Contraception
January 1989 Vol. 39 No. 1

Bruce Voeller
Mariposa Foundation, Topanga CA
Anne H. Coulson
UCLA School of Public Health
Gerald S. Berstein, Robert M. Nakamura
Dept. Obstetrics and Gynecology
USC School of Medicine, Los Angeles, CA

Mineral Oil Lubricants Cause Rapid Deterioration of Latex

Abstract

As little as sixty seconds' exposure of commerical latex condoms to mineral oil, a common component of hand lotions and other lubricants used during sexual intercourse, caused approximately 90% decreases in the strength of the condoms, as measured by their burst volumes in the standard ISO (International Standards Organization) Air Burst Test. Burst pressured were also reduced, although less dramatically. Lubricants such as Vaseline Intensive Care and Johnson's Baby Oil, each containing baby oil, also affected condom integrity. Five minutes exposure of condoms to glycerol, a frequent component of hand lotions and 'personal lubricants', did not significantly affect burst volume or pressure. Aqueous nonoxynol-9 spermicide did not affect either burst index.

The implications of these results for contraception and protection from sexually transmitted diseases, including AIDS, are discussed.

Introduction

Condom users have long been admonished that oil-based lubricants weaken condoms. [1] However, a literature search, as well as extensive discussion with senior researchers at British and American condom manufacturers, at the U.S. Food and Drug Administration (FDA), and at the Consumers Union, indicates that little experimental data exist to substantiate this warning.

Industrial experience — that prolonged exposure of latex goods to petroleum products causes deterioration — justifies concern about oils and condoms. But it is unclear how relevant such information is to condom use. On the one hand, condoms are thin latex films with large surface-to-volume ratios which offer ease of attack by gases, fluid agents, and deleterious wavelengths such as ultra violet. On the other hand, the duration of exposure of condoms to lubricants during sexual activity usually is rather brief comparted with most industrial exposures of latex; industrial exposure is commonly measured in days, weeks, or months. While sexual intercourse may continue for 15 minutes or longer, Kinsey et al. document that on average intercourse lasts less than two minutes. [2]

The question thus becomes, do lubricants used during intercourse interact with latex quickly enough to cause condoms to break or leak during the average duration of sexual intercourse — or even during marathon sex?

Mineral oil causes visible blisters to appear in latex condoms within three to four minutes [3], and Voeller et al. [4] reported that 15 minutes exposure of condoms to mineral oil allowed leakage of the AIDS virus, HIV-1 [12 or 23 condoms]. Fifteen minutes exposure to diverse oils recently has been reported to induce striking loss of the tensile strength in condoms. [5]

In the present study we treated latex condoms with mineral oil or other lubricants for periods ranging from 60 seconds to one hour. We measured the change in condom integrity by monitoring decreases in burst volumes and pressures in the standard ISO (International Standards Organization) Air Burst Test. While this is a quality control test of condom strength, required in many countries as a manufacturing standard, it may also predict the performance of condoms during actual use. [6,7]

Methods

Generic, non-lubricated condoms were supplied by Schmid Laboritories, Inc. These condoms were loose packed (not foil wraps) and non-rolled. Two manufacturing lots were employed, differing in age by aproximately nine months. Customary ISO Air Burst Tests were conducted utilizing purified nitrogen gas, rather than air, as the inflating gas. In the Air Burst Test, the open rim of a condom is fitted over the opening atop the Air Burst Instrument, and the condom is inflated at a standard rate of 24.5 L per minute until the condom bursts. Burst pressure us measured in kilo-Pascals (kPa) and burst volume in liters. In the present tests, the outer surfaces of eleven replicate condoms were individually wetted by immersion in a beaker of test fluid to one half of their length (measured from the closed tip of the condom). The condoms were laid out upon a filter paper for designated time intervals. Near the end of the interval, they were patted with filter paper to remove excess fluid, and tested on the Air Burst instrument for burst time, volume and pressure. Designated time periods were measured from the start of the immersion of the exposed portion of the condom, until the beginning of the inflation of the treated condom on the Air Burst Instrument. All lubricant operations were conducted at room temperature.

All tests were run with and compared with untreated controls.

Lubricant fluid tests were:

• triple gas distilled water
• mineral oil, light (E. H. Sargent & Co, Lot No. F8, Viscosity 80-90 Saybolt)
• Squibb Mineral Oil
• Johnson's Baby Oil
• vaseline Intensive Care Lotion
• glycerol [glycerin] (Mallinckrodt, analytical grade)
• an aqueous, generic spermicidal gel containing:
  
  • 1.5% hydroxyethylcellose (Union Carbide)
  • 30% glycerol (Emery Industries)
  • 1% nonoxynol-9 (GAF Corporation)

The effect of wate was tested both to see if it had an effect per se on condom strength and to evaluate whether the physical manipulations involved in lubricating the test condom affected test results.

Results

The results are presented in Table I and Fig. 1. Table I includes data from two lots of test condoms, one aproximately ten months old (from the date of manufacture) and the other aproximately one month old. Means and standard deviations (S.D.) for burst pressure and burst volume for each lot and treatment are presented. The lower limit of the ISO value (that limit below which a condom is counted as a failure) is given in the same units for comparison.

Control condoms from the two lots showed different volume values a well as different pressue values, which probably were due to the difference in age of the condoms. For example, the older condoms (Lot 1) had a mean burst volume only 58.6% that for Lot 2. Thus, for purposes of comparing the effects of lubricants between the two series of experiments, the data are presented in Fig. 1 as percentages of the relevant control values.

Preliminary mineral oil studies revealed that no significant differences existed among results from 60 minutes, 15 minutes, five minutes, and one minute exposure times. Thus the data depicted in Table I and Fig. 1 represent 60 second exposures, with the exception of Vaseline Intensive Care and glycerol, each with exposure times of five minutes.

Both types of mineral oil, and Johnson's Baby Oil, significantly reduced the burst pressure and burst volume of the condoms tested. While the means (volume and pressure) for glycerol were lower than those of the two controls, they were not significantly different. Vaseline Intensive Care Lotion significantly decreased both the burst volume and the burst pressure.

Burst pressures for the distilled water and spermicide treated condoms were not different from controls. The results with distilled water also demonstrate that the mechanics of lubricant application employed in these studies is not a significant source of the damage to the tested condoms, compared with untreated controls.

Table 1

Condom Air Burst Test Volumes and Pressures of Two Lots of Condoms (10 months and 1 month old) Treated with Lubricants for 60 Seconds or five minutes (**) - Mean ±S.D.

FIGURE 1:
Air Burst Test Results for Lubricants – % Control

Burst volumes and pressures of year-old condoms treated wth lubricants for 60 seconds. (* 5-minute exposure period.)

Condom Lot No. 1

Condom Lot No. 2

Discussion

The results presented demonstrate that mineral oil acts very rapidly to damage the latex condoms in this study. The rapidity of this dramatic effect, which occurs within 60 seconds, is an order of magnitude faster than suggested from other recent studies in which condoms were exposed to lubricants for 15 minutes or longe. [4,5] While yet briefer exposure periods will be tested, time less than 30 seconds are difficult fo measure accurately because of the several physical manipulations of the condoms required in studies such as those reported here.

Moreover, all these short-time periods are distinct from the longer term ones typically characterizing deterioration of non-film latex products. The rapid effects seen here upon condoms fall in the same time range as the duration of sexual intercourse, where condoms are commonly used with lubicants.

As noted above, Kinsey and his colleagues reported that:

"For perhaps three-quarters of all males, orgasm is reached within two minutes after the initiation of the sexual relation, and for a not inconsiderable number of males the climax may be reached within less than a minute or even within ten or twenty seconds after coital entrance." [2]

Interviews with 25 men who consistently broke latex condoms during post-penetration sexual intercourse indicated that 23 of the 25 men regularly used Johnson's Baby Oil, Vaseline Intensive Care or Nivea hand lotions to facilitate sexual intercourse. [8] Mineral oil was found to be a common component of each of the lubricants used, as well as of many others employed during sexual intercourse. Moreover, a survey of a geographically diverse sampling of 1275 American males indicated that Vaseline Intensive Care was the most frequently used sexual lubricant (61% who ever used), and the highest ranked lubricant (19%). [9] Baby oil or other oil-based lubricants also were the first choice of over half of 145 British males (83 men out of 145, or 57%). [10,11]

Johnson's Baby Oil is nearly pure mineral oil, Vaseline Intensive Care lotion contains mineral oil. The results in Fig. 1 demonstrate that Johnson's Baby Oil especially quickly affects condom strength and that Vaseline Intensive Care, while less rapidly destructive, has an effect within five minutes' exposure.

When persistent condom breakers were interviewed, it became evident that the probable source of their breakage was that they mistakenly thought lubricants such as Vaseline Intensive Care, Nivea and Johnson's Baby Oil, were water-based, because they washed off fairly readily with water, compared with Vaseline (petrolatum) or Crisco (hydrogenated vegetable oil). [8] Only the latter were perceived as proscribed oil-based lubricants.

The one generic spermicide gel which was tested caused no significant reduction in the strength of the test condoms. These results, and those from distilled water controls, add support to the belief that water-based lubricants, including spermicidal gels, are safe for use with condoms. This observation is of importance because of the increasing emphasis placed upon this surfactant's use in AIDS prevention recommendations, such as those of the Surgeon General. [12]

While further kinetic studies of the effects of a wider range of lipid and non-lipid chemicals, and of different brands of condoms, are needed, the present results demonstrate that some oils cause extremely rapid and profound damage to condoms. Use of such oils poses a clear danger to those employing condoms for contraception or the prevention or sexually transmitted diseases, including AIDS.

References

1. Consumer Reports. "Condoms: A report based on laboratory tests and on detailed questionaires filled out by nearly 1,900 readers." pp.583-588. (1979) [back]

2. Kinsey, A. C., Pomeroy, W. B., and Martin, C. E. Sexual Behavior in the Human Male. W. B. Saunders Company, Philadelphia, 1948 [back] [back 2]

3. Voeller, B. in: "Minutes of the Roundtable Meeting on New Condom Design," National Institute of Child Health and Human Development; National Institutes of Health. p. 7 (April 20, 1988) [back]

4. Voeller B., Hicks D., Coulson A. H., Berstein G. S., Nakamura R. M., Browdy B, Detels, R. "Testing HIV leakage through condoms [Abstract No. 6508, p.273]. IV International Conference on AIDS, Stockholm (1988) [back] [back 2]

5. White, N., Taylor, K., Lyszkowski, A., Tullett, J., Morris, C. "Dangers of lubricants used with condoms." Nature 335:19 (1988) [back] [back 2]

6. Free, M. J., Skiens, E. W., Morrow, M. M. "Relationship between condom strength and failure during use." Contraception 22:31-37 (1980) [back]

7. Free, M. J., Hutchings, J., Firman, L., Natakusumah, R. "An assessment of burst strength distribution data for monitoring quality of condom stocks in developing countries." Contraception 33:285-299 (1986) [back]

8. Voeller, B. unpublished. [back] [back 2] [back 3]

9. Walker & Stuman Research Inc. "The Advocate Survey." The Advocate, Los Angeles, CA, 1981 [back]

10. Sonnex, C., Howard, L. C., Samarasinghe P. L. "Sexual behaviorand condom usage by homosexual men in London" [Abstract No. WP.173]. III International Conference on AIDS. Washington, DC (1987) [back]

11. Sonnex, C. personal communication to B. Voeller. [back]

12. Koop, C. E. "Physician leadership in preventing AIDS" [editorial]. J.A.M.A 258:2111 (1987) [back]