Health Hazard Alert – Benzidine, o-Tolidine and o-Dianisidine Based Dyes

Recent data from animal tests, case reports, and other sources about the carcinogenic effects and metabolism of benzidine-, o-tolidine-, and o- dianisidine-based dyes have come to the attention of OSHA and NIOSH. Both agencies have reviewed the data and conclude that the findings establish the potential of these dyes to cause cancer in humans.

OSHA and NIOSH conclude that persons working with these dyes should be aware of the potential health hazards that could result from excessive exposure to them. The intent of this document is to summarize the information available of the carcinogenic effects and metabolism of benzidine-, o-tolidine-, and o- dianisidine-based dyes and to provide guidance so that employers, employees, and physicians may work together to reduce potential health hazards that could result from excessive exposure to these dyes.

[signature]
Eula Bingham, Ph.D.
Assistant Secretary Occupational Safety and Health Administration

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Anthony Robbins, M.D.
Director National Institute for Occupational Safety and Health

Acknowledgments

The Directorate of Technical Support of the Occupational Safety and Health Administration (OSHA) and the Division of Criteria Documentation and Standards Development of the National Institute for Occupational Safety and Health (NIOSH) had primary responsibility for this document. Dr. James R. Beall of the Directorate of Technical Support. OSHA, served as the project manager. Personnel from OSHA who assisted with the development of the document include: Victor Alexander, M.D., Thomas Markham, M.D., Ching Bien, Patricia Marlow, Ph.D., Abbie Gerber, M.S. and Peter Infante, Dr. P.H. Personnel from NIOSH who assisted with development of the document include: Irwin Baumel, Ph.D., Frank Mackison, Arthur Gregory, Ph.D., and Imogene Sevin, Ph.D.

Edited by: R. Hays Bell, Ph.D. Patricia Breslin, Ph.D. Richard Lemen

Summary

OSHA and NIOSH have reviewed the literature on benzidine-based dyes. Available studies indicate that some benzidine-based dyes cause cancer in experimental animals and are converted in animals and humans to benzidine. From the accumulated evidence, OSHA and NIOSH conclude that benzidine-based dyes are potential human carcinogens. In a Special Hazard Review, NIOSH has recommended that the commercial use of benzidine-based dyes be discontinued and appropriate substitutes be utilized. OSHA has concluded that exposure of workers to the dyes should be reduced to the lowest feasible levels. This should include discontinuing use of the dyes where possible.

There is evidence from animal studies that o-tolidine, o-dianisidine, and the two dyes based on o-tolidine are carcinogenic. There is preliminary evidence that dyes based on o-tolidine and o-dianisidine, except for metalized dyes based on o-dianisidine, may be metabolically converted to the parent compounds. Benzidine-based dyes may contain residual amounts of benzidine as well as other substances such as 4-aminobiphenyl, an OSHA-regulated carcinogen. Dyes manufactured from o-dianisidine and o-tolidine may also contain residual amounts of the respective parent compounds. Therefore, there may be a problem of contamination with carcinogenic materials in addition to concern for the metabolism of these dyes to carcinogenic substances. Dyes derived from o-tolidine and o-dianisidine should be handled with great care in the workplace, and exposure to them should be strictly limited. This Health Hazard Alert summarizes these biological effects and presents actions that should be taken to reduce worker exposure to these substances.

Background

Benzidine-based dyes are defined as dyes that contain benzidine attached to other substituents by diazo linkages. Dyes based on o-tolidine contain o-tolidine (3,3′-dimethylbenzidine) attached to other substituents by diazo linkages. Dyes based on o-dianisidine (3,3′-dimethoxybenzidine) contain o-dianisidine attached to other substituents by diazo linkages. At least 16 benzidine-based, 8 o- tolidine-based, and 9 o-dianisidine-based dyes are produced currently in the United States. (1) The appendices contain a list of the dyes and a summary of major producers and importers of the dyes.

Estimates of the production and importation of these dyes by major companies are shown in Table 1. These estimates do not include importation or production by at least seven other companies.

Table 1: 1978 Production and Importation of Dyes Made From Benzidine, o-Tolidine, and o-Dianisidine

Source: Written communication from Dyes Environmental and Toxicology Organization, Inc. (DETO), Scarsdale, New York, September 24, 1979.

Thousands of workers involved in the production of dyes, textile, paper, and leather goods potentially are exposed to dyes based on benzidine, o-tolidine, and o-dianisidine. Because more than one of these dyes may be found concurrently in the same industry, it is difficult to count exposed workers and to define the extent of exposure to any specific dye.

The textile dyeing and finishing industry employed an estimated 75,400 production workers in July 1979; of these, about 7% were potentially exposed to these dyes. (2,3) In July 1979, the leather tanning and finishing industry employed 19,800 production workers of which 1,000 spray machine operators or colorers had the opportunity for exposure to the dyes. (3,4) NIOSH has estimated that about 79,200 workers in 63 occupations potentially are exposed to benzidine-based dyes. (5) The number of directly exposed workers is estimated by DETO to be less than 20,000. (6) Exposure to these compounds may occur by inhalation, ingestion, and skin absorption. (7,8,9) Definitive studies establishing the primary route of exposure have not been carried out.

Many of these dyes are complex mixtures, difficult to analyze, and may contain impurities that are carcinogenic. (10) For example, 4-aminobiphenyl, an OSHA- regulated carcinogen, and 2,4-diaminoazobenzene, an International Agency for Research on Cancer (IARC) documented carcinogen, (11) were found as impurities in a batch of C.I. Direct Black 38. (12) [See Note 1]

Benzidine-Based Dyes

Evidence of Carcinogenicity

In 1978, the National Cancer Institute (NCI) published the results of a 13-week subchronic feeding study of C.I. Direct Blue 6, C.I. Direct Black 38 and C.I. Direct Brown 95. (13,14) Two of these benzidine-based dyes induced both hepatic neoplastic nodules and hepatocellular carcinomas in male and female Fischer 344 rats; C.I. Direct Brown 95 induced tumors in female rats. (13,14) All of these dyes induced tumors within 5 weeks of the initial exposure. This is reported to be the shortest latency period for tumor development of any chemical studied in the NCI bioassay program. (5) Tumors did not develop in the control animals.

Korosteleleva et al. studied the effects of benzidine-based dyes fed to rats and mice. (15) Violet C 100% [See Note 2] a dye with a benzidine group in the molecule, induced microcholangiomas of the liver and other rare tumors in male rats; spontaneous tumors of this type were not observed in untreated rats.

Okajima et al. administered Direct Deep Black EX (C.I. Direct Black 38) in drinking water to male Wistar strain rats. This benzidine-based dye induced papillomas and carcinomas in the urinary bladder and carcinomas in the urinary bladder and carcinomas in the liver and colon. These lesions did not occur in control rats. (16)

An epidemiologic study by Yoshida et al. reported an association between employment in the dye industry and urinary bladder cancer in humans. Their review of the work histories of 200 male patients with bladder cancer revealed that 8.5% had worked in the dye industry and had been exposed to benzidine-based dyes. A review of the work histories of the 148 persons in the control group (randomly selected patients with urinary disease other than cancer) revealed that 1.4% had worked in dye industries. (17)

Metabolism of Benzidine-Based Dyes to Benzidine

Evidence exists to indicate that benzidine-based dyes are converted to the carcinogen benzidine in laboratory animals and in humans. (10) The NCI bioassay of C.I. Direct Blue 6, C.I. Direct Black 38, and C.I. Direct Brown 95 for carcinogenicity included analyses of urine samples for benzidine from treated animals. (14) Urine samples from Fischer 344 rats were collected over 24-hour periods during weeks 4 and 12. Benzidine was detected in the urine of rats given benzidine-based dyes but not in the urine of the untreated control rats. As the amount of the dye fed to the rats increased, so did the amount of benzidine excreted in the urine. Analyses of the dyes prior to mixing in feed demonstrated no residual or contaminating benzidine. The data indicate that the benzidine in the urine resulted from the bio-transformation of the dyes. Similar results were found by analyses of urine from B₆C₃F₁ mice. (14)

Rinde and Troll studied the metabolism of the benzidine-based dyes C.I. Direct Blue 6, C.I. Direct Black 38, C.lI. Direct Brown 95, and C.I. Direct Red 28 in Rhesus monkeys. (18) Each monkey was gavaged with a single dose of one dye dissolved in dimethyl sulfoxide. Each of the dyes was administered in two different dose levels in separate experiments, except for C.I. Direct Red 28, which was given at only one level. Purified benzidine was administered at two levels in the same manner. Urine was collected over a 72-hour period from all the animals and pooled for assay. Urine collected from the monkeys before dosing was used to establish the control values. The authors found benzidine and a metabolite, monoacetyl benzidine, in the urine of the monkeys receiving the dyes. The control values were negative. They concluded that the dyes were converted to benzidine in vivo. (18) Korosteleva et al. found benzidine in the blood serum and tissues of rats fed Direct Red 13. (15) This indicated that the dye had been converted to benzidine.

Lynn et al. reported on the metabolism of the benzidine-based dyes C.I. Direct Blue 2, C.I. Direct Black 4, C.I. Direct Brown 2, C.I. Direct Orange 1. C.I. Direct Red 28, C.I. Direct Orange 8, and C.I. Direct Green 1 in female mongrel dogs and rats. (19) Each of five mongrel dogs was administered a dye orally and urine was collected at 24 hour intervals for 3 days. No trace of benzidine was detected in the dogs’ urine 3 days after exposure. Some dogs were used more than once with a minimum of 1 week between dye exposures. Benzidine was recovered in the urine of each treated dog following the oral administration of the 7 dyes. Although some residual benzidine in each of the dyes had been detected prior to administration according to the authors, the amount of benzidine recovered in the urine exceeded that administered as a contaminant by at least 9 times. These finding suggest the dye was converted to benzidine in the dog.

These same dyes were administered orally to two rats for 10 days. The urinary concentration of benzidine was not sufficient to permit chromatographic quantification but a benzidine metabolite, N-acetyl benzidine, was present in the urine of the rats following the administration of the dyes. This indicates that the dyes had been bio-converted to benzidine.

Genin administered subcutaneously or orally Direct Black 3 [See Note 3] and Direct Diazo Black C (C.I. Direct Blue 2) to albino rats. (20) Urine samples contained a metabolic product that the author identified as benzidine.

Yoshida and Miyakawa injected 4 benzidine-based dyes into sections of ligated intestines of rats and mice and incubated the preparations in vitro. (21) The dyes (C.I. Direct Black 38, C.I. Direct Green 1, C.I. Direct Red 17 and C.I. Direct Red 28) were free of residual benzidine prior to injection. Subsequent analyses indicated that the 4 dyes had been converted to benzidine.

There is evidence that humans metabolize certain benzidine-based dyes to benzidine. Korosteleva et al. obtained samples of blood serum from 101 female textile workers in the dye, printing, warehouse, and color room shops. (22) Analysis revealed benzidine in the blood or workers exposed to the dyes. Genin reported that benzidine was detected in the urine of 8 of 22 workers who dried and ground the benzidine-based dyes Direct Black 3 and C.I. Direct Blue 2. (20)

Boeniger surveyed workers at facilities that manufacture or use benzidine-based dyes including paper, textile, leather, and dye manufacturing facilities. (10) At one plant manufacturing benzidine-based dyes, 2 of 8 workers potentially exposed to these dyes excreted monoacetyl benzidine in their urine. At a second dye manufacturing facility, 4 workers provided urine samples; all 4 samples contained benzidine and 3 contained monoacetyl benzidine. Three of 7 workers at a textile dyeing and finishing facility also had benzidine and monoacetyl benzidine in their urine.

o-TOLIDINE and o-TOLIDINE-BASED DYES

Evidence of Carcinogenicity

The potential of o-tolidine to cause tumors has been recognized for several years. (23) Early experiments demonstrated its ability to induce tumors in Zymbal’s gland (the specialized sebaceous gland of the auditory canal). (23) Subsequent experiments have shown that o-tolidine has the potential to induce tumors in a variety of organs and tissues. (24-28)

Perhaps the experiments by Pliss and Zabezhinsky reveal its carcinogenic potential most vividly. (25,26,27) These investigators demonstrated in a series of experiments that injections of o-tolidine in rats caused tumors in Zymbal’s gland, mammary gland, skin, lung, thyroid, stomach, small intestine, hematopoietic tissue, uterus, and preputial gland. IARC reviewed the literature on o-tolidine and concluded that it was a systemic carcinogen in rats when given subcutaneously. (29)

Two o-tolidine-based dyes, trypan blue and Evans blue, were found to be carcinogenic in rats by two independent investigators. (30,31) During an 8-month study by Marshall, these two dyes were injected subcutaneously (trypan blue) and intraperitoneally (Evans blue) into rats. (30) Two different samples of the trypan blue were used in the study; one was 80% pure ant the other was 34% pure. The rest of each sample consisted of inorganic salts and probably o-tolidine. Histiocytic tumors of the liver were found in 9 of 45 animals injected with trypan blue and in 10 of 40 rats receiving Evans blue. Reticular cell sarcomas of the lymph nodes and lymphosarcomas developed in treated animals. None of the tumors occurred at the injection sites; no tumors occurred in the two control groups of 20 animals.

Gillman and Gillman injected trypan blue into male and female rats (strain unspecified). (31) The rats were killed between days 70 and 100 and the lymph nodes were examined microscopically. Lymph nodes from control rats were used as a basis for anatomical comparison. Their study revealed that a wide variety of tumors developed in rats given trypan blue; the most common tumor was the histiocytoma.

IARC concluded that trypan blue is carcinogenic in rats when injected either intraperitoneally or subcutaneously. (11) IARC also stated that Evans blue is carcinogenic in rats when injected intraperitoneally.

Metabolism of o-Tolidine-Based Dyes to o-Tolidine

There is some evidence that dogs and humans may metabolize some o-tolidine based dyes to the parent compound. The evidence is not definitive in all cases because the parent compound, o-tolidine, may sometimes be present in the dyes as a trace level contaminant. (10) Lynn et al. studied the metabolism of four o-tolidine- based dyes, Direct Red 2, Direct Red 39, Direct Blue 25, and Acid Red 114, in female dogs and rats. (19) Dogs administered the latter two dyes excreted o- tolidine in the urine. The authors reported that the amount of o-tolidine recovered in the urine exceeded that which could have been contributed by o- tolidine contamination alone.

In the rat, Direct Blue 25 was metabolized to o-tolidine and excreted at concentrations comparable with those observed in dogs; only trace amounts were excreted following administration of Acid Red 114. Neither the dog nor the rat excreted quantifiable amounts of o-tolidine in the urine following the administration of Direct Red 39 or Direct Red 2.

Boeniger reported finding o-tolidine in the urine of two workers in a dye manufacturing plant. (10) These employees worked with o-tolidine-based dyes and not o-tolidine itself. The o-tolidine in the urine in both of these studies may have resulted from o-tolidine metabolism of the dyes or from o-tolidine contamination in the dyes.

o-DIANISIDINE and o-DIANISIDINE-BASED DYES

Evidence of Carcinogenicity

Hadidian et al. administered o-dianisidine hydrochloride by gavage to rats for 1 year. (32) Tumors developed in the Zymbal’s gland, skin, mammary gland, stomach, intestinal tract, and bladder. Most tumors developed after 8 months. The control animals had a relatively low spontaneous tumor rate except for interstitial cell tumors.

Saffiotti et al. and Sellakumar et al., working together, fed 0.1% or 1.0% o- dianisidine to two groups of 60 Syrian Golden hamsters of both sexes throughout their lifetime. (33,34) After 2 years, one tumor of the urinary bladder was found in a hamster fed at the 0.1% level. Forestomach papillomas developed in 57% of the 60 hamsters fed at the 1.0% level. (34) The spontaneous incidence of forestomach papillomas was 2% in the control group of 60 hamsters. [See Note 4]

Pliss administered o-dianisidine to rats by gavage for 13 months. (26,27) In the surviving animals, 3 of 18 developed tumors. None of the 50 control rats developed spontaneous tumors. IARC concluded that o-dianisidine was carcinogenic in rats after oral administration. (35)

Metabolism of o-Dianisidine-Based Dyes to o-Dianisidine

There is evidence that dogs, rats, and humans may metabolize some o-dianisidine- based dyes to the parent compound. As in the case of the o-tolidine-based dyes, a residual amount of the parent compound may be present in the dye. (19) Lynn et al. studied the metabolism of the o-dianisidine-based byes, C.I. Direct Blue 1 and C.I. Direct Blue 15, in female mongrel dogs and rats. (19) Following the administration of the dyes, o-dianisidine was recovered in the urine of both species. The amount of o-dianisidine recovered in the urine exceeded that which could have been contributed by o-dianisidine contamination alone, according to the authors.

Genin studied the metabolism of two o-dianisidine based dyes, C.I. Direct Blue 15 and Direct Blue Photostable KU, in rats and found o-dianisidine was excreted in the urine. (20) In the same study, Genin reported that he found o-dianisidine in the urine of 3 of 22 workers who dried and ground two dianisidine-based dyes, C.I. Direct Blue 15 and Direct Blue Photostable KU. Boeniger reported finding o-dianisidine in the urine of a worker in a dye manufacturing plant. (10) This employee worked with o-dianisidine-based dyes and not with o-dianisidine itself. The o-dianisidine in the urine may have resulted from metabolism of the dyes or from contamination in the dyes.

o-Dianisidine is used as the starting material in the manufacture of the o- dianisidine-based dyes listed in Appendix IIB. It has been reported that some of these dyes may no longer contain the methoxy group characteristic of the o-dianisidine moiety as a major component in the dye due to chemical reactions with metals such as copper. (36) Based on structural considerations, it is unlikely that metalized o-dianisidine dyes would metabolize to o-dianisidine. However, the amount of residual o-dianisidine in these dyes is unknown at this time. The contribution of the metal to subsequent toxicity is also unknown at this time.

Recommendations

From the available evidence OSHA and NIOSH conclude that benzidine based dyes are potential human carcinogens. OSHA and NIOSH recommend that worker exposure to these dyes be reduced to the lowest feasible level. The available literature on dyes based on o-tolidine and o-dianisidine, while less extensive and definitive than that for benzidine-based dyes, suggests that these compounds and/or their contaminants may present a cancer risk to workers and should be handled with caution and exposure minimized. Workers should be informed of the potential of dyes based on benzidine, o-tolidine, and o-dianisidine to affect their health.

Several actions should be taken by employers, employees, and their physicians in order to protect workers from exposure to benzidine-, o-tolidine-, and o- dianisidine-based dyes.

I. Employers should:

1. Substitute, wherever possible, other less toxic dyes for benzidine- based dyes. Although the literature is less definitive and less extensive in supporting the carcinogenicity of o-tolidine and o- dianisidine-based dyes, OSHA and NIOSH recommend, as a prudent public health measure, substitution of less toxic dyes wherever possible. Caution should be exercised in selecting replacements. Full consideration should be given to the potential toxic effects of the substitutes.
2. Establish, where substitution is not feasible, appropriate and feasible engineering controls for all these chemicals. Engineering controls may include the use of closed process systems, liquid metering systems, walk-in hoods, and specific local exhaust ventilation. Suitable collectors should be used to prevent ambient air contamination.
3. Ensure that good housekeeping procedures and industrial hygiene practices are used to keep the work environment free of accumulated dyes and to reduce the exposure of all workers to the dyes. These procedures include, in part, the use of dyes in the form of pellets, pastes, and liquids to reduce potential exposure to dusts.
4. Establish restricted areas (with appropriate warning signs) for activities that involve occupational exposure to these dyes. Access to these restricted areas should be limited to employees who have been properly informed of the potential hazards and of proper control measures.
5. Inform all employees working with these dyes, or mixtures containing them, of the possible adverse health effects that may result from exposure to them and of acceptable ways to reduce that exposure.
6. Provide all employees who may be exposed to these dyes with a copy of this Health Hazard Alert.
7. Place all employees with occupational exposure to these dyes under a medical monitoring program that includes a medical history and periodic physical examinations. Each examining physician should be provided with a copy of this Health Hazard Alert.
8. Provide washroom or shower facilities and change rooms for employees to remove residual chemical from themselves after leaving the work area where exposure occurs. Cleaning compounds that contain strong reducing agents, such as sodium hydrosulfite, should not be used for skin decontamination.
9. Monitor employee exposure to these chemicals routinely. Exposure surveys should be made to establish the extent of exposure and the effectiveness of controls. An analytical method for quantifying benzidine-based dyes in the presence of other azo type dyes and diazonium compounds has been recently developed by NIOSH. The details of this method are available from: Publication Dissemination, Division of Technical Services, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, Ohio 45226. The NIOSH Manual of Analytical Methods also may be helpful to those developing programs to monitor employee exposures. (37,38)
10. Provide and require personal protective clothing to be used as an interim measure while engineering controls are being installed. Whenever employees leave the area, their protective clothing should be placed in a suitably marked and closed container for disposal or laundering. Laundry personnel should be made aware of the potential hazard from handling contaminated clothing.
11. Provide respiratory devices. Table 2 contains acceptable respirators that may be used to reduce exposure.

II. Employees should:

1. Use the correct safety equipment and protective devices as provided by the employer.
2. Wash exposed areas of the body with soap and water upon leaving the restricted area. Cleaning compounds that contain strong reducing agents should not be used because benzidine or other harmful products could be formed on the skin.
3. Dispose of protective clothing in the manner prescribed by the employer.
4. Report sign or symptoms of health problems to your physician if you suspect that you may be exposed to these chemicals.

III. Physicians should:

1. Obtain occupational and exposure histories.
2. Obtain a medical history with special emphasis on complaints associated with the urinary tract and hepatic systems.
3. Perform a physical examination with emphasis on the renal and hepatic systems.
4. Obtain laboratory studies for liver and renal function and a urinalysis that includes microscopic examination of the sediment.
5. Advise the employee of the results of the medical examination and laboratory analyses.

Table 2 RESPIRATORS FOR USE WITH BENZIDINE, o-TOLIDINE, and o-DIANISIDINE-BASED DYES

* Full facepieces should be used whenever eye irritation is experienced. [Return to body of table]

Notes

Note 1: C.I. indicates that the name is listed in the Colour Index, 3rd. ed., Society of Dyers and Colourists and the American Association of Textile Chemists and Colourists, Bradford, England, Vol. 1-6, 1971. [Return to main text]

Note 2: Translation from the Russian. The 100% does not indicate that it was 100% active ingredient but that it was 100% of commercial dye strength. This is probably C.I. Direct Red 13. [Return to main text]

Note 3: The abstract given in the Russian journal translates the dye as Direct Black 3. It may be Direct Black 38. [Return to main text]

Note 4: According to Saffiotti, 57% is the correct percentage of hamsters that developed forestomach papillomas, not 37% as given in the publication cited. Personal Communication, U. Saffiotti, 1979. [Return to main text]

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36. Price. R. (1970). Chemistry of metal complex dye stuff (chap. 7). In: The Chemistry of Synthetic Dyes (K. Venkataramam, ed.) New York, Academic Press, Vol. 3, 308-359.
37. NIOSH Manual of Analytical Methods 2nd ed. DHEW (NIOSH) Publication #77- 157-B, Vol I., 234-1 to 234-6, 1977.
38. NIOSH Manual of Analytical Methods 2nd ed. DHEW (NIOSH) Publication #79- 141, Vol. V, 315-1 to 315-6, 1979.
39. Kasprzak, S. DETO responses to TITC questions on dyes dated March 13, 1979. Submitted to the Toxic Substances Control Act Interagency Testing Committee by the Dyes Environmental and Toxicology Organization, June 27, 1979.
40. Synthetic Organic Chemicals–United States Production and Sales, 1977. USITC Publication 990. U.S. International Trade Commission, 1978.
41. Imports of Benzenoid Chemicals, 1978. USITC Publication 990. U.S. International Trade Commission, 1979.
42. National Occupational Hazard Survey–Survey Analysis and Supplemental Tables. DHEW (NIOSH) Publication No. 78-114. DHEW (NIOSH), 1977.

Appendices

Appendix I is a list of benzidine-based dyes reported to be commercially available in the United States. The list includes Colour Index number of the dyes, domestic production and import quantities, usage by industry, and estimated number of workers exposed. * Appendix II is a list of benzidine-, o-tolidine- and o-dianisidine-based dyes currently available in the Unites States including Colour Index number, generic names, commercial trade names, and manufacturers and distributors. ** These appendices may not be complete. The field of dye chemistry is constantly changing and products are added and removed from the market continually. Further details concerning these dyes can be found in the Colour Index and the American Association of Textile Chemists and Colorist (AATCC) Buyers Guide. Estimates of total dyes usage by industry are: For the textile industry, 66% of all dyes used in the U.S.; for the paper and pulp industry, 17%; for the leather tanners industry, 10%; and for the aqueous ink and plastics industries, about 7%.

* Taken from Appendix III, Special Occupational Hazard Review of Benzidine- Based Dyes. NIOSH Report. DHEW (NIOSH) Publication No. 80-109, 1980. [Return to main text]

** Derived from Table I (Corrected), Responses to Questions on Dyes, Submission to Interagency Testing Committee-Subcommittee to Review Dyes and Pigments by Dyes Environmental and Toxicology Organization, Scarsdale, NY, July, 1979. [Return to main text]

Appendix I

BENZIDINE-BASED DYES REPORTED TO BE COMMERCIALLY AVAILABLE IN THE UNITED STATES*

* This table lists the benzidine-based dyes that were reported as being commercially available by DETO [39] and reported as produced or imported by the US International Trade Commission (ITC) [40, 41] or those to which potential exposure was found [42]. If fewer than three manufacturers make a dye, ITC does not publish the production figures. [Return to top of table]

** A discussion of limitations of the estimation of worker exposure is contained in reference [42]. [Return to top of table]

*** This dye may also be synthesized with cresotic acid in place of salicylic acid. The Colour Index designates both dyes as Direct Orange 1. [Return to body of table]

Appendix II A

DYES DERIVED FROM BENZIDINE

Appendix II B

DYES DERIVED FROM O-DIANISIDINE

Dyes Derived from o-dianisidine Without Colour Index Generic Names
Atlantic Direct Blue 2BNB (ATL)
Atlantic Printing Black 2B Pdr. (ATL)
Atlantic Printing Black FOR Pdr. (ATL)
Neutrazoic Black 2B Pdr. (ATL)
Neutrazoic Black FOR Pdr. (ATL)
Neutrazoic Black GF 167% Pdr. (ATL)
Neutrazoic Black JN Pdr. (ATL)
Padazoic Black GLL Pdr. (ATL)
Padazoic Black RLL Pdr. (ATL)
Padazoic Black 2G 150% Pdr. (ATL)
Padazoic Blue GP Pdr. (ATL)
Padazoic Denim Indigo Blue G Pdr. (ATL)
Padazoic Navy Blue WS EX Pdr. (ATL)
Pontamine Blue WE Liq. (DUP)

Padazoic Brilliant Indigo 3B Pdr. (ATL)
Padazoic Denim Indigo Pdr. (ATL)

Atlantic Printing Brown GGN Pdr. (ATL)
Atlantic Printing Brown BR Pdr. (ATL)
Neutrazoic Brown BR Pdr. (ATL)
Padazoic Farmer Brown Pdr. (ATL)

Metalized o-Dianisidine Based Dyes

Metalized o-Dianisidine Based Dyes Without Colour Index Generic Names
Atlantic Resin Fast Blue ARL (ATL)
Atlantic Resin Fast Blue BFL (ATL)
Atlantic Resin Fast Blue BLA 150% (ATL)
Atlantic Resin Fast Blue BLC (ATL)
Atlantic Resin Fast Blue BRN (ATL)
Atlantic Resin Fast Blue 8BGI 200% (ATL)
Atlantic Resin Fast Blue 3GLL (ATL)
Atlantic Resin Fast Blue 5GLL (ATL)
Atlantic Resin Fast Blue 8GLN (ATL)
Atlantic Resin Fast Blue LBGL (ATL)
Atlantic Resin Fast Blue 6GKS (ATL)
Atlantic Resin Fast Blue 8GUM (ATL)
Atlantic Resin Fast Blue 9GLR (ATL)
Atlantic Resin Fast Blue UGLL (ATL)
Atlantic Resin Fast Blue FFBL (ATL)
Atlantic Resin Fast Blue GUL (ATL)
Atlantic Resin Fast Grey LVL (ATL)
Superlitefast Grey LVL (CKC)

Superlitefast Rubine WLKS (CKC)

Appendix II C

DYES DERIVED FROM o-TOLIDINE

Dyes Derived from o- Tolidine Without Colour Index Generic Names

Atanyl Red NJ (ATL)
Diphenyl Green BBN (CGY)
Pyrazol Dark Green 3B (S)

Direct Fast Brown BCW-NB (ATL)
Direct Fast Brown BP-NB Conc. (ATL)
Direct Brown GG-NB (ATL)
Direct Brown US-NB (ATL)

Milling Red G-NB (ATL)
Padazoic Yellow G Pdr. (ATL)
Padazoic Golden Yellow RLL Pdr. (ATL)

Padazoic Orange GR Pdr. (ATL)

Penetrating Black AM-NB (CKC)

Sandolan Red N-3B (S)

Code Letters of Manufacturers, Importers, and Distributors

[Return to Appendix II A]