中国含硫石膏板惹祸，美国国会遇立法难题

    这项法案专门授权负责制定行业自主标准的同业公会ASTM International通过其内部的石膏板行业委员会来起草相关标准。这个委员会由石膏板制造商主导，四年来一直忙于内斗，无暇开展工作。委员会成员甚至无法就翻修问题房屋的基本指导原则达成一致（去年夏天该委员会实际上已进入休眠状态，没有再举行任何会议）。

    这项法案实际上要求消费品安全委员会采纳ASTM的标准，甚至包括后者对这些标准的修订。法案规定，如果今后ASTM调整了硫含量标准，消费品安全委员会只有90天的时间来判断这样的调整是否恰当。如果审核时间超过90天，相关调整就会自动生效。

    同时，这项法案把重点完全放在“含硫量”上，这就造成美国政府无法出台任何实质性标准来确保石膏板的安全性。这样做的原因在于，时至今日，联邦政府也没能确定到底是什么让问题石膏板释放出腐蚀性含硫气体。或者说，毒石膏板的问题在于它会释放大量含硫气体，包括硫化氢。而石膏板里释放出这些气体的元凶是什么？联邦政府的调查一直没能找到答案。

    理论上的解释很多，比如石膏矿有毒，或者用燃煤火电厂副产品制造的人工石膏有问题；也可能是生产工艺本身存在缺陷，造成石膏板加热不充分，或者制造商为了多赚一点儿钱而使用了有问题的添加剂；还有可能是这些因素都有影响。

    但联邦政府开展调查至今已经过去了四年，消费品安全委员会及其他部门仍无斩获。实际上，它们从未真正通过相关研究来寻找答案。相反，联邦政府的注意力一直限于找出问题房屋，然后对翻修工作进行指导。

    毒石膏板事件发生后，建筑咨询公司Foreman & Associates一直在进行调查。该公司负责人迈克尔•福尔曼称，要判断石膏板是否有毒，只有一个可靠的办法。那就是测量石膏板的气体释放量以及这些气体腐蚀铜等金属的能力。如果石膏板释放出的含硫气体，或者说有毒气体能腐蚀铜，那就可以断定石膏板有毒。

    福尔曼说：“问题就在于有毒气体的释放。这就是为什么我们需要为石膏板制定可接受的含硫气体释放量标准，因为这可以避免出现这样的问题。拿含硫量说事简直是开玩笑。”

    福尔曼认为，在目前情况下，测量石膏板的含硫量实际上没有任何作用，原因是没人能确定它所含的硫会不会释放含硫气体。相反，气体释放量标准则正中要害，这样的规定很像针对复合木板甲醛含量的立法。它既能保证营建商和消费者不会在市场上接触到问题石膏板，也能促使制造商来寻找释放含硫气体的源头，进而加以控制。

    多数参与发起《石膏板安全法案》的议员都不愿讨论这项提案。而法案通过后，这些议员则又都通过热情洋溢的新闻稿盛赞这是在石膏板问题上向前迈出的重要一步。

    The bill specifically authorized a drywall working group within ASTM International, a trade association that develops voluntary standards, to write the rules. That group, dominated by drywall manufacturers themselves, has been mired in delay and in-fighting for years – unable to even agree on basic guidelines for repairing homes with bad drywall. (As of this past summer, it essentially went dormant and stopped meeting.)

    The bill calls for the CPSC to essentially defer to ASTM's own standards, even if they later change. If the industry group changes its "sulfur content" standard in future years, the CPSC will have only 90 days to review it and determine if it's inadequate, according to the bill. Otherwise, those changes will go into effect.

    But by focusing on "sulfur content" at all, the new legislation ensures no meaningful standard will be developed to keep drywall safe. That's because to date, the federal government hasn't determined what's actually causing the bad drywall to release corrosive sulfur gases. In other words, the problem with contaminated drywall is it releases high levels of sulfur gases, including hydrogen sulfide. What within the drywall is responsible for those emissions? The federal investigation has never answered that question.

    Theories have abounded, including everything from contaminated gypsum mines, to problems with synthetic gypsum made from the byproduct of coal-fired power plants. The root cause could even be with faulty production processes themselves, where the drywall may have been inadequately heated or where bad additives were used by manufacturers looking to stretch a dollar. It could be a combination of such factors.

    But four years after the federal government began its investigation, the CPSC and other agencies have not reached an answer. In fact, they never truly instituted the research to find one. Instead, the federal focus has been limited to developing a checklist for identifying affected houses and then guidance for repairing them.

    There is only one definitive way to test whether a piece of drywall is contaminated, says Michael Foreman, head of Foreman & Associates, which has been investigating tainted drywall since the crisis first emerged. Measure the levels of gases the drywall releases, and their ability to corrode metals such as copper. If the sulfur gas emissions, also known as out-gassing, can corrode copper, then the drywall is conclusively tainted.

    "The out-gassing is the only thing that matters," Foreman says. "That's why what you need is a standard for what's an acceptable level of sulfur gas emissions from drywall. That would keep this from happening. Looking at sulfur content is a joke."

    Measuring sulfur content inside a piece of drywall is essentially useless at this point, Foreman says, because nobody knows for sure if elemental sulfur causes the gases. Instead, a standard based on the emissions – much like what's been enacted for formaldehyde levels allowed from composite wood products – would get to the root of the problem. It would both keep builders and consumers safe from bad drywall entering the marketplace, and would compel manufacturers to figure out what materials caused the emissions in order to could control them.

    Most lawmakers involved in sponsoring the Drywall Safety Act were unwilling to answer questions about their new legislation, despite issuing glowing press releases after its passage touting it as an important step in the drywall saga.