Ethylene glycol butyl ether (EGBE) is a versatile chemical that has been used in a variety of applications for more than 50 years. It is a particularly effective solvent because it can be used with both water-based and oil-based systems.

EGBE has also been extensively studied to determine its toxicity. Governments and independent expert groups have used that data to establish exposure levels below which no risk is expected.

The Environmental Protection Agency (EPA), on November 18, 2004, after extensive review of the compound's toxicity and exposure data, removed EGBE from its list of Hazardous Air Pollutants (HAPs) (Federal Register Vol.69 No.228, Nov.29, 2004). In announcing the decision, EPA Deputy Assistant Administrator Brenner said that delisting EGBE "will create an incentive for industry to use less toxic and less environmentally harmful compounds and focus on the pollutants that are really the most dangerous."

Recent Expert Reviews of EGBE Toxicity

EPA has several times in the past three years reviewed EGBE. The Agency adopted a Reference Concentration (RfC) for EGBE in 1999. That RfC of 13 mg/cubic meter is a level at which no appreciable risk is expected with lifetime exposure, even for susceptible individuals. EPA's review found that EGBE is neither a primary reproductive nor developmental toxicant, nor, because EPA concluded it is not mutagenic, it is not likely to cause cancer in humans. EPA found the most sensitive endpoint in rodents is hemolysis, an effect to which human red blood cells are much more resistant. The Agency used a physiologically based pharmacokinetic (PBPK) model for EGBE that has shown that human exposure high enough to cause hemolysis (effects on red blood cells) is not expected to occur in humans under any normal exposure conditions.

After that initial EPA review, a lifetime study of EGBE in mice and rats was completed by the U.S. National Toxicology Program (NTP). Although that study resulted in some excess tumors, the study itself and panel-sponsored research subsequent to the NTP study have demonstrated that the mechanisms by which these tumors were caused are unlikely to be relevant to humans.

The Agency reaffirmed its 13 mg/cubic meter RfC in removing EGBE from its list of HAPs (see more below) in November 2004. As that decision said, the Agency's recent reviews included its interpretation of the NTP study and conclusion that extensive data show that its 1999 RfC is "sufficient" to prevent any cancer risk to humans. EPA concluded that the tumors in mice were caused by mechanisms that are not relevant to human risk. See: EPA docket OAR-2003-0188 Document 0028 (http://docket.epa.gov/edkpub/index.jsp). In May 2004, an outside expert panel appointed by the Agency agreed with EPA's interpretation of the NTP study.

In June 2004, the World Health Organization's International Agency for Research on Cancer (IARC) also evaluated the NTP study and several other EGBE studies. That Agency's expert panel concluded that EGBE is not classifiable as to human cancer because there is inadequate evidence in humans and limited evidence in animals. That finding parallels EPA's conclusion that the tumors found in lifetime animal studies of EGBE are not relevant to humans. As both EPA and IARC noted, these conclusions are supported by extensive experimental work on EGBE sponsored by the Panel that was conducted at the Indiana University Medical Center and the Pacific Northwest National Laboratory.

EPA's Delisting of EGBE

On November 18, 2004, EPA removed EGBE from the Clean Air Act (CAA) list of HAPs. EGBE is thus no longer subject to Maximum Achievable Control Technology (MACT), residual risk, and other specific requirements found in the CAA.

EPA's decision to delist EGBE means that many companies that use EGBE in product formulation can do so without being subject to requirements considered inappropriate for this chemical. In announcing its decision, EPA said: "This action creates incentives for industry to use EGBE instead of other more toxic solvents." Like most solvents, EGBE continues to be regulated as a volatile organic compound (VOC) and thus its emissions must be reported on the Toxics Release Inventory.

EPA's announcement, Fact Sheet, Final Rule Federal Register, and related documents finding the NTP mouse tumors not relevant to man are available at: http://www.epa.gov/airlinks/airlinks3.html.

EPA is directed under the CAA to delist HAPs if there are "adequate data on the health and environmental effects of the substance to determine that emissions, ambient concentrations, bioaccumulation or deposition of the substance may not reasonably be anticipated to cause any adverse effects to human health or adverse environmental effects." CAA Section 112(b)(3)(C).

Applying this standard, said the Agency: "After extensively reviewing the levels of EGBE in the air Americans breathe and the health and environmental impacts associated with those levels, EPA has concluded that potential outdoor exposures to EGBE may not reasonably be anticipated to cause human health or environmental problems."

In its proposed rule, EPA had found wide margins of safety ("Hazard Quotients") between estimated maximum exposures and lowest toxicity effect levels. The Agency found maximum human exposures would be 16 to 50 times lower than the lowest level expected to pose any risk to human health. Thus, EPA concluded: "[W]e judge that the potential for human health and environmental effects [from EGBE] is sufficiently low to provide reasonable assurance that such adverse effects will not occur." See: 68 Fed. Reg. 65648 (Nov. 21, 2003).

The Glycol Ether Panel filed the EGBE petition in August 1997. EPA issued its proposed rule on November 21, 2003. The Agency received 15 favorable comments. Only three short comments, which according to EPA contained no substantive information, opposed delisting.

The delisting of EGBE corrects an over-inclusive listing of HAPs by Congress more than a decade ago. In the early 1980's, animal studies on the lowest molecular weight ethylene glycol ethers (EGME and EGEE and their acetates) raised issues about their potential reproductive and developmental toxicity. Subsequent animal studies showed that EGBE does not cause such toxicity. Nonetheless, those issues about EGME and EGEE caused a category of all ethylene glycol ethers to be included when Congress listed as HAPs 189 chemicals in the 1990 CAA Amendments.

As noted above, EPA reviewed the lifetime rodent studies conducted in the 1990's by the NTP. The Agency's Delisting Fact Sheet says the reviews by Agency scientists and a peer review panel concluded: "[H]umans do not exhibit the cell changes that lead to the EGBE-related types of tumors seen in mice. Without these cell changes, tumors do not occur." Thus, says the Agency: "EPA concluded that humans cannot reasonably be anticipated to develop tumors from environmental concentrations of EGBE."

Other Expert Reviews of EGBE

Other governments and independent expert groups have reviewed the EGBE database.

Agreeing with EPA that the tumors in the NTP study were due to mechanisms not relevant to man, the European Union (EU) expert committee on chemical labeling has determined that EGBE does not pose risks of cancer for which warning labels are appropriate. The EU is currently conducting a risk assessment on EGBE and its acetate. This is expected to be complete in 2005.

The Cosmetics Ingredient Review (CIR) Expert Advisory Panel reaffirmed their 1996 review in 2002 that EGBE is "safe in hair and nail products at concentrations up to 10.0%." Like the EU and EPA, the CIR reviewed the NTP study and found it not relevant to human risk.

Only the Canadian Ministry of Health is known to have found rodent tumors in the NTP study of EGBE possibly relevant to humans. In 2003, Canada raised questions about the relevance of the mouse tumors. The Canadian assessment is at: www.ec.gc.ca/cceb1/eng/public/glyclos_e.html

EGBE in the Environment

EGBE's characteristics when released to land, water or air have also been studied, as have potential effects on the environment (Staples, C.A., et al. Ethylene Glycol Ethers: An Environmental Risk Assessment. Chemosphere 36(7), 1585-1613 (1998)).

EGBE moves to water because of its high solubility, low volatility and minimal tendency to bind to soil or sediment. In water, it will degrade rapidly — its half-life is shown as less than two weeks. Studies using a variety of protocols have found EGBE meets the U.S. EPA definition of "readily" biodegradable in both aerobic surface waters and under typical waste treatment plant conditions. In the air, EGBE has been shown to have a half-life of less than two days.

EGBE has been found to cause toxicity in fish and other organisms only at the high concentrations. These concentrations are high enough so that EGBE can be classified in U.S. EPA's "practically non-toxic" category. Tests with algae, yeast, protozoa, bacteria and fungi also provide evidence that EGBE would not be expected to cause adverse environmental effects except at concentrations well above any that have been found in the environment. The Canadian Government in 2003 found that EGBE would not cause harmful effects on the environment.

EPA's review and decision removing EGBE from the CAA list of HAPs also found EGBE emission unlikely to cause any adverse effects on the environment.

Occupational Exposure Limits (2004 Values for EGBE)

Advisory and regulatory groups around the world have established occupational exposure limits for EGBE and cautioned against skin contact. Some groups' limits are provided below. Consult listed groups for further information on these limit values.

American Conference of Governmental Industrial Hygienists (ACGIH TLV, USA)
 20 ppm
 97 mg/m3
 
Permissible Exposure Limit (OSHA - PEL, USA)
 50 ppm
 242 mg/m3
 
Indicative Limit Value (ILV - EU)
 20 ppm
 97 mg/m3
 
Maximale Arbeitsplatz-Konzentration (MAK- Germany)
 20 ppm
 97 mg/m3
 
Occupational Exposure Standard (OES - UK)
 20 ppm
 121 mg/m3
 
EGBE air concentrations measured in a number of workplaces show levels are typically well below these limits.

For further information on EGBE toxicity, refer to the following documents:

Boatman RJ and Knaak JB, Patty's Toxicology, Chapter 86 John Wiley and Sons (2001); and Boatman RJ. Corley RA, Green T, Klaunig JE and Udden MM, Review of the Tumorogenicity of 2-Butoxethanol in B6C3F1 Mice and its Relevance for Human Risk Assessment, J. Tox. Env. Health, Part B, 7:385-398 (2004).

This document summarizes information from the technical, scientific literature and is intended for reference by medical, scientific and regulatory personnel. The Ethylene and Propylene Glycol Ethers Panel of the American Chemistry Council and its member companies believe that this document is, as of the date of its publication, a technically accurate summary of available scientific information. However, the Panel and its member companies do not make any warranties, express or implied, regarding the completeness or accuracy of the information presented and assume no responsibility or liability for its use. New information may be developed subsequent to the publication of this summary, which may render the summary incomplete or inaccurate. The Panel and its member companies assume no responsibility to amend, revise, retract, or update the summary to reflect any such information that may become available after its publication.

June 2005

This information is brought to you by the member companies of the American Chemistry Council Ethylene and Propylene Glycol Ethers (EGE/PGE) Panel: Arch Chemicals Inc., The Dow Chemical Company, Eastman Chemical Company, Equistar Chemicals, LP, and Lyondell Chemical Company.

Ethylene glycol ethers are a group of chemicals with a wide variety of uses. Primary uses include solvents in paints, cleaners and inks. Some ethylene glycol ethers are recommended for use only in industrial applications; others have wide use in industrial, commercial and consumer applications.

All the commercially marketed ethylene glycol ethers have been tested in animal studies to assess potential toxicity to humans. Summaries of toxicity studies of ethylene glycol ethers conducted by numerous government, academic and industry researchers are available in Patty's Industrial Hygiene and Toxicology, Fifth Edition, Volume 7, Chapter 86 (2001) and in ECETOC Technical Report No. 64, The Toxicology of Glycol Ethers and Its Relevance to Man (2005). These data have been used to develop recommendations for use.

Ethylene glycol ethers have received some media attention and are included on some government lists of hazardous substances because the smallest molecular weight ethylene glycol ethers were found to cause adverse male and female reproductive effects and birth defects in rodent studies. Those particular ethylene glycol ethers have not been used in consumer products in the United States for the past 20 years. Other glycol ethers have been tested similarly, have been found not to cause such effects, and are used in a wide variety of products.

ETHYLENE GLYCOL ETHERS INFORMATION UPDATE

The Environmental Characteristics
of Ethylene Glycol Butyl Ether (EGBE)

The available scientific data show that ethylene glycol butyl ether (EGBE), a widely used solvent for many applications, is not persistent in the environment, does not bioaccumulate, is practically non-toxic to aquatic organisms, and therefore causes little or no adverse environmental impact. These characteristics complement EGBE's other attributes: minimal if any potential for adverse effects on humans when recommended precautions are followed, and a unique ability to serve as a solvent for both polar and non-polar compounds.

Physical Properties

EGBE tends to remain dissolved in water because of its low volatility (vapor pressure between 0.6 and 0.88 mm Hg) and minimal tendency to bind to soil (log Kow of 0.81 to 0.83). When dissolved in water, EGBE will accumulate only negligibly in aquatic organisms (calculated bioconcentration factor of 2.5).

Degradation

EGBE does not persist in the environment. In air, it has a half-life of less than two days; in water, its half-life is less than two weeks. Studies using a variety of protocols classify EGBE as "readily" or "inherently" biodegradable in both aerobic surface waters and under typical waste treatment plant conditions.

Aquatic Toxicity

Results from tests with EGBE on aquatic organisms fall into EPA's "practically non-toxic" category. Acute toxicity tests in seven different fish have found all lethal concentrations (LC50's) to be at least 800 milligrams/liter (mg/L); tests with aquatic invertebrates found LC50's of at least 500 mg/L. Tests with algae, yeast, protozoa, bacteria and fungi also show that EGBE will not cause adverse effects except at very high concentrations.

Putting It All Together

Because of its physical properties, most EGBE released to the environment is reasonably expected to remain in the water column, where it will rapidly degrade. As a result, EGBE appears not to be persistent and its concentration in the environment is very unlikely ever to be high. Adverse effects upon fish or other aquatic organisms will thus be near to non-existent. Indeed, all reported levels of EGBE in the environment are below concentrations at which toxicity would occur. In sum, EGBE is a not persistent, not bioaccumulative, "practically non-toxic" — a solvent that thus offers desirable environmental attributes.

This document summarizes information from the technical, scientific literature and is intended for reference by medical, scientific and regulatory personnel. The Ethylene and Propylene Glycol Ethers Panel of the American Chemistry Council and its member companies believe that this document is, as of the date of its publication, a technically accurate summary of available scientific information. However, the Panel and its member companies do not make any warranties, express or implied, regarding the completeness or accuracy of the information presented and assume no responsibility or liability for its use. New information may be developed subsequent to the publication of this summary, which may render the summary incomplete or inaccurate. The Panel and its member companies assume no responsibility to amend, revise, retract, or update the summary to reflect any such information that may become available after its publication.

乙二醇单丁醚（EGBE）是一种用途广泛的化学产品而且在各种领域使用了50多年。它是一种特效溶剂，既可以用在水基物质中使用，也可以用于油基物质。

对乙二醇单丁醚的毒性也进行过大范围的研究。政府和独立组织都曾使用这些数据，来确定在低于这些数值的情况下，是没有毒性的。

2004年11月18日，美国环境保护局（EPA）在对化合物的毒性和已经公布的数据进行了全面审查之后，宣布乙二醇单丁醚不再属于有害空气污染物（HAPs）名单（2004年11月29日，联邦记录第69卷）上的有害物质。在宣布这一决定的时候，环境保护局助理副局长勃伦纳说，将乙二醇单丁醚从有害污染物名单上删除“不但给使用低毒性化合物和对环境危害较轻化合物的行业带来了生机，也促使人们把注意力放到那些真正有毒性的化合物上。” 

目前专家对乙二醇单丁醚毒性的审查

环境保护局曾经在过去三年中几次对乙二醇单丁醚进行审查。环保局在1999年就采用了一套针对乙二醇单丁醚的参照浓度（RfC）。该参照浓度设定为每立方米13毫克，这是预计对人终生无害的水平，即使是对容易过敏的人也同样适用。环境保护局在审查中发现，乙二醇单丁醚既不是产生毒性的主要原因，也不是导致毒性扩大的主要原因，同时因为环境保护局把它列为非诱导有机体产生突变的物质，它似乎也不会引发人类的癌症。环境保护局发现，在实验中大多数啮齿动物的明显反应是溶血现象，而由于人类的红细胞抵抗力更强，这种效果在人类身上的影响不大。环保局使用了一个针对乙二醇单丁醚的生理代谢动力学（PBPK）模型，显示出对人类的红细胞产生影响，引发溶血现象的剂量要大得多，而在正常状态下不会达到那种剂量。 

在环境保护局的那些初步的审查以后，美国国家毒理学规划处（NTP）也完成了乙二醇单丁醚在鼠科动物身上进行的寿命研究试验。虽然在试验中有些老鼠身上长出了过多的肿瘤，这个实验以及后来国家毒理学规划处进行的辅助实验，全都证明导致肿瘤产生的机制，不可能在人类身上产生类似的效果。

环保局在2004年11月将乙二醇单丁醚从有害空气污染物名单上取消的时候，重申了它的每立方米13毫克的参照浓度的有效性。有关有害空气污染物名单的详细情况，请看下文。正中该决定所说的，环保局最近的审查包括了国家毒理学规划处的说明性实验，并得出结论说，该局的1999年参照浓度对预防人类癌变的风险是“足够的”。环境保护局推断，在老鼠身上产生肿瘤的机制不会让人类冒类似的风险。参看：环境保护局第0028号文件OAR-2003-0188号摘要（http：//docket.epa.gov/edkpub/index.jsp）。2004年5月，环保局委任的一个局外专家小组，也同意环境保护局对国家毒理学规划处的研究结果进行的说明。

2004年6月，世界卫生组织的国际肿瘤研究机构（IARC）也评估了国家毒理学规划处的研究结果，同时也对其它几个针对乙二醇单丁醚的研究结果进行了评估。该组织的专家小组得出结论，乙二醇单丁醚不应划分到导致人类癌变的类别，因为没有充分的人身实验证据，在动物身上得出的实验数据也很有限。这一结论，与环境保护局在动物身上进行乙二醇单丁醚寿命实验并发现肿瘤，并得出人类并不会因此发生癌变的结论桴鼓相应。正如环境保护局和国际肿瘤研究机构共同指出的那样，这些结论的背后，有大范围的乙二醇单丁醚实验相支持，这些实验都是由印第安纳大学医学中心和太平洋西北国家实验室主持的。

环境保护局对乙二醇单丁醚的除名

2004年11月18日，环境保护局将乙二醇单丁醚从《清洁空气法》（CAA）规定的有害空气污染物名单上除名。从此乙二醇单丁醚不再受《清洁空气法》中规定的最大化控制技术 （MACT）、残余物风险和其它特别要求的限制。

环境保护局将乙二醇单丁醚除名的决定意味着许多在生产过程中使用乙二醇单丁醚的公司可以放开手脚，不再受原来那些对这种化学产品的种种不当要求的限制。在宣布这一决定的同时，环境保护局说道：“这一行动将为使用乙二醇单丁醚代替其它毒性较强的溶剂的行业带来生机。”和许多溶剂一样，乙二醇单丁醚还会被当作挥发性有机化合物（VOC）进行管理，它的排放必须由“有毒物质排放清单”做出汇报。

环境保护局的公告、情况说明书、最终法案联邦公告、以及国家毒理学规划处老鼠肿瘤对人类没有影响的有关报告可以在以下网页中找到：http://www.caa.gov/airlinks/airlinks3.html。

环境保护局得到指示，根据《清洁空气法》将有关物质从有害空气污染物名单上除名，只要该物质“有足够的对健康和环境产生的影响的数据证明，该物质的排放、在周围环境中的集结、在生物体内的积累或者沉积不会对损害人体健康或者对环境带来不良影响。”《清洁空气法》第112条（b）（3）（C）款。

在执行这条标准的过程中，环保局宣布：“在对美国居民呼吸的空气中各种浓度的乙二醇单丁醚进行全面的审查，并对相应浓度对健康和环境的影响进行全面的审查之后，环境保护局得出结论，乙二醇单丁醚的潜在露天暴露不会给人类的健康少环境带来可能的危害。” 

环境保护局在它的法规提案里面，在受影响的最大值和最低毒性作用水平之间，为安全性（“危害商数”）规定了范围很广的机动处理权力。环保局发现人体接触的次数应当比预计的没有健康风险的次数低16到50次。因此，环境保护局做出结论：“本局认为[乙二醇单丁醚] 对人类健康和环境影响的潜在作用非常的弱，因此有理由认为这类不良影响不会产生。”参见（2003年11月21日）联邦公告68-65648号文件。

乙二醇醚研究小组于1997年8月完成了乙二醇单丁醚的情况报告。环境保护局于2003年11月21日提交了它的规定提案，随后收到了15条赞同意见。反对意见只有三条，内容也不多，都是批评环境保护局没有提供实质性的资料，反对除名的意见。 

将乙二醇单丁醚从名单上删除，纠正了有害空气污染物名单过长的弊病，这个名单是十多年前由国会制定的。早在二十世纪八十年代初期， 在动物身上进行的最简单的乙二醇醚化合物（乙二醇甲醚、乙二醇乙醚及其醋酸盐）的研究，产生了一些有关这些化学品可能的毒性再生和扩展的可能性的报告。后续的动物研究显示，乙二醇单丁醚并不会产生这种毒性。尽管这样，那些关于乙二醇甲醚和乙二醇乙醚的报告还是让所有类别的乙二醇醚上了国会的黑名单，名列1990年《清洁空气法》修正案中提到的189种有害空气污染物之中。

正如上面所提到的，环境保护局重新审查了国家毒理学规划处1990年对啮齿动物的寿命研究。环保局除名情况说明书中说，环保局的科学家和同级的研究小组做出结论：“没有现象表明，虽然乙二醇单丁醚及其同类化合物会在老鼠身上产生肿瘤，但不会导致人体发生癌变。既然没有癌变，也就不会产生肿瘤。”因此，环保局宣布：“环境保护局得出结论，人类不会由于乙二醇单丁醚在环境中的集中而引发肿瘤。”

其他专家对乙二醇单丁醚的审查

其它政府和独立专家小组也对乙二醇单丁醚数据进行了审查。 

美国环境保护局对国家毒理学规划处的肿瘤研究结果，即类似机制不会对人体产生类似影响的结论，得到欧盟（EU）化学制品标签专家委员会的赞同，该委员会确定乙二醇单丁醚不会产生标签上提示的致癌可能。欧盟正在对乙二醇单丁醚及其醋酸盐进行风险评估，评估工作有望于2005年完成。

美国化妆品成分审查委员会（CIR）专家建议小组在2002年对他们1996年的研究报告做了审查，得出的结果为“如果头发和指甲用品中的乙二醇单丁醚浓度不超过10.0%，都是安全的。” 与欧盟和环境保护局一样，美国化妆品成分审查委员会审查了国家毒理学规划处的研究，同样认为对人体无害。

目前已知，只有加拿大卫生部在国家毒理学规划处的乙二醇单丁醚啮齿动物肿瘤研究中发现，乙二醇单丁醚可能会对人类带来危害。2003年，加拿大提出针对老鼠出肿瘤的质疑。加拿大的评估发表在网站：www.ec.gc.ca/cceb1/eng/public/glyclos_e.html 上。

环境中的乙二醇单丁醚

对乙二醇单丁醚排放到土壤、水和空气中以后表现出来的特性，以及它对环境的影响已经进行过研究（主要成份C.A.，以及其它：乙二醇醚：环境风险评估。臭氧层36（7）, 1585-1613 （1998））。

乙二醇单丁醚由于其高溶解性、低挥发性和不易与土壤或沉积物结合的特性，因而大多聚集在水中，而在水里的时候，它的降解速度很快——其半衰期不到两个星期。通过各种实验方案进行的研究表明，乙二醇单丁醚不论是在有氧的水面、或者是在典型的废物处理厂条件下，都符合美国环境保护局关于“易于”生物降解的规定。在空气中，已经发现乙二醇单丁醚的半衰期不到两天。

只有在浓度很高的情况下乙二醇单丁醚才会对鱼类和其它生物产生毒性，这种情况由于对乙二醇单丁醚的浓度要求非常高，所以已被列入美国环境署的“特殊无毒”类别。通过对海藻、酵母菌、原生动物、细菌以及霉菌蛋白酶的测试，同样证明乙二醇单丁醚不会给环境带来不良影响，除非环境中的乙二醇单丁醚浓度大大高于历史记录。加拿大政府在2003年也发现乙二醇单丁醚不会对环境带来危害。Tracy

只有在浓度很高的情况下，才发现乙二醇单丁醚会对鱼类和其它生物产生毒性，在这种情况下乙二醇单丁醚的浓度之高，已经可以被列入美国环境保护局“完全无毒（practically non-toxic）”的类别。通过对海藻、酵母菌、原生动物、细菌以及霉菌蛋白酶的测试，同样证明乙二醇单丁醚不会给环境带来不良影响，除非环境中的乙二醇单丁醚浓度大大高于历史记录。加拿大政府在2003年也发现乙二醇单丁醚不会对环境带来危害。

环境保护局的审查以及将乙二醇单丁醚从《清洁空气法》有害空气污染物名单上取消，同样也是因为乙二醇单丁醚的排放不可能给予环境还来不良影响。

职业接触极限（2004年制定的乙二醇单丁醚值）

世界各地的指导和规章制定机构已经对乙二醇单丁醚制定出了职业接触极限值，并规定了皮肤接触警告值。某些机构的数据如下表所示。可以咨询下表中列出的机构，以获得有关这些极限值的更详细信息。

美国政府工业卫生工作者会议（ACGIH TLV，美国）
 20 ppm
 97 mg/m3
 
允许接触极限（美国职业安全与卫生管理局 – PEL，美国）
 50 ppm
 242 mg/m3
 
极限值说明（ILV - 欧盟）
 20 ppm
 97 mg/m3
 
工作场所最大允许浓度（MAK- 德国）
 20 ppm
 97 mg/m3
 
职业接触标准（OES – 英国）
 20 ppm
 121 mg/m3
 
在各种各样的工作场地中测量到的乙二醇单丁醚空气浓度，都大大低于上述极限值。

关于乙二醇单丁醚毒性的更详细的信息，请参考以下文献：

R·J·波特曼和J·B·肯纳克，馅饼毒理学，第86章，约翰·威利父子公司2001年出版；R·J·波特曼、R·A·克雷、T·格林、J·E·克劳宁和M·M·乌登，对B6C3F1老鼠乙二醇单丁醚诱发肿瘤病理的审查，以及该病理对人类健康风险评估的价值，J·托克斯，《卫生》（英文版B部分，7：385-398（2004）。

本文总结了技术和科技文献的资料，对医学、科研和规章制定的人员起到参考作用。美国化学品委员会的乙烯基和丙烯基乙二醇醚研究小组及其会员公司认为，这个文件，包括文件公布的数据，都是根据现有科学资料所得出的最准确的数据。 但是该小组及其会员公司不会对所公布数据的完整性和准确性做任何承诺、说明或者暗示，也不会为这些数据的使用承担责任和义务。这个摘要的后续实验会产生新的数据，并对摘要中不完全和不正确的地方进行修正。该小组及其会员公司在摘要出版以后，没有对摘要中的数据进行修改、校正、取消或者更新的义务和责任。

2005年6月

本资料由美国化学品委员会乙烯基和丙烯基乙二醇醚小组及其会员公司发表：奥麒化工、道化学公司、伊斯特曼化学公司、埃魁斯特化学公司、LP和利安德化学公司。

乙二醇醚是一组应用非常广泛的化学制品，其主要用途包括：涂料溶剂、清洁剂和墨水等。某些乙二醇醚只用于工业用途；其它乙二醇醚广泛地应用于工业、商业用途和消费品。

所有投入商业市场的乙二醇醚都在动物身上进行过潜在毒性的研究。这些乙二醇醚研究的摘要由很多政府部门、学术单位和工业研究人员管理，其内容可以在《馅饼业的卫生和毒理》（2001年第五版第七卷第86章）和欧洲生态毒理学和毒理学中心（ECETOC）技术报告（2005年第64号乙二醇醚的毒性及其对人体的影响）。这些数据已经用于产品的使用说明。

乙二醇醚已经受到媒体的关注，并被列入某些政府的有害物质名单，原因是发现摩尔量最小的乙二醇醚可能会对男性和女性生殖产生不良影响，并通过对啮齿动物的研究发现它对动物的出生会产生不良影响。这些乙二醇醚在美国过去二十年中一直用于消费品。其它的乙二醇醚也经过同样的测试，但是发现不会产生类似的影响，因此用于更广泛的用途。

乙二醇醚资料的更新

乙二醇单丁醚（EGBE）
 的环境特点

瑞有的科学数据显示，乙二醇单丁醚（EGBE）这种用途广泛的化学产品，不会在环境中长期存在，不会在生物体内积累，对水生生物完全无毒，因此对环境的不良影响极轻或者根本没有。除了上述特点外，乙二醇单丁醚的其它品质还包括：在按照规定操作的情况下，对人体的不良影响可以降到最低，同时它也具备独特的特点，可以同时用于极性化合物和非极性化合物的溶剂。

物理性质

乙二醇单丁醚由于挥发性低（蒸汽压力介于0.6和0.88毫米汞柱之间），易于溶解于水，并且不易与土壤结合（辛醇/水分配系数（log Kow）值为0.81至0.83）。在溶于水中时，乙二醇单丁醚在水生生物体内的积累量可以忽略不计（计算出的生物积累量值为2.5）.

降解

乙二醇单丁醚在环境中不会持续存在。在空气中，它的半衰期不到两天，在水中的半衰期少于两个星期。通过各种实验方法把乙二醇单丁醚划分为“易于”或者“天生”可生物降解的类别，这种分类同时适用于有氧的水面、或者是在典型的废物处理厂条件。

水生生物毒性

环境保护局将乙二醇单丁醚水生生物测试结果归类为“完全无毒”。分别在七条鱼身上进行的急性毒性测试表明，致命浓度（半数致死剂量）应当至少达到800毫克/升（mg/L）；对无脊椎动物的测试，致命浓度（半数致死剂量）应当高于500 mg/L。在对藻类、酵母菌、原生动物和霉菌蛋白酶的测试，同样说明除非在极高的浓度下，乙二醇单丁醚不会对环境造成不良影响。

综述

由于本身的物理性质，因为能够快速降解不会长时间保存在水中，所以大多数乙二醇单丁醚都排放到环境中。结果是，乙二醇单丁醚表现出不稳定性，而且很难在环境中积累到很高的浓度。对鱼类和水生生物的不良影响因此可以忽略。不过，有关环境中的乙二醇单丁醚的各种报告都是在大大低于危害浓度的情况下做出的。总而言之，乙二醇单丁醚是一种不稳定的、无生物积累的、“完全无毒”的溶剂，而且有令人满意的环保特性。

本文总结了技术和科技文献的资料，对医学、科研和规章制定的人员起到参考作用。美国化学品委员会的乙烯基和丙烯基乙二醇醚研究小组及其会员公司认为，这个文件，包括文件公布的数据，都是根据现有科学资料所得出的最准确的数据。 但是该小组及其会员公司不会对所公布数据的完整性和准确性做任何承诺、说明或者暗示，也不会为这些数据的使用承担责任和义务。这个摘要的后续实验会产生新的数据，并对摘要中不完全和不正确的地方进行修正。该小组及其会员公司在摘要出版以后，没有对摘要中的数据进行修改、校正、取消或者更新的义务和责任。