of the Act states that

specifically noted because of possible ations involved in smelting ores, conhealth standards shall also be based confusion on whether it is considered version of arsenic trioxide and primary on "experience gained under this and organic or inorganic. As Allied Chemiapplication of arsenical products be inother health and safety laws." cal (Ex. 109) stated copper aceto-arcluded. Dr. Braman (Ex. 145) has demsenite is inorganic. Furthermore, as onstrated that there is a sensitive A. SCOPE AND APPLICATION: PARAGRAPHS previously noted it has been implicatmethod capable of distinguishing be- (a) AND (b) ed as a potential lymphatic cancer tween organic and inorganic arsenic. This standard applies generally to agent, which compels its inclusion in Natural background levels of arsenic this standard. all occupational exposures to inorganare in the range of approximately 0.01 ic arsenic. Some of the industries Arsine has been excluded for several to 0.04 µg/m³. The higher levels rewhere substantial exposures to inorreasons. The proposal did not include ported in smelter communities cannot ganic arsenic may occur are non-ferarsine and the rulemaking did not conbe considered natural, and are typicalrous metal smelting, glass making, and sider specifically the special provisions ly not high enough to interfere with manufacture of arsenical chemicals necessary for proper control of exposampling at a 5 µg/m³ action level. In and pesticides. There may also be exsure and regulation of arsine. Most nomost facilities it can be determined posures covered by this standard in tably, no suitable sampling technique whether workers are exposed to inorother areas and industries. Pesticide has been submitted for levels signifiganic or organic arsenicals based upon application, application of arsenical cantly lower than the present standthe chemicals present and processes preservatives to wood, use of arsenicalard of 0.05 ppm. used. In those cases where both are ly treated wood and agricultural uses NIOSH and the AFL-CIO suggested present, a determination at the enare exempted. Pursuant to section 4(b) that the final standard include arsine. forcement level can be made as to the (1) of the OSHA Act, this standard OSHA agrees that arsine has a very percentage of exposure to organic ardoes not apply where other Federal high acute toxicity. It has no practical senic, using Dr. Braman's or other agencies exercise statutory authority value and exposures occur solely as a methods. to prescribe standards regulating occuresult of accidental evolution. It would The standard excludes pesticide appational safety or health. unnecessarily delay the inorganic arplication from its scope. The EPA reg- FEDERAL REGISTER, VOL. 43, NO. 88-FRIDAY, MAY 5, 1978 RULES AND REGULATIONS 19613 ulates most pesticide applications and ic arsenic. The primary route is inha- In the absence of a demonstrated has a program to extend its regulalation. The secondary route, ingestion. safe level for a carcinogen, OSHA has tions as necessary including suitable Little is known about the absorption limited employee exposure to the protection for employees. and translocation of arsenic in the varmaximum extent feasible by the use of The manufacture of pesticides is not ious regions of the upper respiratory engineering and workpractice controls. considered pesticide application and is tract, lung and the gastrointestinal OSHA believes it is appropriate to covered by this regulation. Most agritract after inhalation and ingestion. begin some protective actions prior to cultural uses are pesticide application. Although the size of particle admitted exceeding the permissible exposure As discussed in the background secby the inhalation route is limited by limit. The action level serves such a tion of this preamble one of the major the aerodynamic principle of particle purpose. Another purpose of the uses of arsenic is to impregnate wood deposition, a similar limitation does action level is to help to relieve the so as to preserve it from rot and innot apply to arsenic that may possibly burden on employers by providing a sects. The manufacture of the preserbe ingested. Furthermore, too little is cut-off point for many of the required vative solution is covered by this reguknown about the absorption and compliance activities under the standlation as is the manufacture and fortranslocation of differently sized partiard. The standard necessarily encommulation of other pesticides. However, cles in the lung, upper respiratory passes some employers whose employ- EPA regulates the impregnation of tract, lung and gastrointestinal tract ees are exposed to levels below the the wood by the preservative as a pesto predict with confidence the final permissible exposure limits. Such emticide application. EPA is now reviewbody dose. Accordingly, OSHA beployers are required to perform initial ing the registration of arsenical prelieves it appropriate to take the most monitoring to determine the extent of servatives and has indicated that it is protective stand and provide adequate their employees' exposures to inorganconsidering new requirements for approtection from all particle sizes of ic arsenic. If, on the basis of the replication and use including suitable airborne arsenic. sults of the initial measurement, expoprotection for employees. OSHA besure is below the action level, the emlieves it advisable to avoid duplicative B. CEILING LIMIT: DELETION ployer may discontinue monitoring regulation when employees will be In contrast to the proposal, the final and most other compliance activities suitably protected, and therefore the standard does not provide for a ceiling for that employee. The action level impregnation of wood with arsenical limit to supplement the permissible concept thus provides an objective preservative is not covered by this regexposure limit. In the principally afmeans for an employer to determine ulation. EPA currently does not regulate the fected industry, copper smelting. there what further actions are required for use of preserved wood. Based on the will be brief unpredictable exposure to compliance with the standard. evidence in this record the arsenic in higher levels of arsenic as a result of The statistical basis for determining the preserved wood is bound tightly to the smelting process. OSHA believes the action level has been discussed in that engineering controls now availaconnection with several proposed the wood sugars, exhibits substantial ble would not prevent occasional ex- OSHA health standards (See, for exchemical differences from other pencursions above a ceiling limit though ample, "Proposed Standard for Trichtavalent arsenicals after reaction, and there are practices and controls availaloroethylene" (Oct. 20, 1975, 40 FR appears not to leach out in substantial amounts (Exhibits 31 C-2, 5, 6, 7, 21, ble which will reduce their frequency 49032)). In brief, although all meaand extent. surements on a given day may fall 36). Therefore OSHA does not believe it/ appropriate to regulate the use of For the permissible exposure limit of below the permissible exposure limit, 10 µg/m³ to be met, employers will some possibility exists that on unmeapreserved wood on the basis of the current record. have to implement feasible engineersured days the employee's actual expo- If further information indicates the ing and work practice controls which sure may exceed the permissible limit. need for regulation, and other agenwill tend to reduce the number and Where exposure measurements are extent of excursions over the permissiabove one-half of the permissible excies have not exercised jurisdiction, ble exposure limit. In this manner, the posure limit, i.e., the action level, the OSHA will institute proceedings to standard assures that protection will employer cannot reasonably be confisuitably regulate employee exposure to arsenically preserved wood. be provided to employees. dent that his employees may not be overexposed. (Leidel, N. A., et al., "Ex- PARTICULATE SIZE C. ACTION LEVEL: PARAGRAPH (B) posure Measurement Action Level and Occupational Environmental Variabil- The proposed standard was based on The proposal contained an action ity." DHEW, PHS, DCD, NIOSH, the regulation of worker exposure to level of 2 µg/m³ which triggered the DLCK (August 1975)). Therefore, reall particle sizes of inorganic arsenic. monitoring, medical, regulated area, quiring periodic employee exposure Some parties requested that this rehygiene facilities and protective clothmeasurements to begin at the action quirement be changed so that only aring requirements of the proposed level provides the employer with a reasenical particulates of "respirable size" standard. This requirement has been sonable degree of confidence in the re- (less than 10 micrometers mass retained in the final standard, but the sults of his measurement program. median diameter) be regulated (Exhibnumerical value has been changed to 5 However, OSHA has reduced the its 3F, 3T, 23A, 106, 108, 109). This po- µg/m³ in light of the change of the number or requirements and burden sition has been summarized by Engelpermissible exposure limit. Many industry spokepersons beof requirements triggered by the hard Minerals & Chemicals Corp. (Exhibit 3F) as follows: lieved that the action level was overly action level, while maintaining its burdensome, stating their opinion that major benefits. The action level has Since the Rule clearly refers only to arif the permissible exposure level were been raised from 2 µg/m³ to 5 µg/m³, senic exposure in terms of mg As/m3 of air a level that adequately protects workthereby reducing the number of workin the workplace, it is implicit that the Rule ers, no action level should be required ers and number of establishments reis intended to cover only airborne arsenical particulates or aerosols and should, there- (Exhibits 3A, 3W, and 112). Others bequired to do more than initial monifore, indeed be restricted to those only in lieved that it was probably impossible toring by this standard. the respirable particulate size range, i.e., to reduce employee exposures to 2 µg/ D. REGULATED AREAS AND NOTIFICATION less than approximately 10 microns e.s.d., m3 in many locations, and therefore OF USE: PARAGRAPHS (D) AND (F) since particles larger than this are non-refelt it should be deleted (Exhibits 3-L, spirable and physiologically rejected. 30, 3v). It was also pointed out that it The final standard requires that reg- There are two major routes of entry would be difficult to measure a 2 µg/ ulated areas (RA) be established and of airborne concentrations of inorgan- m3level. access limited to authorized persons. FEDERAL REGISTER, VOL. 43, NO. 88-FRIDAY, MAY 5, 1978 19614 RULES AND REGULATIONS This section is to aid in limiting expo- Paragraph (r) of the proposal re- Some industry spokespersons ex sure to inorganic arsenic. By limiting quired employers with regulated areas pressed their preference for biological access to the RA to authorized perto notify OSHA area offices. This remonitoring (urinary arsenic measuresons, the standard requires the emquirement has been retained in paraments) (Ex. 29G, Ex. 118) stating that ployer to prevent those persons who graph (d) of the final standard so that biological monitoring best defines the are not authorized to enter the RA OSHA will be aware of facilities where risk to the employee, that it is equally from doing so and thereby being exsubstantial exposure to arsenic exists. effective and much less expensive (Ex. posed to inorganic arsenic. Other pur- 3T). Some feel that this form of bioposes of this section are to designate E. EXPOSURE MONITORING AND logical monitoring can be used as an those areas in which precautionary MEASUREMENT: PARAGRAPH (E) indication of the total effectiveness of signs are posted, and to designate The standard requires each employcontrol programs, including the effecthose employees subject to quarterly er who has a place of employment tiveness of respirator usage and the exposure monitoring. Additionally, where there is exposure to inorganic personal hygiene habits of the ememployees working in regulated areas arsenic as the result of the employers' ployee (Ex. 118). ASARCO (Ex. 29G, are covered by the washing and showactivities to monitor their employees' App. 7) presented a regression analysis ering provisions and certain activities exposure to inorganic arsenic over an of urinary arsenic levels versus airsuch as smoking and eating are proeight hour period without regard to borne arsenic exposure levels. In this hibited within regulated areas. the use of respiratory protection. Secanalysis, the average individual em- The proposed standard required that tion 6(b)(7) of the Act (29 U.S.C. 655) ployee's urinary arsenic level taken on the regulated area be established at mandates that any standard promulten consecutive days were regressed on the action level. Commentors (Ex. 3B, gated under subsection 6(b) shall, the corresponding average individual 108, 112) suggested that the regulated area be established in areas in which where appropriate, provide for moniemployee airborne arsenic exposure. toring or measuring employee expo- The data on which this correlation is exposure exceeds the permissible exposure limit (sometimes refered to as sure at such locations and intervals, based is contained in Exhibit 125. the PEL or TWA limit). This suggesand in such manner as may be neces- Based on the 23 employees so meastion has been adopted for the Final sary for the protection of employees. ured, a weak to moderate linear corre- There are various reasons which lation (regression coefficient of 0.528) Standard and is consistent with the make it appropriate for employers to was observed. approach taken in other OSHA standards for carcinogens. measure employee exposure to inor- During the April 1975 hearing, The proposed standard required that ganic arsenic. First, exposure monitor- NIOSH representatives were asked to a daily roster of all persons who enter ing informs the employer whether he evaluate the urinary arsenic determithe RA be made and maintained for at is meeting his legal obligation to keep nations as an indicator of worker exleast forty years or the duration of employee exposures below the permisposure (ATR 372-6). Dr. Blejer reemployment plus 20 years whichever sible exposure limit. Second, exposure sponded: is longer (Ex. 2a, 40 FR 3397, 3400). monitoring evaluates the effectiveness From my background as a physician and The final standard does not requiare of the installation of engineering and knowledge of various plants, not smelters, that a roster be kept. work practice controls and informs the which handle inorganic arsenicals, the uri- Commentors have criticized this proemployer whether additional controls nary excretion of arsenic is an extremely vision as excessively interfering with need be instituted. Third, exposure variable and inconstant thing for any indiday to day operations (Ex. 3B). OSHA monitoring is necessary in order to devidual. has concluded that rosters would be of termine whether respiratory protec- Occupationally, I have learned and I wastion is required at all, and if so, which taught, as well, to treat results-all the relittle use in limiting worker exposure to inorganic arsenic. Other records respirator is to be selected. sults-to group them and take means or average but not on individual bases, because such as medical records and results of Fourth, section 8(c)(3) of the Act (29 of dietary and many, many other factors. exposure to monitoring required by U.S.C. 657) requires employers to Therefore, the results of an individual the standard would provide more promptly notify any employee who would not be indicative of an exposure and useful information and obviate the has been or is being exposed to toxic if they were to be enormously high, which need for a roster. materials or harmful physical agents would be about the only way that you could The proposed standard prohibited at levels which exceed those pretell that they were occupationally related, I eating, drinking and applying cosmetscribed by an applicable occupational would say, then you would be corroborating ics in areas where employees were exsafety and health standard and to what would have to be a fairly gross expoposed above the action level. The speinform such employee of the correcsure or overexposure. [ATR 3731 cific prohibition was located in the Hytive action being taken. Exposure OSHA has concluded that it is not giene paragraph of the proposal. monitoring is necessary in order to deappropriate to use urinary arsenic The limitation on eating, smoking termine whether employees are being measurements as the primary means and applying cosmetics in regulated exposed to inorganic arsenic at levels for determining employee exposure. areas is necessary to prevent the ingesexceeding that prescribed by this Airborne monitoring is effective and is tion of inorganic arsenic. As discussed standard and therefore should be noticapable of detecting levels over the elsewhere in the preamble, the ingesfied as required by the Act. Finally, permissible exposure limit before over tion of inorganic arsenic has been imthe results of exposure monitoring are exposures to employees occur. Urinary plicated as a cause of cancer. There is part of the information which it is monitoring is variable and the correlathe possibility of the translocation of necessary to supply to the physician. tion between airborne and urinary arsenic within the body after inges- The need to conduct exposure monilevels is only weak to moderate. OSHA tion. Further it is OSHA's policy to toring was generally accepted by parhas further concluded that it will not limit all routes of exposure to carcinoticipants in the rulemaking process. A require urinary arsenic determinations gens. Moreover, inorganic arsenic is a requirement that monitoring be done as a supplement to airborne monitorskin irritant. Applying cosmetics in its was included in the proposed standard. ing. However, employers may use it as presence would retain arsenic against In view of this support and for the an additional monitoring technique if the skin. reasons stated above, the standard esthey believe it useful in their particu- Drinking water is permitted within tablishes a requirement for employers lar circumstances. regulated areas. The possibility of to monitor employee exposure to inor- The requirement for airborne moniheat stress exists in smelters. Thereganic arsenic. The monitoring of airtoring is limited to employers who fore it is necessary to have water readborne exposure is consistent with the have a place of employment where inily available. proposal and other health standards. organic arsenic is released as a result FEDERAL REGISTER, VOL. 43, NO. 88-FRIDAY, MAY 5, 1978 RULES AND REGULATIONS 19615 of their operations. There are trace determine if any worker was exposed weather may raise exposure to above amounts of naturally occurring arsenic above the action level (Exhibit 2A, p. the TWA limit and to compensate for in the atmosphere (.01-.04 µg/m³) and 3400). OSHA has reconsidered this the possibility that such measurewithout this limitation, all employers provision. It is not possible by visual ments are falsely low. would be required to monitor. (For a inspection to accurately determine Periodic monitoring and measurediscussion of this limitation see the worker exposure. Accurate initial dement are not required when initial Scope and Application section.) terminations are crucial, particularly measurements are below 5 µg/m³. It is The standard requires that the meawhen dealing with a carcinogen. Acunlikely when exposures are at this surements be made by monitoring cordingly, this provision has not been level that minor fluctuations in procwhich is representative of each emincluded in the standard and the emess, materials, or weather or measureployee's exposure to inorganic arsenic ployer must monitor and measure the ment accuracy would result in false over an eight hour period without employee's actual exposures. negative readings below the TWA regard to the use of respiratory pro- The final standard requires remealimit. It would not be appropriate to tection. Exposure measurements for surement every 3 months for employrequire periodic measurements in each individual employee would, of ees exposed above the TWA limit and those operations where exposures course, be an indication of that emevery 6 months for those exposed bewould be well below the permissible ployee's exposure. However, this may tween 5 and 10 µg/m³. In addition a reexposure limit. If there is a significant be unnecessarily burdensome in some measurement is required where the change in materials or process in an instances, as some industry particiinitial measurement is below 5 µg/m³ area where exposure was under 5 µg/ pants have suggested. Monitoring if there is a significant change in proc- m3, remeasurement would be required. which is truly representative of an emess or materials which could result in The standard requires that whenployee's exposure would provide the additional exposures. ever there has been production, procnecessary information and in many in- The proposal required monthly meaess, or control change which may stances would involve fewer samples. surements for employees exposed result in new or additional exposures The employee exposure measureabove the permissible exposure (TWA) to inorganic arsenic, or whenever the ments are to be made without regard limit and bimonthly for employees exemployer has any other reason to susto the use of respiratory protection. In posed between the action level and the pect an increase in employee exposure, order to use the results of exposure TWA limit. Employers criticized these the employer shall repeat the required monitoring to evaluate the effectivefrequencies as being too burdensome monitoring and measurements for ness of the required engineering and in relation to the possible health benethose employees affected by such work practice controls, to determine fits (Ex. 3A, Ex. 3B, Ex. 118). change or increase. A redetermination whether additional controls must be There are substantial fluctuations in which was also included in the proinstituted, and to ascertain which, if exposure conditions, hour to hour and posed standard, is required in order to any, respirator must be used, it is necday to day at smelters, the largest inensure that the most recent monitoressary to know employee exposure dustry affected by this standard (Ex. ing accurately represents the existing levels without the use of respiratory 29A, Ex. 29G). The higher the meaexposure conditions. This is necessary protection. surement frequency, the higher the so that the employer may take the ap- Exposure conditions vary throughaccuracy of the employee exposure propriate actions such as instituting out the day (Exhibit 29G). At least profile. On the other hand, monthly additional engineering controls and one sample is to be taken during each or bimonthly monitoring of significant providing the appropriate respiratory shift in order to ensure that exposure numbers of employees at some smeltprotection. measurements represent exposures of ers would require major resources in-