Recommended for you
GHS implementation milestones Transport of dangerous goods Implemented For international transport of dangerous goods, see Implementation through international legal instruments, recommendations, codes and guidelines. While most infectious material will clearly fall into one of the four risk groups outlined below, in some cases the level of risk associated with the different risk factors can vary dramatically within a risk assessment. Dedicated support areas , such as anterooms including showers and "clean" and "dirty" change areas, where required are considered to be part of the containment zone, even though the "clean" change area is outside the containment barrier see Section 3. Archived from the original on 18 July In the European Commission introduced legislation which defined many health claims such as "fat free" and "high fibre" to reduce the prevalence of meaningless claims on food packaging, a move welcomed by the co-op movement.
Bulletin of the World Health Organization
Some manufacturers, such as Dorset Cereals, have reduced the recommended portion sizes for their mueslis, making it appear that sugar content is shrinking. Nestle includes the nutritional impact of adding milk to its cereal in its labelling. Despite the guidance being cut to 30g in , Which? Many supermarket products have voluntarily adopted the traffic light system, which labels foods green, amber or red, to help consumers easily identify products that have low, medium or high levels of salt, fat and sugar.
But despite its popularity with healthy-eating advocates, this traffic light system has not been adopted by some big manufacturers including Kelloggs. Nestle said it used traffic light labelling on products including cereals and gave a figure for the total sugar content.
Image copyright Getty Images It is not easy to eat healthily, but doing so is being made even harder by "misleading" food labels, according to Which?. Under EU rules it is only voluntary, so some manufacturers do not do so. Purpose of guideline This guideline provides guidance on development and submission of safe work procedures to WorkSafeBC under section 5.
Content of safe work procedures If a thorough review of alternative solvents shows that no suitable non-flammable substitute is available, the employer may use a flammable liquid as a manual cleaning solvent and must develop and implement safe work procedures that effectively control flammability and health hazards. These factors do not address all workplace hazards, and employers need to ensure that the health and safety program addresses all hazards.
The procedures need to include consideration of protection for workers of the employer as well as any other workers present at a workplace where the flammable cleaning solvent is used. Submission of safe work procedures to WorkSafeBC Written safe work procedures that document effective means to control flammability and health hazards must be submitted to WorkSafeBC before a flammable liquid is used as a manual cleaning solvent.
The work procedures should be submitted to the local WorkSafeBC office for the attention of a prevention officer. Note that the Regulation requires that workers are instructed and trained in the safe work procedures. Where practicable, the cylinder must be kept in the upright position.
As shown in the Figure below this is an overhead or "bird's eye" view , the interlock method consists of dovetailing the cylinders into a cohesive unit. This method is acceptable when cylinders are in an area shipping or receiving a large number of cylinders.
Except as otherwise determined by the Board, the employer must ensure that no worker is exposed to a substance that exceeds the ceiling limit, short-term exposure limit, or 8-hour TWA limit prescribed by ACGIH.
Purpose of this guideline This guideline provides information on the significance of exposure limits for chemical and biological substances and the sources for those limits. It includes a link to the Table of Exposure Limits for Chemical and Biological Substances established under section 5. Background information An exposure limit is a maximum allowed airborne concentration and is not intended to represent a fine line between safe and harmful conditions. In determining an exposure limit, it is not possible to take into account all factors that could influence the effect that exposure to the substance may have on an individual worker.
Therefore, for all hazardous substances, regardless of any assigned exposure limit, the guiding principle is elimination of exposure or reduction to the lowest level that is reasonably achievable below the exposure limit. Due to a wide variation in individual susceptibility, some workers may experience discomfort from some substances at concentrations at or below the exposure limit.
Others may be affected more seriously by aggravation of a pre-existing condition, or by development of an occupational disease. Furthermore, other workplace contaminants may affect an individual's response. The effects of combined chemical exposures are often unknown or poorly defined. The exposure limits adopted under section 5. Substances covered by policy set out in the Prevention Policies Policy Item: Information is also available by contacting your local WorkSafeBC office or calling or toll-free Purpose of guideline This guideline outlines the process and procedure WorkSafeBC has established for addressing responsibilities for exposure limits under the phrasing in section 5.
As a regulatory authority in B. Annual revisions procedure The procedure for the annual adoption of changes to the exposure limits is as follows:.
Note that new and revised entries of the Table of Exposure Limits are shown in green shading. Deleted entries are shown as strike-through. These highlights are maintained for a period of time so that stakeholders are made aware of the amendments.
Except as otherwise determined by the board, the employer must ensure that no worker is exposed to a substance that exceeds the ceiling limit, short-term exposure limit, or 8-hour TWA limit prescribed by ACGIH. For an 8-hour TWA, a normal 8-hour work period will generally refer to a routine shift length of no more than 8 hours, over which exposure to an air contaminant occurs.
In computing the TWA, breaks should be included if there is significant exposure during the breaks but not otherwise. For example, in the case of a routine shift length of 8 hours with an additional half-hour or three quarter-hour lunch break, the 8-hour work period is the TWA period, if there is no significant exposure over the lunch break.
If significant exposure occurs during the lunch break, then the work period should be considered more than 8 hours and the exposure reduction factors stipulated in section 5. Note that minute paid breaks such as coffee breaks should be included in the exposure period. Issued originally as G5. This might be used in situations where a substance in measured or listed in milligrams per cubic metre and the Table of Exposure Limits for Chemical and Biological Substances lists that substance in parts per million.
The numeric value of If when dealing with measurements at NTP then it is necessary to calculate the molar volume of air for a temperature and pressure other than NTP and substitute this calculation for Methods for calculating molar volumes can be found in standard occupational hygiene reference books such as those listed in OHS Guideline G5. Purpose of guideline This guideline explains that welding fumes are of variable composition and provides information on substances that may be present.
It also discusses the sources of information on welding fumes and how to determine applicable exposure limits. The term "welding" includes thermal cutting and allied processes such as brazing. Welding fume composition Establishing a worker's exposure to hazardous substances in welding fumes is not a simple matter since this depends on the material being welded as well as the process and electrodes used. Welding fumes may contain fluoride, and metals or oxides of metals such as aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, hexavalent chromium, cobalt, copper, iron, lead, manganese, nickel, silver, tin, titanium, vanadium and zinc.
Apart from welding fumes, hazardous levels of gases, including carbon monoxide, oxides of nitrogen, or ozone may also be present during welding. In addition, there may be a risk of asphyxiation when shielding gases such as argon are used, particularly in an enclosed or confined space.
Decomposition products such as phosgene can form when coatings or residues on or near the object being welded are heated. Sources of information on welding fumes To determine the potential level of exposure to welding fumes, a systematic review of the base metal, electrode, and type of process is required. The safety data sheets SDS or other applicable information sources should be used to identify hazardous ingredients and expected products of reaction and decomposition.
Information on electrodes, the metal s being welded or cut, and the specific type of welding process should also be identified. Exposure limits Once the information on possible types of exposure has been determined, the Table of Exposure Limits for Chemical and Biological Substances should be consulted for the applicable exposure limit s. The employer must comply with the exposure limit for each of the individual constituents in the welding fume. An additive exposure limit as established in section 5.
Note that sections The Table of Exceptions in Policy Item: They are included in the Table of Exposure Limits for Chemical and Biological Substances and indicated with an asterisk. For the purposes of Policy Item R5. Purpose of guideline The term "nuisance dust" has been used for years to describe a group of dusts with similar effects on people. Nuisance dusts are insoluble or poorly soluble in water and do not cause toxic effects on humans other than by inflammation of the respiratory tract or by accumulation of material in the lung lung overload.
Exposure limits for nuisance dusts involve additional terms such as "total dust," "respirable dust," and "Particles not otherwise classified PNOC. It also provides information on the exposure limits for PNOC and various nuisance dusts. In addition, the guideline provides some technical information on a relatively new term that has begun to be used to describe dusts - "inhalable" particulate. Total and respirable dusts Historically, particulates in the air have been measured as "total dust.
Dusts have also been measured as "respirable dusts," which refers to the portion of total dust that is capable of passing through the upper respiratory tract and then being deposited in the gas exchange area of the lung. Examples include aluminum oxide, calcium sulfate, cellulose, emery, gypsum and Portland cement.
These substances are flagged in the Table with an End Note N which explains that an exposure limit based on the respirable fraction also applies.
PNOC may arise in various circumstances, for example, some roadwork operations, grinding acrylics and buffing nails. The concept of "inhalable dust," which has been developed by the ACGIH, refers to dusts that can be deposited anywhere in the respiratory tract. Although it is similar to the concept of "total dust," it is considered to more accurately describe the range of particle sizes that are deposited.
Substances that have been reviewed by the ACGIH, and for which exposure limits based on "inhalable" dust have been adopted by WorkSafeBC, include magnesium oxide, molybdenum metal and insolubles , and silicon carbide non-fibrous. A number of gases and vapours, such as acetylene, argon, and nitrogen, when present in high concentrations in air, act primarily as simple asphyxiants without other significant physiological effects.
A simple asphyxiant is a substance that can displace oxygen in the air, resulting in suffocation from lack of oxygen. The ACGIH does not assign a TLV, or exposure limit, because the limiting factor is the available oxygen in air, not the toxic nature of the substance itself.
An oxygen-deficient atmosphere is defined in section 1. Oxygen-deficient atmospheres do not provide adequate warning, and most asphyxiants are odourless. Note that several of the simple asphyxiants are highly flammable and can present explosion hazards, and under section 5.
Also note that the requirements of sections 5. The following information outlines the protocol for officers in establishing compliance with this section, and is based largely on operating procedures practiced by WorkSafeBC prevention officers over the last years. These follow recognized occupational hygiene principles. For further guidance on walkthrough surveys, exposure monitoring and evaluation of the exposure monitoring program, refer to OHS Guidelines G5.
Officers will not normally perform sampling if the employer has an acceptable workplace monitoring program in place, indicating that exposures are within the applicable exposure limits. In addition, officers will normally not sample for compliance purposes during temporary or emergency conditions, where exposures may be higher than normal. Officers may elect to conduct air sampling if they suspect that a problem exists and the employer has failed to conduct an exposure assessment or has an inadequate exposure-monitoring program.
Additional circumstances under which an officer may be required to sample are outlined in OHS Guidelines G5. Typically, the officer will select the worker or workers with the highest suspected exposures and conduct sampling during worst-case scenarios, such as during periods when activities or activity levels expected to result in the highest exposure are underway.
If only one sample is collected, sampling and analytical error must be accounted for. Use the coefficient of variation specified for the sampling method and follow the confidence limit guideline as described below. Contact the Occupational Disease Prevention Services section for information regarding the coefficient of variation for the analytical method of interest. Formulae for calculating the upper and lower confidence limits can be found in standard occupational hygiene references.
An officer may elect to sample on the employer's behalf or may require the employer to conduct the sampling under the provisions of section 5. Colourimetric indicator tubes are useful for assessing worker exposure.
However, these devices are limited with regard to applicability, specificity, and accuracy. Their primary intention is for screening exposures and the user must be familiar with these critical limitations if proper judgments are to be made, particularly in the matter of assessing compliance. Code of Federal Regulations. The SEI certifies a manufacturer's indicator tube if it meets the minimum requirement set out in the standard, as follows: Adherence to a quality assurance plan is verified by testing samples obtained from the supplier.
Contact the Occupational Disease Prevention Services section for further information. Indicator tubes can be used to measure non-compliance with either short-term exposure limits or ceiling limits. Readings from a short-term indicator tube should be compared to the appropriate short-term exposure limits in the Table of Exposure Limits for Chemical and Biological Substances such as a short-term exposure limit or a ceiling limit.
They should not be compared to 8-hour TWA limits. In addition, 8-hour time-weighted averages must not be calculated from results obtained using short-term indicator tubes. Long-term indicator tubes connected to a sampling pump may be used to determine 8-hour time-weighted averages.
Hydrocarbon solvents affect the central nervous system and can cause a variety of symptoms including dizziness, drowsiness, and eye and respiratory tract irritation. Due to the complexities inherent in the use and interpretation of the Reciprocal Calculation Procedure RCP , it will usually be necessary for an occupational hygiene professional to be involved in its application.
They consist of aliphatic alkane , cycloaliphatic cycloalkane , and aromatic hydrocarbons ranging from 5 to 15 carbon atoms in each molecule. The use of the mixture formula expressed in Regulation section 5.
Because there are very many possible combinations of the various alkane, cycloalkane, and aromatic mixtures, it is necessary to calculate an exposure limit for each combination rather than list all possible calculated exposure limits in the Table of Exposure Limits for Chemical and Biological Substances.
The remainder of this guideline explains WorkSafeBC's adoption of this method and provides example calculations. This method is applicable if the toxic effects of the individual chemical components are additive e. Substances in the Table of Exposure Limits e.
The RCP does not apply to benzene, n-hexane, or methylnaphthalene, which have individual ELs significantly less than the guidance values to which they would belong and have unique toxicological properties. Whenever present in the mixture, these components should be measured individually. Guidance values have been developed by a number of researchers, groups, and regulatory authorities, based on the chemical and toxicological properties of various hydrocarbon groups e.
Substances within each Hydrocarbon Group with exposure limits that are below their group Guidance Value e. The resulting calculated EL solvmix value should follow established recommendations regarding rounding. Example The safety data sheet SDS for a solvent showed the following percentages and chemical composition:.
However, benzene must be evaluated separately at the current EL for benzene. Limitations of the reciprocal calculation procedure Care in the use of the EL solvmix should be observed where the mixture in question is known to have significant toxicokinetic interactions of components that are manifested at or below the guidance values.
The guidance values apply only to vapours and do not apply to mists or aerosols. The calculation does not apply to mixtures containing olefins or other unsaturated compounds or polycyclic aromatic hydrocarbons PAHs. Occupational exposure limits for hydrocarbon solvents. Occupational hygiene limits for hydrocarbon solvents. Annals of Occupational Hygiene A proposed methodology for setting occupational exposure limits for hydrocarbon solvents.
J of Occ and Env Hygiene 2: If a substance referred to under section 5. If the work period is more than 8 hours in a 24 hour day, the 8-hour TWA limit must be reduced by multiplying the TWA limit by the following factors:. Purpose of guideline The purpose of this guideline is to explain, and provide examples of the application of excursion limits in section 5.
Background Information Threshold Limit Values TLVs refer to airborne concentrations of chemical substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse health effects. There are three categories of TLVs: The purpose of excursion limits is to ensure workers are not exposed to excessively high short bursts of hazardous substances which could cause acute health effects.
Excursion limits are based on the premise that the maximum excursion should be related to the variability generally observed in actual industrial processes. Research has shown that if the variation of short-term exposure values is very high greater than three times the average , it is an indication that the process is not under good control.
In order to be assured of satisfactory control of the industrial process and associated exposure values, a factor of three times the TWA is used. This ensures that only a small percentage of exposure values will exceed this value. If this excursion limit is exceeded, there is a high likelihood that further control measures are required. Excursion limits apply only when neither a STEL nor ceiling value has otherwise been assigned to the substance. As per section 5. A worker exposed to a concentration of 0.
This average value is less than 0. For example, a direct reading measurement of 0. Chloroacetone has a ceiling limit of 1 ppm No TWA or STEL The principle of excursion limits does not apply in this case because there is a ceiling limit assigned for chloroacetone.
A worker is protected by setting a maximum permissible concentration in air, which must not be exceeded at any time during the work period. Ethylene Oxide has a TWA of 0. Although there is no ceiling limit for ethylene oxide, the STEL also provides significant protection against very short, momentary high bursts - these bursts must not raise the 15 minute average concentration to higher than the STEL and must be limited to no more than 4 such periods in an 8 hour work shift with at least one hour between any 2 successive 15 minute excursion periods.
For example, if a worker is exposed to airborne elemental mercury 8-hour TWA limit of 0. This worker must not be exposed to an average of more than 3 X 0. The worker must not be exposed to more than 5 X 0. Where the work period exceeds 8 hours in a hour day, the 8-hour TWA limit listed in the Table of Exposure Limits for Chemical and Biological Substances must be modified to ensure that workers on extended shifts are as equally protected as if they were working on conventional 8-hour shifts.
This section envisages several consecutive workdays with shifts longer than the normal 8-hour shift, not an occasional overtime shift. If exposure occurs as a single event lasting less than 8 hours during a work shift and there is a recovery period of at least 16 hours at work or otherwise before any further exposure, the reduction factor would not normally apply. This section applies to all exposure limits, with the exception of excursion limits section 5. For effects to be considered additive, the substances must act upon the same target organ such as the kidneys or target organ system such as the respiratory system and have similar toxicological effects.
Thus, substances with primarily acute effects would not be considered additive with substances which cause chronic effects, even if same organ or organ system was involved.
For example, although both silica and ammonia affect the lungs, they would not be considered additive because exposure to silica causes a chronic condition silicosis , while exposure to ammonia causes acute effects respiratory tract irritation.
Some examples of processes where additive effects need to be considered are welding, painting, and plastics manufacturing. Additive effects should also be taken into account for exposure to diesel exhaust. If it is not clear whether additive effects apply, one should consult an occupational hygienist. If skin absorption may contribute to the overall exposure, effective measures must be taken to limit exposure by this route.
The notation refers to the potential significant contribution to the overall exposure by skin absorption called the cutaneous route either by contact with vapours or, of probable greater significance, by direct skin contact with the substance.
This includes contact with the mucous membranes of the eyes. Specific substances vehicles in solutions or mixtures can also significantly enhance potential skin absorption. Although some substances are capable of causing irritation, dermatitis, and sensitization in workers, these properties are not considered relevant by the ACGIH when assigning a "Skin" notation. However, a dermatological condition can significantly affect the potential for skin absorption. The "Skin" notation is intended to alert the reader that air sampling alone is insufficient to quantify exposure accurately and that measures to prevent significant skin absorption should be considered.
Where a worker is or may be exposed to a hazardous substance, section 5. The program required under section 5. As provided for under section i of the Workers Compensation Act and section 3. Officers may conduct sampling to determine compliance with both sections 5. Additional circumstances where an officer may be required to conduct workplace monitoring include the following:.
An officer may encounter situations where the employer has neither conducted a walk-through survey nor performed sampling of contaminants, as required. In these circumstances, the officer may elect to either assist the employer in conducting the survey or performing the sampling as part of an inspection or require the employer to conduct the survey or perform the sampling. In deciding whether to assist the employer, the officer may consider. The manner in which compliance is assessed with each element of the program is described in detail below.
An officer encountering an employer who has not conducted a walk-through survey at a workplace where, in the officer's opinion, workers may be exposed to a harmful substance, will require the employer to conduct the walk-through survey in accordance with this section. If the employer conducts the walk-through survey and concludes that no worker may be at risk of overexposure to an airborne contaminant, and the officer accepts this conclusion as being reasonable, no further action will be necessary, unless there is a change in work conditions.
If, on the other hand, the employer finds a worker potentially at risk of overexposure to an airborne contaminant, air sampling must be considered, as required by section 5. Depending on the outcome of the sampling, further action may be required under sections 5. Normally, the employer would select one or more workers for sampling, which should be those workers who are likely to be the most heavily exposed on a given day worst case conditions. Sampling results are then compared with exposure limits in section 5.
If the assessment conducted under section 5. The officer will not normally conduct the additional monitoring. The following is an acceptable process for carrying out the additional monitoring. Officers should consider whether the employer has grouped workers with similar patterns of exposure together. Such grouping would normally be based on an examination of work processes, procedures, job descriptions, process schedules and weather conditions.
Groups of workers with similar patterns of exposure are referred to as "similarly exposed groups" or "homogeneous exposed groups". Workplace exposure monitoring and assessment must be conducted using occupational hygiene methods acceptable to the Board.
Purpose of guideline The purpose of this guideline is to provide information on the publications that detail occupational hygiene methods acceptable to WorkSafeBC. The guideline also explains how approval may be obtained to use methods that are not discussed in those publications. Acceptable occupational hygiene methods All elements of an assessment or monitoring program e. Environmental Protection Agency, such as the following:.
Occupational Exposure Sampling Strategy Manual. Cincinnati, Ohio, or later editions. Its Evaluation, Control, and Management. Recognition, Evaluation, and Control of Indoor Mold. Published online at https: Published online at http: Where a WorkSafeBC definition e. Where a section of the Regulation specifies use of specific test methodology, that section's specifications prevail e.
Before using occupational hygiene methods that are not discussed in references published by the organizations listed above or do not meet the other criteria in this guideline, the employer must obtain approval from the Prevention Practices and Quality Department of WorkSafeBC at the general number Purpose of guideline The purpose of this guideline is to discuss when an exposure control plan is required.
This includes providing specific sections under the Regulation where an exposure control plan is required. When an exposure control plan is required Section 5. The elements that must be incorporated into the exposure control plan are listed in section 5. If the employer has failed to conduct workplace monitoring under section 5. The determination of whether an exposure control plan is required will typically be made on the basis of the additional monitoring under section 5. The word "may" in clause a in section 5.
The levels of most common substances can be measured at the exposure limit. In such cases no exposure control plan is required. There are several other sections of the Regulation that require an exposure control plan. They are listed below. Sections of the Regulation requiring an exposure control plan ECP. The seven major elements that an exposure control plan must incorporate are listed in section 5.
The exposure control plan will normally be in writing so that all its elements can be recorded properly. If an exposure control plan is functioning effectively in a workplace, and the elements of the plan are not complex and require only limited record keeping, writing the plan may not be necessary. Similar considerations will determine the need for written work procedures under section 5. Additional details regarding some of the specific elements of an exposure control plan are described in the following OHS Guidelines.
When identifying and assessing risk, the requirements of sections 5. Continuous monitoring of the work area may also be required, when necessary, to ensure the continuing safety of workers. For example, section 6. For controlling risk, section 5. The degree of risk will depend on the probability, the extent, and the possible consequences of exposure an injury or disease.
Some of the factors that an employer should consider when performing a risk assessment are outlined in the table below. Purpose of guideline The purpose of this guideline is to clarify that the walk-through survey required under section 5. Hygiene facilities and decontamination procedures Section 5. Certain sections of Parts 6 and 7 may also require hygiene facilities and decontamination procedures, such as for asbestos, lead, and biological agents designated as hazardous substances in section 5.
Refer to the relevant OHS Guidelines for further assistance. A list of the sections in which an exposure control plan is called for is tabulated in OHS Guideline G5. The purpose of health monitoring is to protect workers from developing occupational disease by detecting biological indicators or adverse health effects at an early stage. Action can then be taken to prevent, reverse, reduce the severity, or arrest the progression of the adverse health effect or disease.
Biological Action Values BAV for biological indicators are established by the Board, based on current information and are reviewed periodically. For further information, consult the occupational physicians of WorkSafeBC. The results of health monitoring are also useful in evaluating the effectiveness of the exposure control plan, particularly when it cannot be evaluated by exposure monitoring alone. The skin and gut could be significant routes of exposure if the skin is in direct contact with a contaminant or if the contaminant is ingested and absorbed into the gut.
Biological monitoring of a substance, its metabolite or its biological effect can be a component of health monitoring. An appropriate biological indicator is one that can be detected before disease or an adverse health effect occurs. Preventive action can then be taken as required. Before undertaking biological monitoring, the following criteria regarding the biological test should be met.
Substances for which WorkSafeBC considers health monitoring may be appropriate include, but are not limited to. Health monitoring does not necessarily entail sophisticated testing, requiring medical or nursing personnel.
Setting up a health monitoring system should be done by an occupational health physician or nurse, although its day-to-day functioning can often be managed by a qualified person, such as an occupational hygienist or health and safety manager. For some substances, health monitoring may only require an early reporting system linked with periodic inquiries about signs and symptoms, self-checks such as examination of the skin for signs of sensitivity by a lay person such as a first aid attendant or supervisor.
When biological or biological effect monitoring is necessary, the services of appropriate medical, nursing or technical personnel may be required for ordering tests and taking samples. A physician or nurse must interpret the results. Health, biological and biological effect monitoring should only be carried out with the informed consent of the worker.
The individual should be advised of the purpose of the tests and biological samples should be analyzed only for the substances or effects for which consent has been obtained. Informed consent should ensure that the worker is made aware of any consequences that might occur if the results of the monitoring indicate that exposure should be reduced.
Personal results of health monitoring, as well as their interpretation, should be given to individual workers. Unless the worker's written informed consent for release is obtained, only categorical results such as a range of values rather than specific measurement values should be released to any person other than the individual or the worker's family physician.
Molecular methods, such as bacterial conjugation, transformation, and transduction, have been conventionally applied to introduce new genetic information into host organisms or cells for a variety of scientific or industrial purposes.
Advancements in biotechnology have resulted in newer, more efficient techniques to create genetically modified organisms GMOs by the insertion, deletion, replacement, or alteration of genes or gene segments. There are many applications that employ biotechnology, including the production of antibiotics, hormones, enzymes, and antibodies.
Modern biotechnology methods that are commonly used to create new or altered organisms are described below. Genetic material, either natural or synthetic, can be combined to construct novel rDNA. While there are numerous beneficial uses for rDNA technology, there is also the risk that this technology can be used to create new pathogenic organisms or to increase the pathogenicity of existing organisms, whether intentionally or not.
GMOs are organisms i. A GMO can be as simple as a point-mutated bacteria strain e. Viral vectors are vehicles used to deliver genetic material into host cells for subsequent gene expression. These systems have been used for both research and gene therapy applications.
Viral vector systems used for recombinant gene transfer are usually based on viruses present in the human population such as adenoviruses, herpesviruses, and retroviruses.
Genetic modifications are typically made to these vectors to improve gene delivery efficiency and to enhance their safety. Retroviral vector systems, including lentiviral vectors derived from HIV-1, are competent gene transfer vehicles that are widely used for their stable integration into the chromosomes of non-dividing and dividing cells, and for their long-term transgene expression.
Synthetic biology is a rapidly evolving interdisciplinary field of research that combines biology and engineering for the design, redesign, or fabrication of novel or existing natural biological components and systems.
Footnote 23 Synthetic biology includes, but is not limited to, the use of synthetic DNA sDNA to design and construct new biological parts, devices, or systems. Synthetic biology demonstrates how rapid advances in life sciences are opening up potentially dramatic applications in fields such as health care, agriculture, industrial chemistry, and energy production.
Footnote 24 It is expected to offer many significant and transforming products such as new and improved vaccines, medicines, diagnostic and infection surveillance tools, feed stocks, cleaner biofuels, and industrial processes.
Similar to rDNA technologies, synthetic biology also has the risk that this type of research may lead to the creation of new pathogenic organisms or increase the pathogenicity of existing organisms, whether intentionally or not.
Cell lines and cell cultures are commonly used in diagnostic, research, and industrial laboratories. Many cell lines do not inherently pose a risk to the individuals manipulating them in the laboratory ; however, they have the potential to contain pathogenic organisms such as bacteria e.
This can occur either naturally through contamination by adventitious organisms e. Cell lines available from commercial sources are generally very well-characterized and the presence of infectious contaminants is documented. Some commercially available and established cell lines and cell cultures may contain parts of human or animal pathogens as a result of a previous infection e.
Freshly prepared cell lines from a primary culture may have a higher risk of contamination, especially if the cell line was obtained from a source known to be or suspected of being infected with a pathogen. There have been documented LAIs associated with the manipulation of primary cell cultures. Footnote 25 Footnote Bacterial and fungal contamination in cell lines can be readily identified; however, viruses are not as easily identified and can pose a significant hazard.
The presence of biologically active mycoplasma products, the stability of mycoplasma antigens, and the fact that a number of mycoplasmas are zoonotic pathogens may make them an additional hazard to consider when working with cell lines.
Containment or " biocontainment " refers to the combination of physical design parameters and operational practices that protects personnel, the immediate work environment, the community , and the external environment from exposure to potentially hazardous biological material. The specific physical containment requirements and operational practice requirements for each containment level are specified in the CBS Chapters 3 and 4, respectively. This chapter describes the different containment levels, the different types of work areas that may be found in a containment zone , and guidance to assist regulated parties in identifying and accessing containment zones within their own facilities.
Note that all diagrams presented in this chapter are for illustrative purposes only and are not to scale; the optimal configuration of containment zones and sizes of rooms and doorways will vary according to facility type and program. Containment level describes the minimum physical containment and operational practices that a containment zone i.
There are four containment levels ranging from a basic laboratory for work with biological material containment level 1 [CL1] to the highly sophisticated facilities for work with the highest risk pathogens containment level 4 [CL4].
The CBS specifies the minimum specific physical containment requirements and operational practice requirements for containment level 2 CL2 , containment level 3 CL3 , and CL4 facilities that are regulated by the PHAC or the CFIA and that are authorized to handle or store human and animal pathogens or toxins.
Due to the low risk to public health and the animal population from Risk Group 1 RG1 biological material, there are no physical containment requirements or operational practice requirements for CL1 facilities. The following definitions provide a basic description of the different containment levels for activities with human or animal pathogens or toxins.
Work with RG1 biological material can be safely performed in a basic laboratory work area , large scale production area , or animal work area , often described as CL1.
CL1 incorporates features that provide the foundation for biosafety upon which the requirements for all higher level containment zones are built.
Biosafety is primarily achieved through the use of good microbiological laboratory practices in addition to basic physical containment design elements, such as handwashing sinks, that serve to protect personnel and the environment from the biological material being handled. Due to the low risk to public health and the animal population associated with RG1 biological material, there are no specific physical and operational requirements for CL1.
The general recommendations for the safe handling of RG1 biological material are described in Chapter CL2 builds upon the basic laboratory foundation established for CL1. Biosafety and biosecurity at CL2 are achieved through operational practices and a core subset of physical containment requirements that are proportional to the risks associated with the pathogens and toxins handled therein. Operational practices for CL2 include administrative controls e.
Physical containment features include facility design e. A representative diagram of two CL2 zones is provided in Figure A CL2 laboratory work area and a separate CL2 small animal containment zone SA zone are identified in this diagram; the solid red lines around the CL2 zones illustrate the containment zone perimeter discussed in Section 3. This diagram depicts some basic physical features for CL2 zones, such as doors to separate public areas from the containment zones, primary containment devices e.
Biosafety and biosecurity at CL3 are achieved through comprehensive operational practices and physical containment requirements. CL3 requires stringent facility design and engineering controls e. Additional engineering controls, such as effluent decontamination systems , may be needed in some cases e. Operational practices at CL3 build upon those required for CL2, taking into consideration the increased risks associated with the pathogen s and laboratory activities being carried out with RG3 pathogens.
The solid red line surrounding the CL3 zone illustrates the containment zone perimeter of the CL3 zone in this example. This diagram depicts some basic physical features such as a door to separate public areas from the containment zone, primary containment devices e. CL4 is the highest level of containment available. CL4 requires a highly complex facility design that is a self-contained area within a building or, when necessary, a separate building. It includes enhanced engineering controls e.
CL4 requires the maximum level of operational practices e. CL4 zones necessitate the use of positive-pressure suits for personnel or, as an alternative, the use of a Class III BSC line in a laboratory work area that meets the necessary CL4 requirements. A representative diagram of a CL4 zone where positive-pressure suits are worn including a laboratory work area, an animal room , an animal cubicle and post mortem room [PM room] is provided in Figure Features include anterooms with showers separating "clean" and "dirty" change areas, BSCs, and double-door autoclaves.
A containment zone refers to a physical area that meets the requirements for a specified containment level. This can be a single room e. Dedicated support areas , such as anterooms including showers and "clean" and "dirty" change areas, where required are considered to be part of the containment zone, even though the "clean" change area is outside the containment barrier see Section 3. A containment zone may include one or more work areas of different types i. The following different types of work areas describe, in general terms, where infectious material or toxins may be handled inside a containment zone.
Each area is a designated area within the containment zone. A laboratory work area is designed and equipped for performing in vitro activities, such as scientific research , diagnostic activities , commercial activities, or teaching, with infectious material or toxins. Samples of infectious material or toxins are handled for in vitro purposes only at volumes considered to be "laboratory scale" i.
Virus propagation in eggs can be conducted in a laboratory work area. A large scale production area is designed specifically for the production i. Activities involving volumes of toxins or the in vitro culture of pathogens on a scale of 10 litres or greater are generally considered as large scale. A vaccine production facility is an example of a large scale production area. Large scale work is further described in Chapter An animal work area is designed specifically for in vivo activities with infectious material or toxins i.
Animal work areas include spaces specifically designed to house and handle living animals, and may also have designated areas to handle and store animal carcasses, such as a PM room.
Animal containment zones describe containment zones that include multiple animal work areas i. Animal containment zones are further described in Section 3. A containment zone designed specifically for pathogen and toxin work performed in vivo i. A room designed to house animals in primary containment caging i. A room or space designed to house an animal or animals where the room itself serves as primary containment is referred to as an "animal cubicle".
In general, animal containment zones include a series of co-located animal rooms or animal cubicles, as well as anterooms, associated corridors and support rooms e. A zone where the animals are housed in primary containment caging inside animal rooms is termed a "small animal containment zone" or SA zone.
Alternatively, a zone where animals are housed in animal cubicles i. LA zones may also include specific rooms within the containment zone where animal necropsies and dissections are conducted which are termed PM rooms. Since there are numerous additional physical containment and operational practice requirements necessary for animal containment zones where the room itself provides the primary containment i. The designation as an SA zone or LA zone is dependent on the way in which the animal is housed primary containment caging versus the room providing primary containment rather than the actual physical size of the animal.
In general, large-sized animals and small-sized animals are housed in LA zones and SA zones, respectively. In some cases, however, small-sized animals can be housed in an LA zone. For example, a room where small-sized animals, such as chickens, are housed in an open space inside a room or where small-sized animals, such as rodents, are housed in open caging only intended to restrict animals to an area i. Considerations for animal work are described in more detail in Chapter It is essential to clearly identify the containment zone in order to determine compliance with respect to the corresponding requirements specified in the CBS.
For example, without first identifying the containment barrier and the containment zone perimeter, it is impossible to determine the point s of entry and exit, to identify critical doors , or designate appropriate areas to don and doff PPE.
Generally, in high containment zones i. In contrast, for CL2 zones, in particular in older buildings that have not been recently renovated or updated, the determination of the containment zone perimeter can be more flexible. Ultimately, it is the decision of the highest levels of the organization's structure e. The concepts and considerations for containment zone perimeters and containment barriers are discussed below.
The containment zone perimeter refers to the outermost physical boundary of a containment zone i. There can be flexibility in identifying the containment zone perimeter, in particular for individual containment zones at CL2, as illustrated in Figure In Figure a , several co-located laboratories are grouped into a single CL2 zone, where all the rooms as well as the adjoining corridor connecting all of the rooms would be considered equal containment level i.
In this scenario, the containment zone perimeter follows the outer wall of this wing of laboratories. In this example, the co-located office space adjacent to the autoclave room is located inside the defined containment zone and, consequently, all CL2 physical containment and operational practice requirements apply in order to demonstrate compliance within the zone.
Figure b , on the other hand, illustrates the same physical space of laboratories configured so that each room is a containment zone unto itself. In Figure b , the office space adjacent to the autoclave room is not identified as a containment zone and, therefore, is not required to meet any of the physical or operational requirements as specified in the CBS.
Another point of interest is that the freezers located in the corridor in Figure b are located outside of the containment zone and would be required to be kept locked if they contain pathogens or toxins, and in some cases secured to the wall e. In contrast, the freezers in Figure a , while in the same physical locations, are located inside the CL2 zone and do not require locks.
Figure illustrates an example of biohazard warning signage that includes all of the elements required at the point of entry to a containment zone i. Figure further illustrates the fluidity of the containment zone perimeter and the necessity to formally define the containment zone at CL2. In Figure a and b , an office space is located next to a laboratory work area, accessible only through the laboratory itself.
In Figure a , the containment zone perimeter encompasses the laboratory work area as well as the office space, including both of these rooms in the CL2 zone. In this scenario, all of the physical containment and operational practice requirements for CL2 as specified in the CBS would apply equally to the laboratory work area and the office space e. Figure b , illustrates the same physical space; however, in this case, the containment zone perimeter is defined at the door to the office space.
In this scenario, the office space is physically outside of the defined containment zone, and as such, the CBS requirements for CL2 would not be required for the office space. Lockable doors and other physical access requirements specified by the CBS for CL2 zones would need to be included at the entrance to the office and the appropriate operational practice requirements e.
In a similar manner, entry procedures and PPE requirements would have to be followed when entering the CL2 zone from the office. It is also recommended in such a scenario, that the containment zone perimeter be visually indicated on the floor by demarcating it with a coloured line e. This configuration may not be achievable in CL2 work areas where inward directional airflow IDA is provided. It is generally recommended to have floor plans of the containment zone and adjoining spaces, with the containment zone barrier and perimeter clearly marked, available to personnel.
These can serve to assist in educating personnel and other individuals on the physical layout and the operational requirements of the containment zone; for ease of reference, these could be included in the Biosafety Manual. The containment barrier, which refers to the boundary between "clean" and "dirty" areas inside a containment zone, is sometimes distinct from the containment zone perimeter. In some containment zones, most notably in high containment zones, a physical containment barrier of air is achieved through inward directional airflow IDA created by the presence of differential air pressures.
This effect creates a physical barrier of air against the release of airborne or aerosolized infectious material and toxins through the door. The containment barrier is always encountered at or inside the containment zone perimeter. In CL2 zones where inward directional airflow IDA or anterooms are not present, the containment barrier often overlaps with and corresponds to i. This is illustrated in Figure in the context of a CL3 zone.
In some containment zones, it is possible to have multiple containment barriers inside the same containment zone. For example, in a large CL3 LA zone i. This configuration helps prevent the spread of contamination from animal cubicles and PM rooms, protects against cross-contamination of experiments, and protects personnel.
In this case, personnel entering an animal cubicle from outside the containment zone would cross, at minimum, two containment barriers.
In contrast, the containment barrier of CL2 zones that do not require inward directional airflow IDA e. Unless otherwise identified, the containment barrier of most CL2 laboratory work areas would correspond to the containment zone perimeter.
An anteroom is a room or series of rooms inside the containment zone that separates "clean" areas from "dirty" areas i. The presence of an anteroom at the point of entry or exit through a containment barrier creates an added buffer space to protect the outer environment from the infectious material and toxins handled within.
Footnote 2 Footnote 3. The size and complexity of the anteroom s is dependent on the design and activities of the containment zone itself. In the most basic configuration, it can consist of a single room situated between an area free of contamination, which is not designated for activities involving infectious material or toxins e.
The anteroom s can serve as an access point into the work area for personnel, animals, material, and equipment. This single anteroom configuration may be incorporated into some CL2 zones, such as large scale production areas, SA zones, and LA zones. It should be noted, however, that not all containment zones at CL2 require an anteroom at the point of access. The CBS can be consulted to determine which work areas and containment zones require an anteroom. Separating the "clean" and "dirty" change areas in anterooms with a walk-through body shower allows personnel to shower upon exit across the containment barrier to reduce the risk of release of infectious material contaminating the skin or hair.
In CL3 zones where non-indigenous animal pathogens are not handled or stored, a local risk assessment LRA may be conducted to determine when a shower is or is not needed upon exit, based on the daily activities. For example, showers upon exit may be needed in cases where there is a risk of exposure to aerosolized or airborne pathogens e.
Showers are always required upon exit from a containment zone actively handling non-indigenous animal pathogens. Likewise, anterooms for CL4 zones where positive-pressure suits are worn can be very complex and may include not only "clean" and "dirty" change areas with a walk-through body shower, but also a suit change room which may or may not be distinct from the "dirty" change area and a chemical decontamination shower.
The location of the individual spaces within the anterooms is very important and dependent on the exit sequence required for personnel exiting the containment zone. Proper design of anterooms prevents the spread of contamination beyond the containment barrier, safeguards the individual's safety, and protects against a potential exposure to the chemical decontaminants in use.
Inward directional airflow IDA is an essential component to maintain biocontainment in containment zones where it is required CBS Matrix 3. The careful design and use of an anteroom on the containment barrier is the best way to protect the negative differential air pressures creating inward directional airflow IDA , thereby protecting the integrity of the containment barrier.
A critical door describes any door located directly on the containment barrier of a containment zone, animal cubicle, or PM room where inward directional airflow IDA is required. In order to maintain biocontainment and to prevent the reversal of inward directional airflow IDA i.
In CL3 LA zones i. In CL2 LA zones i. There may be multiple critical doors identified in a containment zone, depending on containment zone design. Figure illustrates anteroom spaces providing entry from an access corridor into a CL3 work area through a series of 3 doors, and describes the combinations of doors that, in its design, must be prevented from opening simultaneously in order to maintain the containment barrier.
The solid red lines around the CL2 and CL3 zones illustrate the individual containment zone perimeters. Grey shading indicates rooms and areas that are outside of containment e. Common basic physical features between all zones are depicted in the diagram.
These include a door to separate public, office, and administrative areas bottom left area from the containment zone; primary containment devices e. The anteroom in the CL3 SA zone includes a walk-through body shower. A common support area for freezers and storage bottom central area is also shared by the containment zones.
The perimeter of each containment zone coincides with the outermost wall or door. Doors are provided between the public, office, or administrative areas, which are outside the containment zone and have no physical containment requirements, and the corridors leading to the containment zones.
The solid red line around the CL4 zone illustrates the containment zone perimeter. The thin black arrows across each doorway and through the anterooms indicate the direction of traffic flow for entry and exit. A representative diagram of a CL4 zone is depicted. It contains a laboratory work area across the top of the image, an animal room SA zone positioned at the lower right side and an animal cubicle and PM room LA zone positioned at the lower left side of the laboratory work area.
The LA zone also contains a separate anteroom at the bottom of the diagram for the entry of animals and equipment into the zone, as well as a separate anteroom for the entry of personnel from the laboratory work area.
A gated area stall within the LA zone allows for separation of personnel and animals, and the PM room is directly accessed from the LA zone. The perimeter of the CL4 zone coincides with the outermost wall or door to the zone, and anterooms are part of the zone.
Containment zones containing laboratory work areas LWA and support rooms are shown in orange; containment barriers are illustrated by a black hatched line. Freezers for storage of pathogens and toxins are indicated by grey rectangles.
Configuration a illustrates a single CL2 suite or wing. Configuration b illustrates the same physical location where each work area is identified as a distinct CL2 zone.
Note that a common cell culture room is considered a LWA. This figure depicts a wing of separate rooms i. In Figure a , doors to the corridor limit access to the entire wing, such that the entire wing becomes a CL2 zone. In Figure b , the same physical space is depicted, but without doors to limit access to the wing corridor. In this configuration, each room i. Example of biohazard warning signage found at the points of entry to a containment zone. Biohazard warning signage must include the international biohazard warning symbol, containment level, name and telephone numbers of a contact person, and entry requirements CBS Matrix 3.
The sign may be further supplemented with additional requirements for entry, a list of relevant processes and primary containment equipment used in large scale production areas, or information on other hazards e. Representative biohazard warning signage.
This figure is an example of a biohazard warning sign. This biohazard warning sign includes the international biohazard warning symbol, containment level, name and telephone numbers of both a primary and alternate contact person, and entry requirements CBS matrix 3. The sign may be further supplemented with additional special provisions for entry, and a list of relevant processes and primary containment equipment used in large scale production areas, or information on other hazards e.
Configuration a illustrates a CL2 zone that includes both the laboratory work area and office space. Configuration b illustrates the same physical location where the office is excluded from the containment zone. This configuration requires additional elements such keeping the office door closed and following appropriate PPE protocols for entry to and exit from the office, in order to be compliant with the CBS requirements. This figure depicts the same CL2 containment zone in which an office is only accessible from the laboratory work area.
Configuration a illustrates a CL2 zone that includes both the laboratory work area and the office space. Configuration b illustrates the same physical space, but with the office excluded from the containment zone. This configuration requires additional elements such as posting biohazard signage on the office door, keeping the office door closed, and following appropriate PPE protocols for entry to and exit from the office, in order to be compliant with the CBS requirements.
The containment barrier is indicated with a black hatched line and the containment zone perimeter is shown with a solid red line. This figure depicts a CL3 SA zone.
The zone is accessed through an anteroom at the upper left, which includes a storage area, a clean change area, a walk-through body shower, and a dirty change area.
The laboratory work area, accessed from the anteroom, includes a cold storage area with freezers and liquid nitrogen, an area dedicated to paper and computer work, BSCs, and a double-door autoclave and pass-through chamber that cross the containment barrier. The animal room on the lower left side is accessed from the laboratory work area.
The containment zone perimeter coincides with the outermost walls of the zone, including the anteroom. The containment barrier coincides with the containment zone perimeter, except in the anteroom, where it coincides with the inner containment zone side wall of the clean change room and storage area, and the shower door leading to the clean change area.
The containment barrier of the containment zone is indicated with a black hatched line. The inner containment barrier animal cubicles is indicated with a blue dotted line and the containment zone perimeter by a solid red line. The figure shows a CL3 LA zone that includes a laboratory work area top , two animal cubicles lower left , and a PM room lower centre. The containment zone is accessed through an anteroom at the top left with a clean change area, a walk-through body shower, and a dirty change area, that leads to the laboratory work area.
Each cubicle and the PM room can be accessed from the laboratory work area through their own anterooms, which include a clean change area, a walk-through body shower, and a dirty change area. The animal cubicles and PM room can also be accessed through the dirty corridor bottom of image , which is accessed through another anteroom from the laboratory work area.
The bottom right corner also has an anteroom leading from outside the zone into the dirty corridor for animal entry. The containment zone perimeter coincides with the outermost walls of the entire zone, including anterooms leading into the zone. The containment barrier of the containment zone coincides with the perimeter, except in the anteroom where it coincides with the inner containment zone side wall of the clean change area and storage area, and the shower door leading into the clean change area.
An additional inner containment barrier exists that surrounds the dirty corridor, the outside of the animal entry anteroom, the animal cubicles and the PM room, and the anterooms to the animal areas, except in the anterooms where it coincides with the inner cubicle, PM room, or dirty corridor side wall of the clean change area, and the shower door leading into the clean change area.
The containment barrier is indicated by the black hatched line and the containment zone perimeter is shown with a solid red line. Door "A" leads to the "clean" change area of the anteroom from outside the containment zone.
Door "B", identified in yellow, is the critical door that separates the "clean" and "dirty" change areas. The "X" indicates the location of a walk-through body shower in the "dirty" change area. Door "C" leads to the CL3 work area i.