated area is established, a sign should be hung up (on a fume hood for example) indicating the area is designated for use with particularly hazardous substances. Most designated areas will have special PPE requirements and/or special waste and spill cleanup procedures as well. These and other special precautions should be included within the lab’s SOPs.
9.2 Safe Removal of Contaminated Materials and Waste (Top)
Some particularly hazardous substances may require special procedures for safe disposal of both waste and/or contaminated materials. When in doubt, contact EHS at askEHS to determine proper disposal procedures. Once these disposal procedures have been identified, they should be included as part of the laboratory’s SOPs and everyone working in the lab should be trained on those procedures.
9.3 Decontamination Procedures (Top)
Some particularly hazardous substances may require special decontamination or deactivation procedures (such as Diaminobenzidine waste or Ethidium bromide) for safe handling. Review SDSs and other reference materials when working with particularly hazardous substances to identify is special decontamination procedures are required. If they are required, then this information should be included in the laboratory’s SOPs and appropriate training needs to be provided to laboratory personnel who work with these chemicals.
9.4 Guidelines for Working with Particularly Hazardous Substances (Top)
Laboratory staff should always practice good housekeeping, use engineering controls, wear proper PPE, develop and follow SOPs, and receive appropriate training when working with any chemicals. The following special guidelines should be adhered to when working with particularly hazardous substances:
- Substitute less hazardous chemicals if possible to avoid working with particularly hazardous substances and keep exposures to a minimum.
- Always obtain prior approval from the Principal Investigator before ordering any particularly hazardous substances.
- Plan your experiment out in advance, including layout of apparatus and chemical and waste containers that are necessary.
- Before working with any particularly hazardous substance, review chemical resources for any special decontamination/deactivation procedures and ensure you have the appropriate spill cleanup materials and absorbent on hand.
- Always use the minimum quantities of chemicals necessary for the experiment. If possible, try adding buffer directly to the original container and making dilutions directly.
- If possible, purchase premade solutions to avoid handling powders. If you have to use powders, it is best to weigh them in a fume hood. If it is necessary to weigh outside of a fume hood (because some particles may be too light and would pose more of a hazard due to turbulent airflow) then wear a dust mask when weighing the chemical. It is advisable to surround the weighing area with wetted paper towels to facilitate cleanup.
- As a measure of coworker protection when weighing out dusty materials or powders, consider waiting until other coworkers have left the room to prevent possible exposure and thoroughly clean up and decontaminate working surfaces.
- Whenever possible, use secondary containment, such as trays, to conduct your experiment in and for storage of particularly hazardous substances.
- Particularly hazardous substances should be stored by themselves in clearly marked trays or containers indicating what the hazard is i.e. “Carcinogens,” Reproductive Toxins”, etc.
- Always practice good personal hygiene, especially frequent hand washing, even if wearing gloves.
- If it is necessary to use a vacuum for cleaning particularly hazardous substances, only High Efficiency Particulate Air (HEPA) filters are recommended for best capture and protection. Be aware that after cleaning up chemical powders, the vacuum bag and its contents may have to be disposed of as hazardous waste.
- Ensure information related to the experiment is included within any SOPs.
9.5 Prior Approval (Top)
The OSHA Laboratory Standard requires Chemical Hygiene Plans to include information on “the circumstances under which a particular laboratory operation, procedure or activity shall require prior approval”, including “provisions for additional employee protection for work with particularly hazardous substances” such as "select carcinogens," reproductive toxins, and substances which have a high degree of acute toxicity.
Prior approval ensures that laboratory workers have received the proper training on the hazards of particularly hazardous substances or with new equipment, and that safety considerations have been taken into account BEFORE a new experiment begins.
While EHS can provide assistance in identifying circumstances when there should be prior approval before implementation of a particular laboratory operation, the ultimate responsibility of establishing prior approval procedures lies with the Principal Investigator or laboratory supervisor.
Principal Investigators or laboratory supervisors must identify operations or experiments that involve particularly hazardous substances (such as "select carcinogens," reproductive toxins, and substances which have a high degree of acute toxicity) and highly hazardous operations or equipment that require prior approval. They must establish the guidelines, procedures, and approval process that would be required. This information should be documented in the laboratory's or department's SOPs. Additionally, Principal Investigators and laboratory supervisors are strongly encouraged to have written documentation, such as “Prior Approval” forms that are completed and signed by the laboratory worker, and signed off by the Principal Investigator or laboratory supervisor and kept on file.
Examples where Principal Investigators or laboratory supervisors should consider requiring their laboratory workers to obtain prior approval include:
- Experiments that require the use of particularly hazardous substances such as "select carcinogens," reproductive toxins, and substances that have a high degree of acute toxicity, highly toxic gases, cryogenic materials and other highly hazardous chemicals or experiments involving radioactive materials, high powered lasers, etc.
- Where a significant change is planned for the amount of chemicals to be used for a routine experiment such as an increase of 10% or greater in the quantity of chemicals normally used.
- When a new piece of equipment is brought into the lab that requires special training in addition to the normal training provided to laboratory workers.
- When a laboratory worker is planning on working alone on an experiment that involves highly hazardous chemicals or operations.
9.6 Campus Prior Approval (Top)
There are some circumstances where prior approval from a campus research related committee is required before beginning an operation or activity. These include:
Additional information can be obtained from the Office of Research and Integrity Assurance webpage for Compliance with Government Regulations.
9.7 Select Carcinogens (Top)
A carcinogen is any substance or agent that is capable of causing cancer – the abnormal or uncontrolled growth of new cells in any part of the body in humans or animals. Most carcinogens are chronic toxins with long latency periods that can cause damage after repeated or long duration exposures and often do not have immediate apparent harmful effects.
The OSHA Lab Standard defines a “select carcinogen” as any substance which meets one of the following criteria:
(i) It is regulated by OSHA as a carcinogen; or
(ii) It is listed under the category, "known to be carcinogens," in the Annual Report on Carcinogens published by the National Toxicology Program (NTP) (latest edition); or
(iii) It is listed under Group 1 ("carcinogenic to humans") by the International Agency for Research on Cancer Monographs (IARC) (latest editions); or
(iv) It is listed in either Group 2A or 2B by IARC or under the category, "reasonably anticipated to be carcinogens" by NTP, and causes statistically significant tumor incidence in experimental animals in accordance with any of the following criteria:
- (A) After inhalation exposure of 6-7 hours per day, 5 days per week, for a significant portion of a lifetime to dosages of less than 10 mg/m(3);
- (B) After repeated skin application of less than 300 (mg/kg of body weight) per week; or
- (C) After oral dosages of less than 50 mg/kg of body weight per day.
With regard to mixtures, OSHA requires that a mixture “shall be assumed to present a carcinogenic hazard if it contains a component in concentrations of 0.1% or greater, which is considered to be carcinogenic.” When working with carcinogens, laboratory staff should adhere to Guidelines for Working with Particularly Hazardous Substances.
Note that the potential for carcinogens to result in cancer can also be dependent on other “lifestyle” factors such as:
- Cigarette smoking
- Alcohol consumption
- Consumption of high fat diet
- Geographic location – industrial areas and UV light exposure
- Therapeutic drugs
- Inherited conditions
More information on carcinogens, including numerous useful web links such as a listing of OSHA regulated carcinogens, can be found on the OSHA Safety and Health Topics for Carcinogens webpage. The State of California has developed an extensive list of “Carcinogens Known to the State of California through Prop 65”. Please note, this list is being provided as supplemental information to the OSHA, NTP and IARC chemical lists and is not legally mandated by New York State.
9.8 Reproductive Toxins (Top)
A reproductive toxin is a substance or agent that can cause adverse effects on the reproductive system. The toxic effects may include alterations to the reproductive organs and/or to the endocrine system (which includes the thyroid and adrenal glands). These effects can occur in both men and women.
It is important to know what chemicals that are utilized in various processes. A number of reproductive toxins are chronic toxins that cause damage after repeated or long duration exposures and can have long latency periods. Women of childbearing potential and persons planning families should be especially careful when handling reproductive toxins. Pregnant women and persons intending to start families should seek the advice of their physician before working with known or suspected reproductive toxins.
EHS offers consultation services for personnel with concerns associated with their workspace, procedures and PPE associated with working with the reproductive toxins. This is free and confidential, for more information please see: https://sp.ehs.cornell.edu/osh/occupational-health/reproductive-health/Pages/default.aspx
The following precautions should be taken when working with potentially toxic materials:
- Wear proper protective equipment including gloves, goggles and a lab coat that covers street clothes
- Gloves should be selected based on the properties of the chemicals in use
- Do not eat, drink, chew gum or apply cosmetics in the area toxic chemicals are being used
- Keep accurate records of amounts of these substances used
- Have a plan, proper equipment and materials ready to minimize exposure if an accident is to occur
- Procedure should be done with the minimum amount of material needed to complete the task
- All procedures should take place in a "controlled area" that is clearly labeled with a warning and restrictive access sign
- Whenever possible, fume hoods, glove boxes and isolation cabinets should be used, if these are not feasible, proper respiratory protection must be worn
- All work surfaces should be easily cleanable and covered in an impervious or disposable material
- Wash hands, arms and decontaminate work surface and equipment thoroughly when done with the procedure
- Protective apparel worn while working with toxic materials should not be worn outside the laboratory
- Ensure that containers of contaminated waste are transferred from controlled area in a secondary container to avoid further contamination
- Obtain SDS and procedure information for medical provider if they have any questions.
9.9 Acute Toxins (Top)
OSHA defines a chemical as being highly toxic if it falls within any of the following categories:
- (a) A chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.
- (b) A chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.
- (c) A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.
Information on determining whether or not a chemical meets one of these definitions can be found in SDSs
and other chemical references
As with any particularly hazardous substance, work involving the use of acute toxins should adhere to the Guidelines for Working with Particularly Hazardous Substances. In addition to following the Guidelines for Working with Particularly Hazardous Substances, additional guidelines for working with acute toxins include:
- Consider storing highly toxic materials in a locked storage cabinet.
- Be aware of any special antidotes that may be required in case of accidental exposure (Hydrofluoric acid and inorganic cyanides for example).
- Give particular attention to the selection of gloves and other personal protective equipment.
- Do not work with highly toxic chemicals outside of a fume hood, glove box or ventilated enclosure.
Please note, in addition to the OSHA definition, Cornell University has a Poison Inhalation Hazard Purchasing Policy – Requisitioning Procedure No. 228.