III. Developing Standard Operating Procedures
A dominant characteristic of the research laboratory is the presence of very many chemical substances, coupled with few closely defined routine tasks or processes. This makes the development of Standard Operating Procedures for the handling of hazardous chemicals in this environment a particularly challenging task. The EH&S Office has developed a set of guiding principles (APPENDIX A) which laboratory workers will employ to lighten the burden, and help create procedures which ensure a safe and healthful workplace for all UMB employees.
This Section is intended as a practical guide to aid you in choosing additional measures and control procedures necessary for the safe handling of hazardous chemicals in your laboratory. The basic tool provided is the Basic Standard Operating Procedure (Appendix A), a 'floor' of rules for the handling of ANY chemical in the laboratory. From your chemical inventory, we have prepared a set of Laboratory-specific Operational Material Safety Data Sheets. These contain a Primary Index which identifies potential hazards beyond those controlled by the Basic SOP, and Secondary Indices which rank the relative degree of hazard. From this information, and your estimate of potential exposure under your particular conditions of use, you should be able to quickly and effectively design a SOP for the majority of procedures in use in your laboratory, or recognize circumstances in which additional aid or information from the EH&S Office is warranted. It is not a requirement to formally document any additional procedures however, laboratory workers may often find it beneficial. If you need assistance please contact EH&S.
Standard Operating Procedures are your set of work practices, personal or removable protective devices and fixed engineering controls which are employed to minimize contact with a hazardous chemical. The selection of the most effective set depends as much on the conditions of use of the substance and the physical environment as it does on the innate toxicological properties of the chemical. Design of an effective SOP thus depends heavily on an accurate assessment of this use, and includes each of the following three steps:
A. Hazard Assessment
1. Identify the Hazardous Chemicals used
2. Characterize the nature and degree of toxicity of each chemical
B. Exposure Assessment
1. Determine the potential for and route of exposure to these chemicals
C. Design of a Control Program
1. Evaluate the effectiveness of existing engineering controls, personal protective equipment, and administrative controls (work practices) in minimizing such exposure
2. Select from the available control practices a set sufficient to achieve the desired goals (meet regulatory limits or minimize potential for injury) for each use of each hazardous chemical in the laboratory
Chemicals considered 'hazardous' under the Standard are broadly defined, and include practically anything in the laboratory. Mixtures identified by product or brand name are included, except where their use is not 'occupational'- that is, their use has a pattern and frequency similar to normal 'household' use, such as hand soap. Components of kits may also be excluded, if the kit is self-contained and presents no potential for exposure; chemicals impregnated in another material such as test-strips may also be excluded. EH&S has your current inventory, which you prepared for the hazardous waste program. On obtaining new chemicals (not in your current inventory) send name and Chemical Abstract Service Registry Number (CAS #) to the EH&S Office. The CAS # is vitally important in assigning a unique identification code to the substance, required by our computerized database. It is often listed on the container label, and nearly always listed in the Identification section of the MSDS. If you are unable to locate the number, the RTECS Accession # is the next most valuable identifier. If none of these are available, or if the product is a proprietary mixture of chemicals, include the name of the Manufacturer and the Product # if possible. We will contact the Manufacturer and obtain the necessary information, although there will be some resulting delay.
This step will be carried out for you by the EH&S Office. Your chemical inventory will be qualitatively classified and indexed with regard to specific health hazard and also reactivity/compatibility for segregation and storage. Wherever possible quantitative data on the relative degree of hazard will also be compiled and presented. A full description of the lists employed and the criteria used in extracting information from the MSDS's can be found in APPENDIX B. Criteria for Chemical Classification.
Evaluate the potential for exposure. Whatever its toxicity might be, the potential for hazard for any chemical depends on the dose received. In addition to non-application specific physical considerations such as the vapor pressure, or degree of dermal uptake, the frequency, duration and amounts used are critically important in determining the hazard potential. Additional input regarding the mechanics of use are also vital; these might include reaction temperature or pressure, possible solid or liquid aerosol formation occasioned by rapid motion, sonication, or forcing of a liquid through a narrow orifice under pressure. As these factors are specific to the procedures performed, they must be evaluated by the end user or Chemical Hygiene Officer and considered when selecting appropriate control procedures.
The Standard Operating Procedures should address the particular control procedures required for the handling of each chemical, and should establish the level of stringency required for the chemical in the particular application under consideration. To aid you in that task, the Chemical Hygiene Committee has prepared a Basic Standard Operating Procedures for the Handling of Hazardous Chemicals in the Laboratory (Appendix A). These are 'baseline' procedures for any use of any chemical in the laboratory. The Laboratory Standard requires that certain classes of chemicals be given special consideration. In addition, more precise data on the physical nature or degree of hazard exists for some chemicals, which can aid you in determining appropriate control procedures. While some of the information needed for this classification can be found in the MSDS's, additional information is required, particularly for the selection of control procedures. To aid you in this task, the EH&S Office has classified your inventory list according to the following criteria:
A. Special Carcinogens
B. Human Teratogens and Reproductive Hazards
C. Highly Toxic Substances
Defined Physical Characteristics...substances possessing physical characteristics which potentiate the hazard, and aid indetermining proper control procedures
D. Inhalation Hazards
E. Dermal Hazards
F. Corrosive / Serious Irritant
G. Specific Eye Hazard
Regulated Chemicals...substances for which exposure limit values are mandated by OSHA, or recommended by NIOSH or the ACGIH
H. STELs or Short Term Exposure Limits indicate the potential for serious injury or pathology following brief exposure to the chemical.
Possible Special Risks...substances suspected of special toxicity or posing a hazard to susceptible individuals.
J. Suspect Carcinogens
K. Suspect Teratogens and Reproductive Hazards
L. Allergens and Sensitizers
Your inventory list will be returned to you as a Primary Index, with each chemical identified by the letter designation of the relevant categories. Note that there are four basic 'sets' of categories:
Categories A, B, C require a consideration of specific control procedures with regard to Designated Areas, Containment, Waste Handling and Area Decontamination.
Categories D, E, F and G are defined by specific physical characteristics. In addition to the Basic SOP, a determination of additional control procedures relevant to the specific hazard named must be made.
The remaining categories are intended to bring your attention to Regulatory Requirements, and to Chemicals for which additional precautions MAY be advisable. While important in your determination of appropriate control procedures, they do not automatically trigger a requirement for specific hazard determination on the SOP. Some additional information is included in the above Secondary Indices. In addition we have extracted relevant information from the MSDS for each chemical listed, are providing these to you as a single-page, Operational MSDS collection on the health and physical hazards of the chemicals in your workplace. These contain:
- The Hazard Index for the chemical
- NFPA Hazard Codes
- Limit Values proposed by OSHA, NIOSH or the ACGIH
- Toxicity Data
- Identification, and quantification of the relative potency of the hazard for inhalation hazards, neurotoxins reproductive toxins and carcinogens
- Health Hazards and Symptoms of Exposure
- Physical Hazards
- Physical Appearance and Characteristics.
- Data Relevant to Safe Storage
- Chemical Reactivity Information
- Appropriate Fire Extinguisher
These should provide all the information necessary to complete the SOP. Criteria used in classification, and full explanation of the material presented on the Operational MSDS is detailed in Sections 3 and 4. Should you require additional information, contact the EH&S Office for assistance. The Primary and Secondary Indices described above are tools intended to aid you in classifying chemical hazards and determining appropriate levels of control. They are computer-generated lists, selected on narrowly-defined criteria, and are not intended to be taken as inclusive or exclusive identifiers of these hazards. The 'Operational MSDS' sheets are vital in identifying hazards which do not fall within the criteria used in preparing the indices. In addition, these sheets satisfy the mandated requirement for training in the specific health hazards, symptoms of exposure, regulatory limits, and means of detection contained in the Standard.
Any chemical which lacks a Letter Designation in all categories in the Primary Index requires no control procedures beyond those defined in the Core SOP, or suggested by information contained in the Operational MSDS.
A chemical listed "I","J","K", or "L":
A listing in any of these categories indicates that a special risk may exist, but does not indicate that a common route of exposure occurs which would permit selection of a control technique. Additional quantitative information may exist however, particularly for Categories "I" and "J", in the relevant Secondary Indices, which will permit better characterization of the hazard and selection of an appropriate level of control.
A chemical listed "A","B", or "C"
Has been classified as a 'Special Hazard' according to the Standard, either as a Carcinogen, a known Reproductive Hazard, or a substance of very high toxicity. Inclusion in this group obligates the consideration of additional control procedures, specifically:
- Designated Area. An area of the workspace which clearly posted as to the substance and hazard. All individuals accessing the area must be warned of the hazard, but no other access limitation is required, and the 'designation' may be removed when the hazard is no longer present.
- Use of Containment devices such as fume hoods or glove boxes. Contingent on the likelihood of inhalation (dust, aerosol or gas/vapor) exposure.
- Laboratory Waste. Attention should be paid to the safe storage and handling of the material prior to pickup, the waste must be clearly identified, and the EH&S Office must be notified in advance of the contents.
- Decontamination Procedures. For small quantities employed in most experiments, washdown of surfaces with detergent, followed by alcohol will be sufficient. Toweling etc. employed must be clearly labeled and disposed of as laboratory waste. For larger areas, gross contamination, and materials such as spent reagents, The EH&S Office has compiled a reference collection on decontamination procedures including the IARC Monographs on Laboratory Decontamination and Destruction of Carcinogens in Laboratory Wastes. If these techniques are to be employed, special attention should be paid to the carcinogenic potency of products of the reaction, completeness of the destruction, and reaction times. If any doubt exists as to the efficiency of the procedure, endpoints should be monitored.
None of the above need necessarily to be adopted, but rather must be considered, and the decision or level of protection required based on the conditions of use.
A chemical listed "D","E","F" or "G"
Has been classified as a specific hazard for which defined control procedures are automatically prescribed. These procedures are in addition to any procedures earlier defined, but the level of stringency is dependent on the degree of exposure expected and the toxicity of the agent. Wherever possible, additional qualitative and quantitative information has been provided in theSecondary Indices.
An automatic selection of control procedures is presented based on the classification scheme employed. This selection presumes 'normal laboratory' conditions and frequencies of use of the particular substance. There are three main components to be considered:
a. Potential source strength, a function of the amounts used.
b. Duration of individual exposures.
c. Frequency of exposures.
In keeping with the Standard, our operational definition infers that the amounts of hazardous chemicals employed at any one time are minimal, e.g. contained in typical laboratory glassware, and do not approach levels found in process chemistry.
'Typical' frequency and duration of exposure are more difficult to define, as they are more closely associated with specific procedures than with specific chemicals. Operationally we will define 'typical duration and frequency' as some combination of exposures approximating 10 hours per week; for example, 2 hours per day, 5 days per week, or 3 hours per day, 3 days per week. Note that this 'benchmark' for our selection of control procedures implies significant exposure. These levels approach typical 'industrial' or process levels, or the definition of 'Regularly Exposed' found elsewhere in the Standard.
Duration and frequency of exposure are most important when assessing the potential hazard posed by chronic health hazards-- for example Carcinogens and organ-specific or systemic toxins which result in cumulative pathologies, or poorly metabolized substances which lead to cumulative body-burdens. Brief or intermittent exposures to these agents typically present no risk. For substances regulated by OSHA or with limit values prescribed by the ACGIH or NIOSH, the relevant value is the PEL, TLV, or REL respectively, which are averaged over 8 (10 for NIOSH RELs) hours per day.
Certain chemicals, such as Serious Irritants and Narcotics, which include most of the Organic Solvents found in the laboratory, are relatively less sensitive to variations in frequency and duration in selection of control procedures. Among regulated substances these are given STEL's, or Short-Term Exposure Limits, which are time-averaged over 15 minutes. Brief exposures to these substances typically do not present a health risk, but may indicate that a 'process' is not under good control. The frequency and duration of the process may thus be a critical determinant in selection of adequate controls.
For substances which pose a more acute Health Hazard or Physical Hazard such as Corrosives, duration and frequency are NOT important in determining the level of protection. Adjustments to stringency of recommended control procedures for these agents should not be made on the basis of 'contact time' alone. For those agents which are Agency-regulated, this is reflected in Ceiling Limit Values, which are not to be exceeded at any time.