ARE CONTACT LENSES SAFE WITH SCBA?
SAFETY RESEARCH
The Federal OSHA (Occupational Safety and Health Administration) regulation [Standard 1910.134, Paragraph E(5)ii] prohibiting the wearing of contact lenses while using a respirator is being challenged by some users.
Because of a growing interest in contact lenses, OSHA asked the Safety Science Group at the Lawrence Livermore National Laboratory to determine the facts regarding the safety of wearing contacts while using a full facepiece respirator.*
We sent a survey to 9,100 firefighters and fire departments throughout the United States and Canada to determine if the wearing of contacts white using a self-contained breathing apparatus (SCBA) had caused any serious problems to warrant this strict regulation (see FIRE ENGINEERING, July 1985). Of the 1,405 questionnaires returned, 403 firefighters do wear contacts with SCBA, despite the regulation. Of these, only six responded that contact lens-related problems had caused them to remove the facepiece in an environment in which the facepiece would normally be worn. In contrast, the safety-related problems caused by eyeglasses in SCBA (which are legal) are proportionately higher. Over half of the questionnaires returned by fire officers admitted that some of their firefighters wear contacts with SCBA; however, these officers knew of only eight cases when contact lens problems had caused the facepiece to be removed when It should not have been. Our investigation has indicated that these problems were not significantly hazardous, and we believe that the use of contacts with a respirator should not be prohibited.
Following is a report presenting a numerical analysis of the survey results.
* This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract No. W7405-ENG-48.
Today, 15-million people in the United States wear contact lenses and a million more are fitted with them each year. For persons who suffer from certain conditions (such as kerataconus, monocular aphakia, bullous keratopathy, and cornea scarring), contacts provide better vision than glasses. As the popularity, of contact lenses has grown, so has concern about their safety-related aspects by agencies, organizations, and individuals responsible for occupational health and safety programs.
Dennis Hirschfelder, director of Eye Safety Programs of the National Society to Prevent Blindness, has written about the dilemma that pits occupational safety and health professionals against prescribers and fitters of contact lenses—with the worker in the middle. The dilemma: Should workers be permitted to wear contact lenses on the job? Should the lenses be prohibited in any industrial areas and, if so, which ones? The controversy smolders because of a continuing lack of hard data after 25 years of rumors and misinformation.
Hirschfelder reviewed the history of known accidents involving contact lens use in an industrial environment. No accidents have been reported which indicate that contacts should not be worn just because a worker is wearing a respirator. In fact, there is little, if any, evidence that contacts should not be worn in any industrial environment as long as standard eye protection is also worn.
However, the organizations making recommendations and regulations prefer to err on the conservative side, so we end up with a federal regulation stating that the “Wearing of contact lenses in contaminated atmospheres with a respirator should not be allowed.”
The use of extended-wear contacts by firefighters has been studied by Mark Kartchner, O.D., a practicing optometrist in Salt Lake City, UT. His study with 12 firefighters compared six weeks of wearing spectacles with six weeks of wearing contacts. The advantages and disadvantages of each while performing all routine duties was recorded daily. He found a significant decrease in vision-related problems for the firefighters once they had begun to use the contacts.
Two earlier papers discussed the protective character of contacts. J. W. Guthrie and G. F. Seitz demonstrated that, for certain liquid irritant exposures (acetic acid, n-butylamine, and acetone), eyes were more protected when wearing hard contacts than without wearing any contacts. William Dixon reviewed several cases documented in the ophthalmic literature in which hard contact lenses have protected the cornea from injury by flying splinters, metal chips, and a BB pellet.
RESEARCH QUESTIONNAIRE
To determine if firefighters who wear contacts with their self-contained breathing apparatus (SCBA) have had any significant problems, Livermore Labs circulated a questionnaire among the North American fire departments ranging in size from 2 to 3,000 members. Our questionnaire had one section to be answered only by fire officers, their key questions being:
- How many firefighters under your supervision wear SCBA while wearing contact lenses?
- How many cases of safety problems with contact lens use while wearing an SCBA has your fire department had?
- How many of these have caused the wearer to remove the SCBA facepiece in an environment in which a respirator would normally be worn?
- Do you wear corrective lenses while using an SCBA?
- Have you ever had any safety problems caused by your corrective lenses while wearing an SCBA?
- How many times have these problems caused you to remove the SCBA facepiece in an environment in which it would normally be worn?
The questionnaire contained several choices for the answers.
Another section for SCBA users included queries on both contact lenses and eyeglasses. The key questions were:
SUMMARY OF FINDINGS Fire officers’ input
Over half of the departments surveyed have some firefighters who wear contact lenses while using SCBA, 1,762 or 1.4% of the firefighters covered in this survey, an average of 1.25 per fire department.
The 1,010 fire officers who responded to this section reported no deaths or serious injuries due to a firefighter removing his facepiece because of a problem with his contact lenses. Thirty-three indicated that safety problems had occurred with contact lens use while wearing an SCBA. Of these 33, only eight remarked that these problems had caused the wearers to remove their SCBA in an environment in which it would normally have been worn.
Four responded that a lens was out of place, which can blur the vision and cause irritation.
A particle under the lens, another safety problem, can result from the SCBA having a dirty breathing hose, fittings, or facepiece. The air flow would then blow the particles around and possibly get some in the eye. (This problem can be eliminated with proper maintenance.)
Particles could also get under the contact lens if the SCBA wearer takes off his facepiece in a “safe” but smokey or fume infested area (such as the staging area). It was reported that SCBAs have been contaminated in the staging area with particles so large that they wedged the exhalation valve open. This implies lack of protection from dirt of the SCBA itself, especially the facepiece and open hose connections. One fire department replied that they change bottles in the staging area without taking off the facepiece or disconnecting the hose to eliminate this potential problem. The latter procedure is recommended in SCBA training films and by SCBA manufacturers. NOTE: If the same debris was found in the facepiece of a nonuser of contact lenses, this foreign matter would impact on the surface of the naked eye.
Drying of the eyes, or actually drying of the contact lens, was marked three times. When dry, the lenses become cloudy. This occurs even in a normal environment, and commercial eye drops will alleviate the problem.
The potential for lens drying is accelerated, however, when an SCBA is worn, since the air from the tank blows across the facepiece and past the eyes. The time for this to cause clouding of the lens or irritation of the eye varies greatly. One user reported clouding in five minutes, other users have had only one lens cloud, and many never experience clouding. From our responses, it seems also that the drying time varies with the type and make of contact lenses, the make of the mask, and whether or not a nose cup is used. Also, drying can be affected by the number of hours the lenses have been worn and the wearer’s own ability to produce tears. This drying problem is certainly not universal, as some wearers say their eyes get too wet.
Interestingly, those respondents who reported rapid drying and irritation, or too much tearing, sweating, and washing of the lens from the eye had never adapted well to daily, off-duty use of contacts. They have since quit wearing contacts.
Most of the firefighters reporting problems have been wearing contact lenses for over a year. The split between hard, soft, and extended-wear lenses is fairly even. Four of the eight officers reporting the above problems favor not allowing contact lenses, two favor contact use, and two have no opinion. To focus on the positive side of contact lens use, however, see the responses showing that a large number of firefighters prefer to wear contact lenses with SCBA and have not had any problems (see Figure 2, Question 22).
SCBA user’s input
Of the 1,357 respondents in this category, 947 wear some type of corrective lenses in their daily activities, of which 418 wear contacts. Of the 418 who wear contacts, 403 also wear contacts while wearing SCBA, despite the Occupational Safety and Health Administration (OSHA) regulation.
A striking contrast to this is that of the 529 who wear eyeglasses in their daily activities, only 81 also wear eyeglasses with an SCBA. Of the 529, a total of 97 reported that they had had safety problems caused by wearing eyeglasses with an SCBA (which is legal),.while only 34 had reported safety problems caused by wearing contact lenses. The number of eyeglassrelated problems is even greater than the number who actually wear eyeglasses with an SCBA.
Some of those who have had trouble with eyeglasses now either wear contacts or suffer from poor vision during SCBA use due to not wearing corrective lenses.
Of the 829 responses to the question “Please describe any positive or negative experiences you have had or know of involving contact lenses and SCBA use,” the great majority strongly support the use of contacts.
In our interviews with respondents, no one claimed to have had a problem so severe that he could not leave the hazardous atmosphere before adjusting the lenses. Respondents whose lenses fell away from the eye surface did not consider this a serious problem. Usually, the lenses that fall out are recovered later inside the facepiece, although one interviewee said he has lost about one lens per year for the last six years.
Most responders have had no problems. Most of those who have had problems are willing to tolerate them and prefer contacts to the alternatives, which are: not using corrective lenses and thus having impaired vision; wearing eyeglasses, which many claim will not fit in the facepiece of their SCBA and often move out of position or fog up; or cease participating in fire suppression activities.
RECOMMENDATIONS
Based on numerical analysis of the responses to the questionnaire, our follow-up interviews with those indicating the worst problems, and reading the 829 comments on positive or negative experiences with contact lenses, we believe the prohibition against wearing contact lenses while using a full facepiece respirator should be revoked or withdrawn.
Respirator users should be sure their respirators are stored and maintained in a clean environment. Keeping the full facepiece in a disposable plastic bag when not in use and capping the connection to the regulator would eliminate the problem of dirt blowing into the facepiece, and subsequently irritating the eyes of a contact lens wearer when the SCBA is first turned on.
Problems with particles and fumes in a staging area should be considered by the individual corrective lens user or by the fire department. The comments on this situation vary widely, from opinions that contacts protect the eyes, to those who believe contacts cause increased irritation. Variations in routine work procedures can also improve the use of contact lenses, such as changing air bottles without removing the facepiece, so that cinders or dust cannot fall into it.
References
D. Hirschfelder, “Contact Lenses May Pose New Problems in the Workplace,” OCCUPATIONAL HEALTH AND SAFETY, pages 54-58, March 1984.
D. Hirschfelder, “Contact Lenses in the Workplace: The Dilemma,” SIGHT SAVING, Volume 52, Issue 1, pages 14-18, 1983.
M. N. Kartchner, “Fight Fires with Contacts?” CONTACT LENS FORUM, pages 21-30, March 1985.
P. Durkin, “To See or Not to See?” THE INTERNATIONAL FIRE CHIEF, pages 25-27, May 1984.
J. W. Guthrie and G. F. Seitz, “An Investigation of the Chemical Contact Lens Problem,” JOURNAL OF OCCUPATIONAL MEDICINE, Volume 17, Issue 3, pages 163-166. March 1975.
W. S. Dixon, “Contact Lenses: Do They Belong in the Workplace?” OCCUPATIONAL HEALTH AND SAFETY, pages 36-39, May/June 1978.
The full report of these findings can be obtained for $7 per copy (microfiche $4.50) from: National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161.
Wearers of corrective lenses should have the option of wearing either contact lenses or eyeglasses with their full facepiece respirators. One must keep in mind, however, that some people do not adapt well to contact lenses. If the person cannot comfortably wear contacts in everyday, non-work situations, then he will probably not adapt well to using them with a full facepiece respirator. Also, a person’s facial shape and eyeglass prescription may be such that he cannot obtain and retain a proper alignment of his eyeglasses inside the full facepiece. In this case, he would have to wear contacts, or no corrective lenses at all.
Those firefighters who have adapted well to contact lens use in their daily activities, those fire departments subscribing to maintenance procedures which protect the SCBA from dirt, and those fire departments using recommended bottle-changing procedures in the staging area have not experienced problems with the wearing of contact lenses when using SCBA.
Similarly, those fire departments that provide spectacle kits for the proper fitting of eyeglasses into the facepiece do not have problems with the wearing of eyeglasses when using SCBA. Those firefighters who try to wear eyeglasses with standard temple bars under a full facepiece do not get an adequate seal and consequently do not have proper protection. Interviews indicate, however, that with certain combinations of facepiece and facial shape, it is not physically possible to get eyeglasses in their proper position. Dr. Kartchner also mentioned that some firefighters were unable to wear spectacles under SCBA. If contact lenses were not prohibited, there would be fewer safety problems stemming from eyeglasses and poor vision.
