????這項法案專門授權負責制定行業自主標準的同業公會ASTM International通過其內部的石膏板行業委員會來起草相關標準。這個委員會由石膏板制造商主導，四年來一直忙于內斗，無暇開展工作。委員會成員甚至無法就翻修問題房屋的基本指導原則達成一致（去年夏天該委員會實際上已進入休眠狀態，沒有再舉行任何會議）。

????這項法案實際上要求消費品安全委員會采納ASTM的標準，甚至包括后者對這些標準的修訂。法案規定，如果今后ASTM調整了硫含量標準，消費品安全委員會只有90天的時間來判斷這樣的調整是否恰當。如果審核時間超過90天，相關調整就會自動生效。

????同時，這項法案把重點完全放在“含硫量”上，這就造成美國政府無法出臺任何實質性標準來確保石膏板的安全性。這樣做的原因在于，時至今日，聯邦政府也沒能確定到底是什么讓問題石膏板釋放出腐蝕性含硫氣體。或者說，毒石膏板的問題在于它會釋放大量含硫氣體，包括硫化氫。而石膏板里釋放出這些氣體的元兇是什么？聯邦政府的調查一直沒能找到答案。

????理論上的解釋很多，比如石膏礦有毒，或者用燃煤火電廠副產品制造的人工石膏有問題；也可能是生產工藝本身存在缺陷，造成石膏板加熱不充分，或者制造商為了多賺一點兒錢而使用了有問題的添加劑；還有可能是這些因素都有影響。

????但聯邦政府開展調查至今已經過去了四年，消費品安全委員會及其他部門仍無斬獲。實際上，它們從未真正通過相關研究來尋找答案。相反，聯邦政府的注意力一直限于找出問題房屋，然后對翻修工作進行指導。

????毒石膏板事件發生后，建筑咨詢公司Foreman & Associates一直在進行調查。該公司負責人邁克爾?福爾曼稱，要判斷石膏板是否有毒，只有一個可靠的辦法。那就是測量石膏板的氣體釋放量以及這些氣體腐蝕銅等金屬的能力。如果石膏板釋放出的含硫氣體，或者說有毒氣體能腐蝕銅，那就可以斷定石膏板有毒。

????福爾曼說：“問題就在于有毒氣體的釋放。這就是為什么我們需要為石膏板制定可接受的含硫氣體釋放量標準，因為這可以避免出現這樣的問題。拿含硫量說事簡直是開玩笑。”

????福爾曼認為，在目前情況下，測量石膏板的含硫量實際上沒有任何作用，原因是沒人能確定它所含的硫會不會釋放含硫氣體。相反，氣體釋放量標準則正中要害，這樣的規定很像針對復合木板甲醛含量的立法。它既能保證營建商和消費者不會在市場上接觸到問題石膏板，也能促使制造商來尋找釋放含硫氣體的源頭，進而加以控制。

????多數參與發起《石膏板安全法案》的議員都不愿討論這項提案。而法案通過后，這些議員則又都通過熱情洋溢的新聞稿盛贊這是在石膏板問題上向前邁出的重要一步。

????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.